Bumped version for 0.5.1 release

Refs #294

.gitignore

@@ -1,4 +1,15 @@
+.*
+!.gitignore
 *.pyc
 .*.swp
+*.egg
 docs/.build
 docs/_build
+build/
+dist/
+mongoengine.egg-info/
+env/
+.settings
+.project
+.pydevproject
+tests/bugfix.py

AUTHORS

@@ -0,0 +1,69 @@
+The PRIMARY AUTHORS are (and/or have been):
+
+Harry Marr <harry@hmarr.com>
+Matt Dennewitz <mattdennewitz@gmail.com>
+Deepak Thukral <iapain@yahoo.com>
+Florian Schlachter <flori@n-schlachter.de>
+Steve Challis <steve@stevechallis.com>
+Ross Lawley <ross.lawley@gmail.com>
+Wilson Júnior <wilsonpjunior@gmail.com>
+Dan Crosta https://github.com/dcrosta
+
+CONTRIBUTORS
+
+Dervived from the git logs, inevitably incomplete but all of whom and others
+have submitted patches, reported bugs and generally helped make MongoEngine
+that much better:
+
+ * Harry Marr
+ * Ross Lawley
+ * blackbrrr
+ * Florian Schlachter
+ * Vincent Driessen
+ * Steve Challis
+ * flosch
+ * Deepak Thukral
+ * Colin Howe
+ * Wilson Júnior
+ * Alistair Roche
+ * Dan Crosta
+ * Viktor Kerkez
+ * Stephan Jaekel
+ * Rached Ben Mustapha
+ * Greg Turner
+ * Daniel Hasselrot
+ * Mircea Pasoi
+ * Matt Chisholm
+ * James Punteney
+ * TimothéePeignier
+ * Stuart Rackham
+ * Serge Matveenko
+ * Matt Dennewitz
+ * Don Spaulding
+ * Ales Zoulek
+ * sshwsfc
+ * sib
+ * Samuel Clay
+ * Nick Vlku
+ * martin
+ * Flavio Amieiro
+ * Анхбаяр Лхагвадорж
+ * Zak Johnson
+ * Victor Farazdagi
+ * vandersonmota
+ * Theo Julienne
+ * sp
+ * Slavi Pantaleev
+ * Richard Henry
+ * Nicolas Perriault
+ * Nick Vlku Jr
+ * Michael Henson
+ * Leo Honkanen
+ * kuno
+ * Josh Ourisman
+ * Jaime
+ * Igor Ivanov
+ * Gregg Lind
+ * Gareth Lloyd
+ * Albert Choi
+ * John Arnfield

MANIFEST.in

@@ -1,6 +1,6 @@
+include MANIFEST.in
 include README.rst
 include LICENSE
+include AUTHORS
 recursive-include docs *
-prune docs/_build/*
-recursive-include tests *
-recursive-exclude * *.pyc *.swp
+prune docs/_build

README.rst

@@ -15,7 +15,7 @@ a `tutorial <http://hmarr.com/mongoengine/tutorial.html>`_, a `user guide
 Installation
 ============
 If you have `setuptools <http://peak.telecommunity.com/DevCenter/setuptools>`_
-you can use ``easy_install mongoengine``. Otherwise, you can download the
+you can use ``easy_install -U mongoengine``. Otherwise, you can download the
 source from `GitHub <http://github.com/hmarr/mongoengine>`_ and run ``python
 setup.py install``.
 
@@ -82,6 +82,14 @@ Tests
 To run the test suite, ensure you are running a local instance of MongoDB on
 the standard port, and run ``python setup.py test``.
 
+Community
+=========
+- `MongoEngine Users mailing list 
+  <http://groups.google.com/group/mongoengine-users>`_
+- `MongoEngine Developers mailing list 
+  <http://groups.google.com/group/mongoengine-dev>`_
+- `#mongoengine IRC channel <irc://irc.freenode.net/mongoengine>`_
+
 Contributing
 ============
 The source is available on `GitHub <http://github.com/hmarr/mongoengine>`_ - to

docs/apireference.rst

@@ -15,12 +15,15 @@ Documents
 
    .. attribute:: objects
 
-      A :class:`~mongoengine.queryset.QuerySet` object that is created lazily 
+      A :class:`~mongoengine.queryset.QuerySet` object that is created lazily
       on access.
 
 .. autoclass:: mongoengine.EmbeddedDocument
    :members:
 
+.. autoclass:: mongoengine.document.MapReduceDocument
+  :members:
+
 Querying
 ========
 
@@ -28,26 +31,31 @@ Querying
    :members:
 
    .. automethod:: mongoengine.queryset.QuerySet.__call__
-   
+
 .. autofunction:: mongoengine.queryset.queryset_manager
 
 Fields
 ======
 
 .. autoclass:: mongoengine.StringField
-
+.. autoclass:: mongoengine.URLField
+.. autoclass:: mongoengine.EmailField
 .. autoclass:: mongoengine.IntField
-
 .. autoclass:: mongoengine.FloatField
-
-.. autoclass:: mongoengine.BooleanField
-
+.. autoclass:: mongoengine.DecimalField
 .. autoclass:: mongoengine.DateTimeField
-
-.. autoclass:: mongoengine.EmbeddedDocumentField
-
+.. autoclass:: mongoengine.ComplexDateTimeField
 .. autoclass:: mongoengine.ListField
-
+.. autoclass:: mongoengine.SortedListField
+.. autoclass:: mongoengine.DictField
+.. autoclass:: mongoengine.MapField
 .. autoclass:: mongoengine.ObjectIdField
-
 .. autoclass:: mongoengine.ReferenceField
+.. autoclass:: mongoengine.GenericReferenceField
+.. autoclass:: mongoengine.EmbeddedDocumentField
+.. autoclass:: mongoengine.GenericEmbeddedDocumentField
+.. autoclass:: mongoengine.BooleanField
+.. autoclass:: mongoengine.FileField
+.. autoclass:: mongoengine.BinaryField
+.. autoclass:: mongoengine.GeoPointField
+.. autoclass:: mongoengine.SequenceField

docs/changelog.rst

@@ -2,25 +2,163 @@
 Changelog
 =========
 
+Changes in v0.5.1
+=================
+
+- Circular reference bugfix
+
+Changes in v0.5
+===============
+
+- Added InvalidDocumentError - so Document core methods can't be overwritten
+- Added GenericEmbeddedDocument - so you can embed any type of embeddable document
+- Added within_polygon support - for those with mongodb 1.9
+- Updated sum / average to use map_reduce as db.eval doesn't work in sharded environments
+- Added where() - filter to allowing users to specify query expressions as Javascript
+- Added SequenceField - for creating sequential counters
+- Added update() convenience method to a document
+- Added cascading saves - so changes to Referenced documents are saved on .save()
+- Added select_related() support
+- Added support for the positional operator
+- Updated geo index checking to be recursive and check in embedded documents
+- Updated default collection naming convention
+- Added Document Mixin support
+- Fixed queryet __repr__ mid iteration
+- Added hint() support, so cantell Mongo the proper index to use for the query
+- Fixed issue with inconsitent setting of _cls breaking inherited referencing
+- Added help_text and verbose_name to fields to help with some form libs
+- Updated item_frequencies to handle embedded document lookups
+- Added delta tracking now only sets / unsets explicitly changed fields
+- Fixed saving so sets updated values rather than overwrites
+- Added ComplexDateTimeField - Handles datetimes correctly with microseconds
+- Added ComplexBaseField - for improved flexibility and performance
+- Added get_FIELD_display() method for easy choice field displaying
+- Added queryset.slave_okay(enabled) method
+- Updated queryset.timeout(enabled) and queryset.snapshot(enabled) to be chainable
+- Added insert method for bulk inserts
+- Added blinker signal support
+- Added query_counter context manager for tests
+- Added map_reduce method item_frequencies and set as default (as db.eval doesn't work in sharded environments)
+- Added inline_map_reduce option to map_reduce
+- Updated connection exception so it provides more info on the cause.
+- Added searching multiple levels deep in ``DictField``
+- Added ``DictField`` entries containing strings to use matching operators
+- Added ``MapField``, similar to ``DictField``
+- Added Abstract Base Classes
+- Added Custom Objects Managers
+- Added sliced subfields updating
+- Added ``NotRegistered`` exception if dereferencing ``Document`` not in the registry
+- Added a write concern for ``save``, ``update``, ``update_one`` and ``get_or_create``
+- Added slicing / subarray fetching controls
+- Fixed various unique index and other index issues
+- Fixed threaded connection issues
+- Added spherical geospatial query operators
+- Updated queryset to handle latest version of pymongo
+  map_reduce now requires an output.
+- Added ``Document`` __hash__, __ne__ for pickling
+- Added ``FileField`` optional size arg for read method
+- Fixed ``FileField`` seek and tell methods for reading files
+- Added ``QuerySet.clone`` to support copying querysets
+- Fixed item_frequencies when using name thats the same as a native js function
+- Added reverse delete rules
+- Fixed issue with unset operation
+- Fixed Q-object bug
+- Added ``QuerySet.all_fields`` resets previous .only() and .exclude()
+- Added ``QuerySet.exclude``
+- Added django style choices
+- Fixed order and filter issue
+- Added ``QuerySet.only`` subfield support
+- Added creation_counter to ``BaseField`` allowing fields to be sorted in the
+  way the user has specified them
+- Fixed various errors
+- Added many tests
+
+Changes in v0.4
+===============
+- Added ``GridFSStorage`` Django storage backend
+- Added ``FileField`` for GridFS support
+- New Q-object implementation, which is no longer based on Javascript
+- Added ``SortedListField``
+- Added ``EmailField``
+- Added ``GeoPointField``
+- Added ``exact`` and ``iexact`` match operators to ``QuerySet``
+- Added ``get_document_or_404`` and ``get_list_or_404`` Django shortcuts
+- Added new query operators for Geo queries
+- Added ``not`` query operator
+- Added new update operators: ``pop`` and ``add_to_set``
+- Added ``__raw__`` query parameter
+- Added support for custom querysets
+- Fixed document inheritance primary key issue
+- Added support for querying by array element position
+- Base class can now be defined for ``DictField``
+- Fixed MRO error that occured on document inheritance
+- Added ``QuerySet.distinct``, ``QuerySet.create``, ``QuerySet.snapshot``,
+  ``QuerySet.timeout`` and ``QuerySet.all``
+- Subsequent calls to ``connect()`` now work
+- Introduced ``min_length`` for ``StringField``
+- Fixed multi-process connection issue
+- Other minor fixes
+
+Changes in v0.3
+===============
+- Added MapReduce support
+- Added ``contains``, ``startswith`` and ``endswith`` query operators (and
+  case-insensitive versions that are prefixed with 'i')
+- Deprecated fields' ``name`` parameter, replaced with ``db_field``
+- Added ``QuerySet.only`` for only retrieving specific fields
+- Added ``QuerySet.in_bulk()`` for bulk querying using ids
+- ``QuerySet``\ s now have a ``rewind()`` method, which is called automatically
+  when the iterator is exhausted, allowing ``QuerySet``\ s to be reused
+- Added ``DictField``
+- Added ``URLField``
+- Added ``DecimalField``
+- Added ``BinaryField``
+- Added ``GenericReferenceField``
+- Added ``get()`` and ``get_or_create()`` methods to ``QuerySet``
+- ``ReferenceField``\ s may now reference the document they are defined on
+  (recursive references) and documents that have not yet been defined
+- ``Document`` objects may now be compared for equality (equal if _ids are
+  equal and documents are of same type)
+- ``QuerySet`` update methods now have an ``upsert`` parameter
+- Added field name substitution for Javascript code (allows the user to use the
+  Python names for fields in JS, which are later substituted for the real field
+  names)
+- ``Q`` objects now support regex querying
+- Fixed bug where referenced documents within lists weren't properly
+  dereferenced
+- ``ReferenceField``\ s may now be queried using their _id
+- Fixed bug where ``EmbeddedDocuments`` couldn't be non-polymorphic
+- ``queryset_manager`` functions now accept two arguments -- the document class
+  as the first and the queryset as the second
+- Fixed bug where ``QuerySet.exec_js`` ignored ``Q`` objects
+- Other minor fixes
+
+Changes in v0.2.2
+=================
+- Fixed bug that prevented indexes from being used on ``ListField``\ s
+- ``Document.filter()`` added as an alias to ``Document.__call__()``
+- ``validate()`` may now be used on ``EmbeddedDocument``\ s
+
 Changes in v0.2.1
 =================
 - Added a MongoEngine backend for Django sessions
-- Added force_insert to Document.save()
-- Improved querying syntax for ListField and EmbeddedDocumentField
-- Added support for user-defined primary keys (_ids in MongoDB)
+- Added ``force_insert`` to ``Document.save()``
+- Improved querying syntax for ``ListField`` and ``EmbeddedDocumentField``
+- Added support for user-defined primary keys (``_id`` in MongoDB)
 
 Changes in v0.2
 ===============
-- Added Q class for building advanced queries
-- Added QuerySet methods for atomic updates to documents
-- Fields may now specify ``unique=True`` to enforce uniqueness across a collection
+- Added ``Q`` class for building advanced queries
+- Added ``QuerySet`` methods for atomic updates to documents
+- Fields may now specify ``unique=True`` to enforce uniqueness across a
+  collection
 - Added option for default document ordering
 - Fixed bug in index definitions
 
 Changes in v0.1.3
 =================
 - Added Django authentication backend
-- Added Document.meta support for indexes, which are ensured just before 
+- Added ``Document.meta`` support for indexes, which are ensured just before
   querying takes place
 - A few minor bugfixes
 
@@ -30,8 +168,8 @@ Changes in v0.1.2
 - Query values may be processed before before being used in queries
 - Made connections lazy
 - Fixed bug in Document dictionary-style access
-- Added BooleanField
-- Added Document.reload method
+- Added ``BooleanField``
+- Added ``Document.reload()`` method
 
 
 Changes in v0.1.1

docs/conf.py

@@ -22,7 +22,7 @@ sys.path.append(os.path.abspath('..'))
 
 # Add any Sphinx extension module names here, as strings. They can be extensions
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
-extensions = ['sphinx.ext.autodoc']
+extensions = ['sphinx.ext.autodoc', 'sphinx.ext.todo']
 
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['_templates']
@@ -38,7 +38,7 @@ master_doc = 'index'
 
 # General information about the project.
 project = u'MongoEngine'
-copyright = u'2009, Harry Marr'
+copyright = u'2009-2011, Harry Marr'
 
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the

docs/django.rst

@@ -19,7 +19,7 @@ MongoDB but still use many of the Django authentication infrastucture (such as
 the :func:`login_required` decorator and the :func:`authenticate` function). To
 enable the MongoEngine auth backend, add the following to you **settings.py**
 file::
-    
+
     AUTHENTICATION_BACKENDS = (
         'mongoengine.django.auth.MongoEngineBackend',
     )
@@ -28,6 +28,8 @@ The :mod:`~mongoengine.django.auth` module also contains a
 :func:`~mongoengine.django.auth.get_user` helper function, that takes a user's
 :attr:`id` and returns a :class:`~mongoengine.django.auth.User` object.
 
+.. versionadded:: 0.1.3
+
 Sessions
 ========
 Django allows the use of different backend stores for its sessions. MongoEngine
@@ -40,3 +42,47 @@ session backend, ensure that your settings module has
 into you settings module::
 
     SESSION_ENGINE = 'mongoengine.django.sessions'
+
+.. versionadded:: 0.2.1
+
+Storage
+=======
+With MongoEngine's support for GridFS via the :class:`~mongoengine.FileField`,
+it is useful to have a Django file storage backend that wraps this. The new
+storage module is called :class:`~mongoengine.django.storage.GridFSStorage`. 
+Using it is very similar to using the default FileSystemStorage.::
+    
+    from mongoengine.django.storage import GridFSStorage
+    fs = GridFSStorage()
+
+    filename = fs.save('hello.txt', 'Hello, World!')
+
+All of the `Django Storage API methods
+<http://docs.djangoproject.com/en/dev/ref/files/storage/>`_ have been
+implemented except :func:`path`. If the filename provided already exists, an
+underscore and a number (before # the file extension, if one exists) will be
+appended to the filename until the generated filename doesn't exist. The
+:func:`save` method will return the new filename.::
+
+    >>> fs.exists('hello.txt')
+    True
+    >>> fs.open('hello.txt').read()
+    'Hello, World!'
+    >>> fs.size('hello.txt')
+    13
+    >>> fs.url('hello.txt')
+    'http://your_media_url/hello.txt'
+    >>> fs.open('hello.txt').name
+    'hello.txt'
+    >>> fs.listdir()
+    ([], [u'hello.txt'])
+
+All files will be saved and retrieved in GridFS via the :class::`FileDocument`
+document, allowing easy access to the files without the GridFSStorage
+backend.::
+
+    >>> from mongoengine.django.storage import FileDocument
+    >>> FileDocument.objects()
+    [<FileDocument: FileDocument object>]
+
+.. versionadded:: 0.4

docs/guide/connecting.rst

@@ -0,0 +1,20 @@
+.. _guide-connecting:
+
+=====================
+Connecting to MongoDB
+=====================
+To connect to a running instance of :program:`mongod`, use the
+:func:`~mongoengine.connect` function. The first argument is the name of the
+database to connect to. If the database does not exist, it will be created. If
+the database requires authentication, :attr:`username` and :attr:`password`
+arguments may be provided::
+
+    from mongoengine import connect
+    connect('project1', username='webapp', password='pwd123')
+
+By default, MongoEngine assumes that the :program:`mongod` instance is running
+on **localhost** on port **27017**. If MongoDB is running elsewhere, you may
+provide :attr:`host` and :attr:`port` arguments to
+:func:`~mongoengine.connect`::
+
+    connect('project1', host='192.168.1.35', port=12345)

docs/guide/defining-documents.rst

@@ -0,0 +1,465 @@
+==================
+Defining documents
+==================
+In MongoDB, a **document** is roughly equivalent to a **row** in an RDBMS. When
+working with relational databases, rows are stored in **tables**, which have a
+strict **schema** that the rows follow. MongoDB stores documents in
+**collections** rather than tables - the principle difference is that no schema
+is enforced at a database level.
+
+Defining a document's schema
+============================
+MongoEngine allows you to define schemata for documents as this helps to reduce
+coding errors, and allows for utility methods to be defined on fields which may
+be present.
+
+To define a schema for a document, create a class that inherits from
+:class:`~mongoengine.Document`. Fields are specified by adding **field
+objects** as class attributes to the document class::
+
+    from mongoengine import *
+    import datetime
+
+    class Page(Document):
+        title = StringField(max_length=200, required=True)
+        date_modified = DateTimeField(default=datetime.datetime.now)
+
+Fields
+======
+By default, fields are not required. To make a field mandatory, set the
+:attr:`required` keyword argument of a field to ``True``. Fields also may have
+validation constraints available (such as :attr:`max_length` in the example
+above). Fields may also take default values, which will be used if a value is
+not provided. Default values may optionally be a callable, which will be called
+to retrieve the value (such as in the above example). The field types available
+are as follows:
+
+* :class:`~mongoengine.StringField`
+* :class:`~mongoengine.URLField`
+* :class:`~mongoengine.EmailField`
+* :class:`~mongoengine.IntField`
+* :class:`~mongoengine.FloatField`
+* :class:`~mongoengine.DecimalField`
+* :class:`~mongoengine.DateTimeField`
+* :class:`~mongoengine.ComplexDateTimeField`
+* :class:`~mongoengine.ListField`
+* :class:`~mongoengine.SortedListField`
+* :class:`~mongoengine.DictField`
+* :class:`~mongoengine.MapField`
+* :class:`~mongoengine.ObjectIdField`
+* :class:`~mongoengine.ReferenceField`
+* :class:`~mongoengine.GenericReferenceField`
+* :class:`~mongoengine.EmbeddedDocumentField`
+* :class:`~mongoengine.GenericEmbeddedDocumentField`
+* :class:`~mongoengine.BooleanField`
+* :class:`~mongoengine.FileField`
+* :class:`~mongoengine.BinaryField`
+* :class:`~mongoengine.GeoPointField`
+* :class:`~mongoengine.SequenceField`
+
+Field arguments
+---------------
+Each field type can be customized by keyword arguments.  The following keyword
+arguments can be set on all fields:
+
+:attr:`db_field` (Default: None)
+    The MongoDB field name.
+
+:attr:`name` (Default: None)
+    The mongoengine field name.
+
+:attr:`required` (Default: False)
+    If set to True and the field is not set on the document instance, a
+    :class:`~mongoengine.base.ValidationError` will be raised when the document is
+    validated.
+
+:attr:`default` (Default: None)
+    A value to use when no value is set for this field.
+
+    The definion of default parameters follow `the general rules on Python
+    <http://docs.python.org/reference/compound_stmts.html#function-definitions>`__,
+    which means that some care should be taken when dealing with default mutable objects
+    (like in :class:`~mongoengine.ListField` or :class:`~mongoengine.DictField`)::
+
+        class ExampleFirst(Document):
+            # Default an empty list
+            values = ListField(IntField(), default=list)
+
+        class ExampleSecond(Document):
+            # Default a set of values
+            values = ListField(IntField(), default=lambda: [1,2,3])
+
+        class ExampleDangerous(Document):
+            # This can make an .append call to  add values to the default (and all the following objects),
+            # instead to just an object
+            values = ListField(IntField(), default=[1,2,3])
+
+
+:attr:`unique` (Default: False)
+    When True, no documents in the collection will have the same value for this
+    field.
+
+:attr:`unique_with` (Default: None)
+    A field name (or list of field names) that when taken together with this
+    field, will not have two documents in the collection with the same value.
+
+:attr:`primary_key` (Default: False)
+    When True, use this field as a primary key for the collection.
+
+:attr:`choices` (Default: None)
+    An iterable of choices to which the value of this field should be limited.
+
+:attr:`help_text` (Default: None)
+    Optional help text to output with the field - used by form libraries
+
+:attr:`verbose` (Default: None)
+    Optional human-readable name for the field - used by form libraries
+
+
+List fields
+-----------
+MongoDB allows the storage of lists of items. To add a list of items to a
+:class:`~mongoengine.Document`, use the :class:`~mongoengine.ListField` field
+type. :class:`~mongoengine.ListField` takes another field object as its first
+argument, which specifies which type elements may be stored within the list::
+
+    class Page(Document):
+        tags = ListField(StringField(max_length=50))
+
+Embedded documents
+------------------
+MongoDB has the ability to embed documents within other documents. Schemata may
+be defined for these embedded documents, just as they may be for regular
+documents. To create an embedded document, just define a document as usual, but
+inherit from :class:`~mongoengine.EmbeddedDocument` rather than
+:class:`~mongoengine.Document`::
+
+    class Comment(EmbeddedDocument):
+        content = StringField()
+
+To embed the document within another document, use the
+:class:`~mongoengine.EmbeddedDocumentField` field type, providing the embedded
+document class as the first argument::
+
+    class Page(Document):
+        comments = ListField(EmbeddedDocumentField(Comment))
+
+    comment1 = Comment(content='Good work!')
+    comment2 = Comment(content='Nice article!')
+    page = Page(comments=[comment1, comment2])
+
+Dictionary Fields
+-----------------
+Often, an embedded document may be used instead of a dictionary -- generally
+this is recommended as dictionaries don't support validation or custom field
+types. However, sometimes you will not know the structure of what you want to
+store; in this situation a :class:`~mongoengine.DictField` is appropriate::
+
+    class SurveyResponse(Document):
+        date = DateTimeField()
+        user = ReferenceField(User)
+        answers = DictField()
+
+    survey_response = SurveyResponse(date=datetime.now(), user=request.user)
+    response_form = ResponseForm(request.POST)
+    survey_response.answers = response_form.cleaned_data()
+    survey_response.save()
+
+Dictionaries can store complex data, other dictionaries, lists, references to
+other objects, so are the most flexible field type available.
+
+Reference fields
+----------------
+References may be stored to other documents in the database using the
+:class:`~mongoengine.ReferenceField`. Pass in another document class as the
+first argument to the constructor, then simply assign document objects to the
+field::
+
+    class User(Document):
+        name = StringField()
+
+    class Page(Document):
+        content = StringField()
+        author = ReferenceField(User)
+
+    john = User(name="John Smith")
+    john.save()
+
+    post = Page(content="Test Page")
+    post.author = john
+    post.save()
+
+The :class:`User` object is automatically turned into a reference behind the
+scenes, and dereferenced when the :class:`Page` object is retrieved.
+
+To add a :class:`~mongoengine.ReferenceField` that references the document
+being defined, use the string ``'self'`` in place of the document class as the
+argument to :class:`~mongoengine.ReferenceField`'s constructor. To reference a
+document that has not yet been defined, use the name of the undefined document
+as the constructor's argument::
+
+    class Employee(Document):
+        name = StringField()
+        boss = ReferenceField('self')
+        profile_page = ReferenceField('ProfilePage')
+
+    class ProfilePage(Document):
+        content = StringField()
+
+
+Dealing with deletion of referred documents
+'''''''''''''''''''''''''''''''''''''''''''
+By default, MongoDB doesn't check the integrity of your data, so deleting
+documents that other documents still hold references to will lead to consistency
+issues.  Mongoengine's :class:`ReferenceField` adds some functionality to
+safeguard against these kinds of database integrity problems, providing each
+reference with a delete rule specification.  A delete rule is specified by
+supplying the :attr:`reverse_delete_rule` attributes on the
+:class:`ReferenceField` definition, like this::
+
+    class Employee(Document):
+        ...
+        profile_page = ReferenceField('ProfilePage', reverse_delete_rule=mongoengine.NULLIFY)
+
+The declaration in this example means that when an :class:`Employee` object is
+removed, the :class:`ProfilePage` that belongs to that employee is removed as
+well.  If a whole batch of employees is removed, all profile pages that are
+linked are removed as well.
+
+Its value can take any of the following constants:
+
+:const:`mongoengine.DO_NOTHING`
+  This is the default and won't do anything.  Deletes are fast, but may cause
+  database inconsistency or dangling references.
+:const:`mongoengine.DENY`
+  Deletion is denied if there still exist references to the object being
+  deleted.
+:const:`mongoengine.NULLIFY`
+  Any object's fields still referring to the object being deleted are removed
+  (using MongoDB's "unset" operation), effectively nullifying the relationship.
+:const:`mongoengine.CASCADE`
+  Any object containing fields that are refererring to the object being deleted
+  are deleted first.
+
+
+.. warning::
+   A safety note on setting up these delete rules!  Since the delete rules are
+   not recorded on the database level by MongoDB itself, but instead at runtime,
+   in-memory, by the MongoEngine module, it is of the upmost importance
+   that the module that declares the relationship is loaded **BEFORE** the
+   delete is invoked.
+
+   If, for example, the :class:`Employee` object lives in the
+   :mod:`payroll` app, and the :class:`ProfilePage` in the :mod:`people`
+   app, it is extremely important that the :mod:`people` app is loaded
+   before any employee is removed, because otherwise, MongoEngine could
+   never know this relationship exists.
+
+   In Django, be sure to put all apps that have such delete rule declarations in
+   their :file:`models.py` in the :const:`INSTALLED_APPS` tuple.
+
+
+Generic reference fields
+''''''''''''''''''''''''
+A second kind of reference field also exists,
+:class:`~mongoengine.GenericReferenceField`. This allows you to reference any
+kind of :class:`~mongoengine.Document`, and hence doesn't take a
+:class:`~mongoengine.Document` subclass as a constructor argument::
+
+    class Link(Document):
+        url = StringField()
+
+    class Post(Document):
+        title = StringField()
+
+    class Bookmark(Document):
+        bookmark_object = GenericReferenceField()
+
+    link = Link(url='http://hmarr.com/mongoengine/')
+    link.save()
+
+    post = Post(title='Using MongoEngine')
+    post.save()
+
+    Bookmark(bookmark_object=link).save()
+    Bookmark(bookmark_object=post).save()
+
+.. note::
+
+   Using :class:`~mongoengine.GenericReferenceField`\ s is slightly less
+   efficient than the standard :class:`~mongoengine.ReferenceField`\ s, so if
+   you will only be referencing one document type, prefer the standard
+   :class:`~mongoengine.ReferenceField`.
+
+Uniqueness constraints
+----------------------
+MongoEngine allows you to specify that a field should be unique across a
+collection by providing ``unique=True`` to a :class:`~mongoengine.Field`\ 's
+constructor. If you try to save a document that has the same value for a unique
+field as a document that is already in the database, a
+:class:`~mongoengine.OperationError` will be raised. You may also specify
+multi-field uniqueness constraints by using :attr:`unique_with`, which may be
+either a single field name, or a list or tuple of field names::
+
+    class User(Document):
+        username = StringField(unique=True)
+        first_name = StringField()
+        last_name = StringField(unique_with='first_name')
+
+Skipping Document validation on save
+------------------------------------
+You can also skip the whole document validation process by setting
+``validate=False`` when caling the :meth:`~mongoengine.document.Document.save`
+method::
+
+    class Recipient(Document):
+        name = StringField()
+        email = EmailField()
+
+    recipient = Recipient(name='admin', email='root@localhost')
+    recipient.save()               # will raise a ValidationError while
+    recipient.save(validate=False) # won't
+
+Document collections
+====================
+Document classes that inherit **directly** from :class:`~mongoengine.Document`
+will have their own **collection** in the database. The name of the collection
+is by default the name of the class, coverted to lowercase (so in the example
+above, the collection would be called `page`). If you need to change the name
+of the collection (e.g. to use MongoEngine with an existing database), then
+create a class dictionary attribute called :attr:`meta` on your document, and
+set :attr:`collection` to the name of the collection that you want your
+document class to use::
+
+    class Page(Document):
+        title = StringField(max_length=200, required=True)
+        meta = {'collection': 'cmsPage'}
+
+Capped collections
+------------------
+A :class:`~mongoengine.Document` may use a **Capped Collection** by specifying
+:attr:`max_documents` and :attr:`max_size` in the :attr:`meta` dictionary.
+:attr:`max_documents` is the maximum number of documents that is allowed to be
+stored in the collection, and :attr:`max_size` is the maximum size of the
+collection in bytes. If :attr:`max_size` is not specified and
+:attr:`max_documents` is, :attr:`max_size` defaults to 10000000 bytes (10MB).
+The following example shows a :class:`Log` document that will be limited to
+1000 entries and 2MB of disk space::
+
+    class Log(Document):
+        ip_address = StringField()
+        meta = {'max_documents': 1000, 'max_size': 2000000}
+
+Indexes
+=======
+You can specify indexes on collections to make querying faster. This is done
+by creating a list of index specifications called :attr:`indexes` in the
+:attr:`~mongoengine.Document.meta` dictionary, where an index specification may
+either be a single field name, a tuple containing multiple field names, or a
+dictionary containing a full index definition. A direction may be specified on
+fields by prefixing the field name with a **+** or a **-** sign. Note that
+direction only matters on multi-field indexes. ::
+
+    class Page(Document):
+        title = StringField()
+        rating = StringField()
+        meta = {
+            'indexes': ['title', ('title', '-rating')]
+        }
+
+If a dictionary is passed then the following options are available:
+
+:attr:`fields` (Default: None)
+    The fields to index. Specified in the same format as described above.
+
+:attr:`types` (Default: True)
+    Whether the index should have the :attr:`_types` field added automatically
+    to the start of the index.
+
+:attr:`sparse` (Default: False)
+    Whether the index should be sparse.
+
+:attr:`unique` (Default: False)
+    Whether the index should be sparse.
+
+.. note::
+
+   Geospatial indexes will be automatically created for all
+   :class:`~mongoengine.GeoPointField`\ s
+
+Ordering
+========
+A default ordering can be specified for your
+:class:`~mongoengine.queryset.QuerySet` using the :attr:`ordering` attribute of
+:attr:`~mongoengine.Document.meta`.  Ordering will be applied when the
+:class:`~mongoengine.queryset.QuerySet` is created, and can be overridden by
+subsequent calls to :meth:`~mongoengine.queryset.QuerySet.order_by`. ::
+
+    from datetime import datetime
+
+    class BlogPost(Document):
+        title = StringField()
+        published_date = DateTimeField()
+
+        meta = {
+            'ordering': ['-published_date']
+        }
+
+    blog_post_1 = BlogPost(title="Blog Post #1")
+    blog_post_1.published_date = datetime(2010, 1, 5, 0, 0 ,0)
+
+    blog_post_2 = BlogPost(title="Blog Post #2")
+    blog_post_2.published_date = datetime(2010, 1, 6, 0, 0 ,0)
+
+    blog_post_3 = BlogPost(title="Blog Post #3")
+    blog_post_3.published_date = datetime(2010, 1, 7, 0, 0 ,0)
+
+    blog_post_1.save()
+    blog_post_2.save()
+    blog_post_3.save()
+
+    # get the "first" BlogPost using default ordering
+    # from BlogPost.meta.ordering
+    latest_post = BlogPost.objects.first()
+    assert latest_post.title == "Blog Post #3"
+
+    # override default ordering, order BlogPosts by "published_date"
+    first_post = BlogPost.objects.order_by("+published_date").first()
+    assert first_post.title == "Blog Post #1"
+
+Document inheritance
+====================
+To create a specialised type of a :class:`~mongoengine.Document` you have
+defined, you may subclass it and add any extra fields or methods you may need.
+As this is new class is not a direct subclass of
+:class:`~mongoengine.Document`, it will not be stored in its own collection; it
+will use the same collection as its superclass uses. This allows for more
+convenient and efficient retrieval of related documents::
+
+    # Stored in a collection named 'page'
+    class Page(Document):
+        title = StringField(max_length=200, required=True)
+
+    # Also stored in the collection named 'page'
+    class DatedPage(Page):
+        date = DateTimeField()
+
+Working with existing data
+--------------------------
+To enable correct retrieval of documents involved in this kind of heirarchy,
+two extra attributes are stored on each document in the database: :attr:`_cls`
+and :attr:`_types`. These are hidden from the user through the MongoEngine
+interface, but may not be present if you are trying to use MongoEngine with
+an existing database. For this reason, you may disable this inheritance
+mechansim, removing the dependency of :attr:`_cls` and :attr:`_types`, enabling
+you to work with existing databases. To disable inheritance on a document
+class, set :attr:`allow_inheritance` to ``False`` in the :attr:`meta`
+dictionary::
+
+    # Will work with data in an existing collection named 'cmsPage'
+    class Page(Document):
+        title = StringField(max_length=200, required=True)
+        meta = {
+            'collection': 'cmsPage',
+            'allow_inheritance': False,
+        }

docs/guide/document-instances.rst

@@ -0,0 +1,85 @@
+===================
+Documents instances
+===================
+To create a new document object, create an instance of the relevant document
+class, providing values for its fields as its constructor keyword arguments.
+You may provide values for any of the fields on the document::
+
+    >>> page = Page(title="Test Page")
+    >>> page.title
+    'Test Page'
+
+You may also assign values to the document's fields using standard object
+attribute syntax::
+
+    >>> page.title = "Example Page"
+    >>> page.title
+    'Example Page'
+
+Saving and deleting documents
+=============================
+MongoEngine tracks changes to documents to provide efficient saving.  To save
+the document to the database, call the :meth:`~mongoengine.Document.save` method.
+If the document does not exist in the database, it will be created. If it does
+already exist, then any changes will be updated atomically.  For example::
+
+    >>> page = Page(title="Test Page")
+    >>> page.save()  # Performs an insert
+    >>> page.title = "My Page"
+    >>> page.save()  # Performs an atomic set on the title field.
+
+.. note::
+
+    Changes to documents are tracked and on the whole perform `set` operations.
+
+    * ``list_field.pop(0)`` - *sets* the resulting list
+    * ``del(list_field)``   - *unsets* whole list
+
+To delete a document, call the :meth:`~mongoengine.Document.delete` method.
+Note that this will only work if the document exists in the database and has a
+valide :attr:`id`.
+
+.. seealso::
+    :ref:`guide-atomic-updates`
+
+Document IDs
+============
+Each document in the database has a unique id. This may be accessed through the
+:attr:`id` attribute on :class:`~mongoengine.Document` objects. Usually, the id
+will be generated automatically by the database server when the object is save,
+meaning that you may only access the :attr:`id` field once a document has been
+saved::
+
+    >>> page = Page(title="Test Page")
+    >>> page.id
+    >>> page.save()
+    >>> page.id
+    ObjectId('123456789abcdef000000000')
+
+Alternatively, you may define one of your own fields to be the document's
+"primary key" by providing ``primary_key=True`` as a keyword argument to a
+field's constructor. Under the hood, MongoEngine will use this field as the
+:attr:`id`; in fact :attr:`id` is actually aliased to your primary key field so
+you may still use :attr:`id` to access the primary key if you want::
+
+    >>> class User(Document):
+    ...     email = StringField(primary_key=True)
+    ...     name = StringField()
+    ...
+    >>> bob = User(email='bob@example.com', name='Bob')
+    >>> bob.save()
+    >>> bob.id == bob.email == 'bob@example.com'
+    True
+
+You can also access the document's "primary key" using the :attr:`pk` field; in
+is an alias to :attr:`id`::
+
+    >>> page = Page(title="Another Test Page")
+    >>> page.save()
+    >>> page.id == page.pk
+
+.. note::
+
+   If you define your own primary key field, the field implicitly becomes
+   required, so a :class:`ValidationError` will be thrown if you don't provide
+   it.

docs/guide/gridfs.rst

@@ -0,0 +1,84 @@
+======
+GridFS
+======
+
+.. versionadded:: 0.4
+
+Writing
+-------
+
+GridFS support comes in the form of the :class:`~mongoengine.FileField` field
+object. This field acts as a file-like object and provides a couple of
+different ways of inserting and retrieving data. Arbitrary metadata such as
+content type can also be stored alongside the files. In the following example,
+a document is created to store details about animals, including a photo::
+
+    class Animal(Document):
+        genus = StringField()
+        family = StringField()
+        photo = FileField()
+
+    marmot = Animal('Marmota', 'Sciuridae')
+
+    marmot_photo = open('marmot.jpg', 'r')      # Retrieve a photo from disk
+    marmot.photo = marmot_photo                 # Store photo in the document
+    marmot.photo.content_type = 'image/jpeg'    # Store metadata
+
+    marmot.save()
+
+Another way of writing to a :class:`~mongoengine.FileField` is to use the
+:func:`put` method. This allows for metadata to be stored in the same call as
+the file::
+
+    marmot.photo.put(marmot_photo, content_type='image/jpeg')
+
+    marmot.save()
+
+Retrieval
+---------
+
+So using the :class:`~mongoengine.FileField` is just like using any other
+field. The file can also be retrieved just as easily::
+
+    marmot = Animal.objects(genus='Marmota').first()
+    photo = marmot.photo.read()
+    content_type = marmot.photo.content_type
+
+Streaming
+---------
+
+Streaming data into a :class:`~mongoengine.FileField` is achieved in a
+slightly different manner.  First, a new file must be created by calling the
+:func:`new_file` method. Data can then be written using :func:`write`::
+
+    marmot.photo.new_file()
+    marmot.photo.write('some_image_data')
+    marmot.photo.write('some_more_image_data')
+    marmot.photo.close()
+
+    marmot.photo.save()
+
+Deletion
+--------
+
+Deleting stored files is achieved with the :func:`delete` method::
+
+    marmot.photo.delete()
+
+.. note::
+
+    The FileField in a Document actually only stores the ID of a file in a
+    separate GridFS collection. This means that deleting a document
+    with a defined FileField does not actually delete the file. You must be
+    careful to delete any files in a Document as above before deleting the
+    Document itself.
+
+
+Replacing files
+---------------
+
+Files can be replaced with the :func:`replace` method. This works just like
+the :func:`put` method so even metadata can (and should) be replaced::
+
+    another_marmot = open('another_marmot.png', 'r')
+    marmot.photo.replace(another_marmot, content_type='image/png')

docs/guide/index.rst

@@ -0,0 +1,14 @@
+==========
+User Guide
+==========
+
+.. toctree::
+   :maxdepth: 2
+
+   installing
+   connecting
+   defining-documents
+   document-instances
+   querying
+   gridfs
+   signals

docs/guide/installing.rst

@@ -0,0 +1,31 @@
+======================
+Installing MongoEngine
+======================
+
+To use MongoEngine, you will need to download `MongoDB <http://mongodb.org/>`_
+and ensure it is running in an accessible location. You will also need
+`PyMongo <http://api.mongodb.org/python>`_ to use MongoEngine, but if you
+install MongoEngine using setuptools, then the dependencies will be handled for
+you.
+
+MongoEngine is available on PyPI, so to use it you can use :program:`pip`:
+
+.. code-block:: console
+
+    $ pip install mongoengine
+
+Alternatively, if you don't have setuptools installed, `download it from PyPi
+<http://pypi.python.org/pypi/mongoengine/>`_ and run
+
+.. code-block:: console
+
+    $ python setup.py install
+
+To use the bleeding-edge version of MongoEngine, you can get the source from
+`GitHub <http://github.com/hmarr/mongoengine/>`_ and install it as above:
+
+.. code-block:: console
+
+    $ git clone git://github.com/hmarr/mongoengine
+    $ cd mongoengine
+    $ python setup.py install

docs/guide/querying.rst

@@ -0,0 +1,531 @@
+=====================
+Querying the database
+=====================
+:class:`~mongoengine.Document` classes have an :attr:`objects` attribute, which
+is used for accessing the objects in the database associated with the class.
+The :attr:`objects` attribute is actually a
+:class:`~mongoengine.queryset.QuerySetManager`, which creates and returns a new
+:class:`~mongoengine.queryset.QuerySet` object on access. The
+:class:`~mongoengine.queryset.QuerySet` object may be iterated over to
+fetch documents from the database::
+
+    # Prints out the names of all the users in the database
+    for user in User.objects:
+        print user.name
+
+.. note::
+
+   Once the iteration finishes (when :class:`StopIteration` is raised),
+   :meth:`~mongoengine.queryset.QuerySet.rewind` will be called so that the
+   :class:`~mongoengine.queryset.QuerySet` may be iterated over again. The
+   results of the first iteration are *not* cached, so the database will be hit
+   each time the :class:`~mongoengine.queryset.QuerySet` is iterated over.
+
+Filtering queries
+=================
+The query may be filtered by calling the
+:class:`~mongoengine.queryset.QuerySet` object with field lookup keyword
+arguments. The keys in the keyword arguments correspond to fields on the
+:class:`~mongoengine.Document` you are querying::
+
+    # This will return a QuerySet that will only iterate over users whose
+    # 'country' field is set to 'uk'
+    uk_users = User.objects(country='uk')
+
+Fields on embedded documents may also be referred to using field lookup syntax
+by using a double-underscore in place of the dot in object attribute access
+syntax::
+
+    # This will return a QuerySet that will only iterate over pages that have
+    # been written by a user whose 'country' field is set to 'uk'
+    uk_pages = Page.objects(author__country='uk')
+
+
+Query operators
+===============
+Operators other than equality may also be used in queries; just attach the
+operator name to a key with a double-underscore::
+
+    # Only find users whose age is 18 or less
+    young_users = Users.objects(age__lte=18)
+
+Available operators are as follows:
+
+* ``ne`` -- not equal to
+* ``lt`` -- less than
+* ``lte`` -- less than or equal to
+* ``gt`` -- greater than
+* ``gte`` -- greater than or equal to
+* ``not`` -- negate a standard check, may be used before other operators (e.g.
+  ``Q(age__not__mod=5)``)
+* ``in`` -- value is in list (a list of values should be provided)
+* ``nin`` -- value is not in list (a list of values should be provided)
+* ``mod`` -- ``value % x == y``, where ``x`` and ``y`` are two provided values
+* ``all`` -- every item in list of values provided is in array
+* ``size`` -- the size of the array is
+* ``exists`` -- value for field exists
+
+The following operators are available as shortcuts to querying with regular
+expressions:
+
+* ``exact`` -- string field exactly matches value
+* ``iexact`` -- string field exactly matches value (case insensitive)
+* ``contains`` -- string field contains value
+* ``icontains`` -- string field contains value (case insensitive)
+* ``startswith`` -- string field starts with value
+* ``istartswith`` -- string field starts with value (case insensitive)
+* ``endswith`` -- string field ends with value
+* ``iendswith`` -- string field ends with value (case insensitive)
+
+There are a few special operators for performing geographical queries, that
+may used with :class:`~mongoengine.GeoPointField`\ s:
+
+* ``within_distance`` -- provide a list containing a point and a maximum
+  distance (e.g. [(41.342, -87.653), 5])
+* ``within_spherical_distance`` -- Same as above but using the spherical geo model
+  (e.g. [(41.342, -87.653), 5/earth_radius])
+* ``near`` -- order the documents by how close they are to a given point
+* ``near_sphere`` -- Same as above but using the spherical geo model
+* ``within_box`` -- filter documents to those within a given bounding box (e.g.
+  [(35.0, -125.0), (40.0, -100.0)])
+* ``within_polygon`` -- filter documents to those within a given polygon (e.g.
+  [(41.91,-87.69), (41.92,-87.68), (41.91,-87.65), (41.89,-87.65)]).
+  .. note:: Requires Mongo Server 2.0
+
+
+Querying lists
+--------------
+On most fields, this syntax will look up documents where the field specified
+matches the given value exactly, but when the field refers to a
+:class:`~mongoengine.ListField`, a single item may be provided, in which case
+lists that contain that item will be matched::
+
+    class Page(Document):
+        tags = ListField(StringField())
+
+    # This will match all pages that have the word 'coding' as an item in the
+    # 'tags' list
+    Page.objects(tags='coding')
+
+It is possible to query by position in a list by using a numerical value as a
+query operator. So if you wanted to find all pages whose first tag was ``db``,
+you could use the following query::
+
+    Page.objects(tags__0='db')
+
+If you only want to fetch part of a list eg: you want to paginate a list, then
+the `slice` operator is required::
+
+    # comments - skip 5, limit 10
+    Page.objects.fields(slice__comments=[5, 10])
+
+For updating documents, if you don't know the position in a list, you can use
+the $ positional operator ::
+
+    Post.objects(comments__by="joe").update(**{'inc__comments__$__votes': 1})
+
+However, this doesn't map well to the syntax so you can also use a capital S instead ::
+
+    Post.objects(comments__by="joe").update(inc__comments__S__votes=1)
+
+    .. note:: Due to Mongo currently the $ operator only applies to the first matched item in the query.
+
+
+Raw queries
+-----------
+It is possible to provide a raw PyMongo query as a query parameter, which will
+be integrated directly into the query. This is done using the ``__raw__``
+keyword argument::
+
+    Page.objects(__raw__={'tags': 'coding'})
+
+.. versionadded:: 0.4
+
+Limiting and skipping results
+=============================
+Just as with traditional ORMs, you may limit the number of results returned, or
+skip a number or results in you query.
+:meth:`~mongoengine.queryset.QuerySet.limit` and
+:meth:`~mongoengine.queryset.QuerySet.skip` and methods are available on
+:class:`~mongoengine.queryset.QuerySet` objects, but the prefered syntax for
+achieving this is using array-slicing syntax::
+
+    # Only the first 5 people
+    users = User.objects[:5]
+
+    # All except for the first 5 people
+    users = User.objects[5:]
+
+    # 5 users, starting from the 10th user found
+    users = User.objects[10:15]
+
+You may also index the query to retrieve a single result. If an item at that
+index does not exists, an :class:`IndexError` will be raised. A shortcut for
+retrieving the first result and returning :attr:`None` if no result exists is
+provided (:meth:`~mongoengine.queryset.QuerySet.first`)::
+
+    >>> # Make sure there are no users
+    >>> User.drop_collection()
+    >>> User.objects[0]
+    IndexError: list index out of range
+    >>> User.objects.first() == None
+    True
+    >>> User(name='Test User').save()
+    >>> User.objects[0] == User.objects.first()
+    True
+
+Retrieving unique results
+-------------------------
+To retrieve a result that should be unique in the collection, use
+:meth:`~mongoengine.queryset.QuerySet.get`. This will raise
+:class:`~mongoengine.queryset.DoesNotExist` if no document matches the query,
+and :class:`~mongoengine.queryset.MultipleObjectsReturned` if more than one
+document matched the query.
+
+A variation of this method exists,
+:meth:`~mongoengine.queryset.Queryset.get_or_create`, that will create a new
+document with the query arguments if no documents match the query. An
+additional keyword argument, :attr:`defaults` may be provided, which will be
+used as default values for the new document, in the case that it should need
+to be created::
+
+    >>> a, created = User.objects.get_or_create(name='User A', defaults={'age': 30})
+    >>> b, created = User.objects.get_or_create(name='User A', defaults={'age': 40})
+    >>> a.name == b.name and a.age == b.age
+    True
+
+Dereferencing results
+---------------------
+When iterating the results of :class:`~mongoengine.ListField` or
+:class:`~mongoengine.DictField` we automatically dereference any
+:class:`~pymongo.dbref.DBRef` objects as efficiently as possible, reducing the
+number the queries to mongo.
+
+There are times when that efficiency is not enough, documents that have
+:class:`~mongoengine.ReferenceField` objects or
+:class:`~mongoengine.GenericReferenceField` objects at the top level are
+expensive as the number of queries to MongoDB can quickly rise.
+
+To limit the number of queries use
+:func:`~mongoengine.queryset.QuerySet.select_related` which converts the
+QuerySet to a list and dereferences as efficiently as possible.
+
+Default Document queries
+========================
+By default, the objects :attr:`~mongoengine.Document.objects` attribute on a
+document returns a :class:`~mongoengine.queryset.QuerySet` that doesn't filter
+the collection -- it returns all objects. This may be changed by defining a
+method on a document that modifies a queryset. The method should accept two
+arguments -- :attr:`doc_cls` and :attr:`queryset`. The first argument is the
+:class:`~mongoengine.Document` class that the method is defined on (in this
+sense, the method is more like a :func:`classmethod` than a regular method),
+and the second argument is the initial queryset. The method needs to be
+decorated with :func:`~mongoengine.queryset.queryset_manager` in order for it
+to be recognised. ::
+
+    class BlogPost(Document):
+        title = StringField()
+        date = DateTimeField()
+
+        @queryset_manager
+        def objects(doc_cls, queryset):
+            # This may actually also be done by defining a default ordering for
+            # the document, but this illustrates the use of manager methods
+            return queryset.order_by('-date')
+
+You don't need to call your method :attr:`objects` -- you may define as many
+custom manager methods as you like::
+
+    class BlogPost(Document):
+        title = StringField()
+        published = BooleanField()
+
+        @queryset_manager
+        def live_posts(doc_cls, queryset):
+            return queryset.filter(published=True)
+
+    BlogPost(title='test1', published=False).save()
+    BlogPost(title='test2', published=True).save()
+    assert len(BlogPost.objects) == 2
+    assert len(BlogPost.live_posts) == 1
+
+Custom QuerySets
+================
+Should you want to add custom methods for interacting with or filtering
+documents, extending the :class:`~mongoengine.queryset.QuerySet` class may be
+the way to go. To use a custom :class:`~mongoengine.queryset.QuerySet` class on
+a document, set ``queryset_class`` to the custom class in a
+:class:`~mongoengine.Document`\ s ``meta`` dictionary::
+
+    class AwesomerQuerySet(QuerySet):
+        pass
+
+    class Page(Document):
+        meta = {'queryset_class': AwesomerQuerySet}
+
+.. versionadded:: 0.4
+
+Aggregation
+===========
+MongoDB provides some aggregation methods out of the box, but there are not as
+many as you typically get with an RDBMS. MongoEngine provides a wrapper around
+the built-in methods and provides some of its own, which are implemented as
+Javascript code that is executed on the database server.
+
+Counting results
+----------------
+Just as with limiting and skipping results, there is a method on
+:class:`~mongoengine.queryset.QuerySet` objects --
+:meth:`~mongoengine.queryset.QuerySet.count`, but there is also a more Pythonic
+way of achieving this::
+
+    num_users = len(User.objects)
+
+Further aggregation
+-------------------
+You may sum over the values of a specific field on documents using
+:meth:`~mongoengine.queryset.QuerySet.sum`::
+
+    yearly_expense = Employee.objects.sum('salary')
+
+.. note::
+
+   If the field isn't present on a document, that document will be ignored from
+   the sum.
+
+To get the average (mean) of a field on a collection of documents, use
+:meth:`~mongoengine.queryset.QuerySet.average`::
+
+    mean_age = User.objects.average('age')
+
+As MongoDB provides native lists, MongoEngine provides a helper method to get a
+dictionary of the frequencies of items in lists across an entire collection --
+:meth:`~mongoengine.queryset.QuerySet.item_frequencies`. An example of its use
+would be generating "tag-clouds"::
+
+    class Article(Document):
+        tag = ListField(StringField())
+
+    # After adding some tagged articles...
+    tag_freqs = Article.objects.item_frequencies('tag', normalize=True)
+
+    from operator import itemgetter
+    top_tags = sorted(tag_freqs.items(), key=itemgetter(1), reverse=True)[:10]
+
+Retrieving a subset of fields
+=============================
+Sometimes a subset of fields on a :class:`~mongoengine.Document` is required,
+and for efficiency only these should be retrieved from the database. This issue
+is especially important for MongoDB, as fields may often be extremely large
+(e.g. a :class:`~mongoengine.ListField` of
+:class:`~mongoengine.EmbeddedDocument`\ s, which represent the comments on a
+blog post. To select only a subset of fields, use
+:meth:`~mongoengine.queryset.QuerySet.only`, specifying the fields you want to
+retrieve as its arguments. Note that if fields that are not downloaded are
+accessed, their default value (or :attr:`None` if no default value is provided)
+will be given::
+
+    >>> class Film(Document):
+    ...     title = StringField()
+    ...     year = IntField()
+    ...     rating = IntField(default=3)
+    ...
+    >>> Film(title='The Shawshank Redemption', year=1994, rating=5).save()
+    >>> f = Film.objects.only('title').first()
+    >>> f.title
+    'The Shawshank Redemption'
+    >>> f.year   # None
+    >>> f.rating # default value
+    3
+
+.. note::
+
+    The :meth:`~mongoengine.queryset.QuerySet.exclude` is the opposite of
+    :meth:`~mongoengine.queryset.QuerySet.only` if you want to exclude a field.
+
+If you later need the missing fields, just call
+:meth:`~mongoengine.Document.reload` on your document.
+
+Advanced queries
+================
+Sometimes calling a :class:`~mongoengine.queryset.QuerySet` object with keyword
+arguments can't fully express the query you want to use -- for example if you
+need to combine a number of constraints using *and* and *or*. This is made
+possible in MongoEngine through the :class:`~mongoengine.queryset.Q` class.
+A :class:`~mongoengine.queryset.Q` object represents part of a query, and
+can be initialised using the same keyword-argument syntax you use to query
+documents. To build a complex query, you may combine
+:class:`~mongoengine.queryset.Q` objects using the ``&`` (and) and ``|`` (or)
+operators. To use a :class:`~mongoengine.queryset.Q` object, pass it in as the
+first positional argument to :attr:`Document.objects` when you filter it by
+calling it with keyword arguments::
+
+    # Get published posts
+    Post.objects(Q(published=True) | Q(publish_date__lte=datetime.now()))
+
+    # Get top posts
+    Post.objects((Q(featured=True) & Q(hits__gte=1000)) | Q(hits__gte=5000))
+
+.. _guide-atomic-updates:
+
+Atomic updates
+==============
+Documents may be updated atomically by using the
+:meth:`~mongoengine.queryset.QuerySet.update_one` and
+:meth:`~mongoengine.queryset.QuerySet.update` methods on a
+:meth:`~mongoengine.queryset.QuerySet`. There are several different "modifiers"
+that you may use with these methods:
+
+* ``set`` -- set a particular value
+* ``unset`` -- delete a particular value (since MongoDB v1.3+)
+* ``inc`` -- increment a value by a given amount
+* ``dec`` -- decrement a value by a given amount
+* ``pop`` -- remove the last item from a list
+* ``push`` -- append a value to a list
+* ``push_all`` -- append several values to a list
+* ``pop`` -- remove the first or last element of a list
+* ``pull`` -- remove a value from a list
+* ``pull_all`` -- remove several values from a list
+* ``add_to_set`` -- add value to a list only if its not in the list already
+
+The syntax for atomic updates is similar to the querying syntax, but the
+modifier comes before the field, not after it::
+
+    >>> post = BlogPost(title='Test', page_views=0, tags=['database'])
+    >>> post.save()
+    >>> BlogPost.objects(id=post.id).update_one(inc__page_views=1)
+    >>> post.reload()  # the document has been changed, so we need to reload it
+    >>> post.page_views
+    1
+    >>> BlogPost.objects(id=post.id).update_one(set__title='Example Post')
+    >>> post.reload()
+    >>> post.title
+    'Example Post'
+    >>> BlogPost.objects(id=post.id).update_one(push__tags='nosql')
+    >>> post.reload()
+    >>> post.tags
+    ['database', 'nosql']
+
+.. note ::
+
+    In version 0.5 the :meth:`~mongoengine.Document.save` runs atomic updates
+    on changed documents by tracking changes to that document.
+
+The positional operator allows you to update list items without knowing the
+index position, therefore making the update a single atomic operation.  As we
+cannot use the `$` syntax in keyword arguments it has been mapped to `S`::
+
+    >>> post = BlogPost(title='Test', page_views=0, tags=['database', 'mongo'])
+    >>> post.save()
+    >>> BlogPost.objects(id=post.id, tags='mongo').update(set__tags__S='mongodb')
+    >>> post.reload()
+    >>> post.tags
+    ['database', 'mongodb']
+
+.. note ::
+    Currently only top level lists are handled, future versions of mongodb /
+    pymongo plan to support nested positional operators.  See `The $ positional
+    operator <http://www.mongodb.org/display/DOCS/Updating#Updating-The%24positionaloperator>`_.
+
+Server-side javascript execution
+================================
+Javascript functions may be written and sent to the server for execution. The
+result of this is the return value of the Javascript function. This
+functionality is accessed through the
+:meth:`~mongoengine.queryset.QuerySet.exec_js` method on
+:meth:`~mongoengine.queryset.QuerySet` objects. Pass in a string containing a
+Javascript function as the first argument.
+
+The remaining positional arguments are names of fields that will be passed into
+you Javascript function as its arguments. This allows functions to be written
+that may be executed on any field in a collection (e.g. the
+:meth:`~mongoengine.queryset.QuerySet.sum` method, which accepts the name of
+the field to sum over as its argument). Note that field names passed in in this
+manner are automatically translated to the names used on the database (set
+using the :attr:`name` keyword argument to a field constructor).
+
+Keyword arguments to :meth:`~mongoengine.queryset.QuerySet.exec_js` are
+combined into an object called :attr:`options`, which is available in the
+Javascript function. This may be used for defining specific parameters for your
+function.
+
+Some variables are made available in the scope of the Javascript function:
+
+* ``collection`` -- the name of the collection that corresponds to the
+  :class:`~mongoengine.Document` class that is being used; this should be
+  used to get the :class:`Collection` object from :attr:`db` in Javascript
+  code
+* ``query`` -- the query that has been generated by the
+  :class:`~mongoengine.queryset.QuerySet` object; this may be passed into
+  the :meth:`find` method on a :class:`Collection` object in the Javascript
+  function
+* ``options`` -- an object containing the keyword arguments passed into
+  :meth:`~mongoengine.queryset.QuerySet.exec_js`
+
+The following example demonstrates the intended usage of
+:meth:`~mongoengine.queryset.QuerySet.exec_js` by defining a function that sums
+over a field on a document (this functionality is already available throught
+:meth:`~mongoengine.queryset.QuerySet.sum` but is shown here for sake of
+example)::
+
+    def sum_field(document, field_name, include_negatives=True):
+        code = """
+        function(sumField) {
+            var total = 0.0;
+            db[collection].find(query).forEach(function(doc) {
+                var val = doc[sumField];
+                if (val >= 0.0 || options.includeNegatives) {
+                    total += val;
+                }
+            });
+            return total;
+        }
+        """
+        options = {'includeNegatives': include_negatives}
+        return document.objects.exec_js(code, field_name, **options)
+
+As fields in MongoEngine may use different names in the database (set using the
+:attr:`db_field` keyword argument to a :class:`Field` constructor), a mechanism
+exists for replacing MongoEngine field names with the database field names in
+Javascript code. When accessing a field on a collection object, use
+square-bracket notation, and prefix the MongoEngine field name with a tilde.
+The field name that follows the tilde will be translated to the name used in
+the database. Note that when referring to fields on embedded documents,
+the name of the :class:`~mongoengine.EmbeddedDocumentField`, followed by a dot,
+should be used before the name of the field on the embedded document. The
+following example shows how the substitutions are made::
+
+    class Comment(EmbeddedDocument):
+        content = StringField(db_field='body')
+
+    class BlogPost(Document):
+        title = StringField(db_field='doctitle')
+        comments = ListField(EmbeddedDocumentField(Comment), name='cs')
+
+    # Returns a list of dictionaries. Each dictionary contains a value named
+    # "document", which corresponds to the "title" field on a BlogPost, and
+    # "comment", which corresponds to an individual comment. The substitutions
+    # made are shown in the comments.
+    BlogPost.objects.exec_js("""
+    function() {
+        var comments = [];
+        db[collection].find(query).forEach(function(doc) {
+            // doc[~comments] -> doc["cs"]
+            var docComments = doc[~comments];
+
+            for (var i = 0; i < docComments.length; i++) {
+                // doc[~comments][i] -> doc["cs"][i]
+                var comment = doc[~comments][i];
+
+                comments.push({
+                    // doc[~title] -> doc["doctitle"]
+                    'document': doc[~title],
+
+                    // comment[~comments.content] -> comment["body"]
+                    'comment': comment[~comments.content]
+                });
+            }
+        });
+        return comments;
+    }
+    """)

docs/guide/signals.rst

@@ -0,0 +1,49 @@
+.. _signals:
+
+Signals
+=======
+
+.. versionadded:: 0.5
+
+Signal support is provided by the excellent `blinker`_ library and
+will gracefully fall back if it is not available.
+
+
+The following document signals exist in MongoEngine and are pretty self explaintary:
+
+  * `mongoengine.signals.pre_init`
+  * `mongoengine.signals.post_init`
+  * `mongoengine.signals.pre_save`
+  * `mongoengine.signals.post_save`
+  * `mongoengine.signals.pre_delete`
+  * `mongoengine.signals.post_delete`
+
+Example usage::
+
+    from mongoengine import *
+    from mongoengine import signals
+
+    class Author(Document):
+        name = StringField()
+
+        def __unicode__(self):
+            return self.name
+
+        @classmethod
+        def pre_save(cls, sender, document, **kwargs):
+            logging.debug("Pre Save: %s" % document.name)
+
+        @classmethod
+        def post_save(cls, sender, document, **kwargs):
+            logging.debug("Post Save: %s" % document.name)
+            if 'created' in kwargs:
+                if kwargs['created']:
+                    logging.debug("Created")
+                else:
+                    logging.debug("Updated")
+
+        signals.pre_save.connect(Author.pre_save, sender=Author)
+        signals.post_save.connect(Author.post_save, sender=Author)
+
+
+.. _blinker: http://pypi.python.org/pypi/blinker

docs/index.rst

@@ -1,27 +1,63 @@
+==============================
 MongoEngine User Documentation
-=======================================
+==============================
 
-MongoEngine is an Object-Document Mapper, written in Python for working with 
+**MongoEngine** is an Object-Document Mapper, written in Python for working with
 MongoDB. To install it, simply run
 
 .. code-block:: console
 
-    # easy_install mongoengine
+    # pip install -U mongoengine
 
-The source is available on `GitHub <http://github.com/hmarr/mongoengine>`_.
+:doc:`tutorial`
+  Start here for a quick overview.
+
+:doc:`guide/index`
+  The Full guide to MongoEngine
+
+:doc:`apireference`
+  The complete API documentation.
+
+:doc:`django`
+  Using MongoEngine and Django
+
+Community
+---------
+
+To get help with using MongoEngine, use the `MongoEngine Users mailing list
+<http://groups.google.com/group/mongoengine-users>`_ or come chat on the
+`#mongoengine IRC channel <irc://irc.freenode.net/mongoengine>`_.
+
+Contributing
+------------
+
+The source is available on `GitHub <http://github.com/hmarr/mongoengine>`_ and
+contributions are always encouraged. Contributions can be as simple as
+minor tweaks to this documentation. To contribute, fork the project on
+`GitHub <http://github.com/hmarr/mongoengine>`_ and send a
+pull request.
+
+Also, you can join the developers' `mailing list
+<http://groups.google.com/group/mongoengine-dev>`_.
+
+Changes
+-------
+See the :doc:`changelog` for a full list of changes to MongoEngine.
 
 .. toctree::
-   :maxdepth: 2
+   :hidden:
 
    tutorial
-   userguide
+   guide/index
    apireference
    django
    changelog
+   upgrade
 
 Indices and tables
-==================
+------------------
 
 * :ref:`genindex`
+* :ref:`modindex`
 * :ref:`search`
 

docs/tutorial.rst

@@ -22,7 +22,7 @@ function. The only argument we need to provide is the name of the MongoDB
 database to use::
 
     from mongoengine import *
-    
+
     connect('tumblelog')
 
 For more information about connecting to MongoDB see :ref:`guide-connecting`.
@@ -112,7 +112,7 @@ link table, we can just store a list of tags in each post. So, for both
 efficiency and simplicity's sake, we'll store the tags as strings directly
 within the post, rather than storing references to tags in a separate
 collection. Especially as tags are generally very short (often even shorter
-than a document's id), this denormalisation won't impact very strongly on the 
+than a document's id), this denormalisation won't impact very strongly on the
 size of our database. So let's take a look that the code our modified
 :class:`Post` class::
 
@@ -152,6 +152,21 @@ We can then store a list of comment documents in our post document::
         tags = ListField(StringField(max_length=30))
         comments = ListField(EmbeddedDocumentField(Comment))
 
+Handling deletions of references
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The :class:`~mongoengine.ReferenceField` object takes a keyword
+`reverse_delete_rule` for handling deletion rules if the reference is deleted.
+To delete all the posts if a user is deleted set the rule::
+
+    class Post(Document):
+        title = StringField(max_length=120, required=True)
+        author = ReferenceField(User, reverse_delete_rule=CASCADE)
+        tags = ListField(StringField(max_length=30))
+        comments = ListField(EmbeddedDocumentField(Comment))
+
+See :class:`~mongoengine.ReferenceField` for more information.
+
 Adding data to our Tumblelog
 ============================
 Now that we've defined how our documents will be structured, let's start adding
@@ -250,5 +265,5 @@ the first matched by the query you provide. Aggregation functions may also be
 used on :class:`~mongoengine.queryset.QuerySet` objects::
 
     num_posts = Post.objects(tags='mongodb').count()
-    print 'Found % posts with tag "mongodb"' % num_posts
-    
+    print 'Found %d posts with tag "mongodb"' % num_posts
+

docs/upgrade.rst

@@ -0,0 +1,97 @@
+=========
+Upgrading
+=========
+
+0.4 to 0.5
+===========
+
+There have been the following backwards incompatibilities from 0.4 to 0.5.  The
+main areas of changed are: choices in fields, map_reduce and collection names.
+
+Choice options:
+--------------
+
+Are now expected to be an iterable of tuples, with  the first element in each
+tuple being the actual value to be stored. The second element is the
+human-readable name for the option.
+
+
+PyMongo / MongoDB
+-----------------
+
+map reduce now requires pymongo 1.11+- The pymongo merge_output and reduce_output
+parameters, have been depreciated.
+
+More methods now use map_reduce as db.eval is not supported for sharding as such
+the following have been changed:
+
+    * :meth:`~mongoengine.queryset.QuerySet.sum`
+    * :meth:`~mongoengine.queryset.QuerySet.average`
+    * :meth:`~mongoengine.queryset.QuerySet.item_frequencies`
+
+
+Default collection naming
+-------------------------
+
+Previously it was just lowercase, its now much more pythonic and readable as its
+lowercase and underscores, previously ::
+
+    class MyAceDocument(Document):
+        pass
+
+    MyAceDocument._meta['collection'] == myacedocument
+
+In 0.5 this will change to ::
+
+    class MyAceDocument(Document):
+        pass
+
+    MyAceDocument._get_collection_name() == my_ace_document
+
+To upgrade use a Mixin class to set meta like so ::
+
+    class BaseMixin(object):
+        meta = {
+            'collection': lambda c: c.__name__.lower()
+        }
+
+    class MyAceDocument(Document, BaseMixin):
+        pass
+
+    MyAceDocument._get_collection_name() == myacedocument
+
+Alternatively, you can rename your collections eg ::
+
+    from mongoengine.connection import _get_db
+    from mongoengine.base import _document_registry
+
+    def rename_collections():
+        db = _get_db()
+
+        failure = False
+
+        collection_names = [d._get_collection_name() for d in _document_registry.values()]
+
+        for new_style_name in collection_names:
+            if not new_style_name:  # embedded documents don't have collections
+                continue
+            old_style_name = new_style_name.replace('_', '')
+
+            if old_style_name == new_style_name:
+                continue  # Nothing to do
+
+            existing = db.collection_names()
+            if old_style_name in existing:
+                if new_style_name in existing:
+                    failure = True
+                    print "FAILED to rename: %s to %s (already exists)" % (
+                        old_style_name, new_style_name)
+                else:
+                    db[old_style_name].rename(new_style_name)
+                    print "Renamed:  %s to %s" % (old_style_name, new_style_name)
+
+        if failure:
+            print "Upgrading  collection names failed"
+        else:
+            print "Upgraded collection names"
+

docs/userguide.rst

@@ -1,534 +0,0 @@
-==========
-User Guide
-==========
-
-Installing
-==========
-MongoEngine is available on PyPI, so to use it you can use 
-:program:`easy_install`
-    
-.. code-block:: console
-
-    # easy_install mongoengine
-
-Alternatively, if you don't have setuptools installed, `download it from PyPi 
-<http://pypi.python.org/pypi/mongoengine/>`_ and run
-
-.. code-block:: console
-
-    # python setup.py install
-
-.. _guide-connecting:
-
-Connecting to MongoDB
-=====================
-To connect to a running instance of :program:`mongod`, use the
-:func:`~mongoengine.connect` function. The first argument is the name of the
-database to connect to. If the database does not exist, it will be created. If
-the database requires authentication, :attr:`username` and :attr:`password`
-arguments may be provided::
-
-    from mongoengine import connect
-    connect('project1', username='webapp', password='pwd123')
-
-By default, MongoEngine assumes that the :program:`mongod` instance is running
-on **localhost** on port **27017**. If MongoDB is running elsewhere, you may
-provide :attr:`host` and :attr:`port` arguments to
-:func:`~mongoengine.connect`::
-
-    connect('project1', host='192.168.1.35', port=12345)
-
-Defining documents
-==================
-In MongoDB, a **document** is roughly equivalent to a **row** in an RDBMS. When
-working with relational databases, rows are stored in **tables**, which have a
-strict **schema** that the rows follow. MongoDB stores documents in
-**collections** rather than tables - the principle difference is that no schema 
-is enforced at a database level. 
-
-Defining a document's schema
-----------------------------
-MongoEngine allows you to define schemata for documents as this helps to reduce
-coding errors, and allows for utility methods to be defined on fields which may
-be present. 
-
-To define a schema for a document, create a class that inherits from
-:class:`~mongoengine.Document`. Fields are specified by adding **field
-objects** as class attributes to the document class::
-
-    from mongoengine import *
-    import datetime
-    
-    class Page(Document):
-        title = StringField(max_length=200, required=True)
-        date_modified = DateTimeField(default=datetime.now)
-
-Fields
-------
-By default, fields are not required. To make a field mandatory, set the
-:attr:`required` keyword argument of a field to ``True``. Fields also may have
-validation constraints available (such as :attr:`max_length` in the example
-above). Fields may also take default values, which will be used if a value is
-not provided. Default values may optionally be a callable, which will be called
-to retrieve the value (such as in the above example). The field types available 
-are as follows:
-
-* :class:`~mongoengine.StringField`
-* :class:`~mongoengine.IntField`
-* :class:`~mongoengine.FloatField`
-* :class:`~mongoengine.DateTimeField`
-* :class:`~mongoengine.ListField`
-* :class:`~mongoengine.ObjectIdField`
-* :class:`~mongoengine.EmbeddedDocumentField`
-* :class:`~mongoengine.ReferenceField`
-
-List fields
-^^^^^^^^^^^
-MongoDB allows the storage of lists of items. To add a list of items to a
-:class:`~mongoengine.Document`, use the :class:`~mongoengine.ListField` field
-type. :class:`~mongoengine.ListField` takes another field object as its first
-argument, which specifies which type elements may be stored within the list::
-
-    class Page(Document):
-        tags = ListField(StringField(max_length=50))
-
-Embedded documents
-^^^^^^^^^^^^^^^^^^
-MongoDB has the ability to embed documents within other documents. Schemata may
-be defined for these embedded documents, just as they may be for regular
-documents. To create an embedded document, just define a document as usual, but
-inherit from :class:`~mongoengine.EmbeddedDocument` rather than 
-:class:`~mongoengine.Document`::
-
-    class Comment(EmbeddedDocument):
-        content = StringField()
-
-To embed the document within another document, use the
-:class:`~mongoengine.EmbeddedDocumentField` field type, providing the embedded
-document class as the first argument::
-
-    class Page(Document):
-        comments = ListField(EmbeddedDocumentField(Comment))
-
-    comment1 = Comment('Good work!')
-    comment2 = Comment('Nice article!')
-    page = Page(comments=[comment1, comment2])
-
-Reference fields
-^^^^^^^^^^^^^^^^
-References may be stored to other documents in the database using the
-:class:`~mongoengine.ReferenceField`. Pass in another document class as the
-first argument to the constructor, then simply assign document objects to the
-field::
-    
-    class User(Document):
-        name = StringField()
-
-    class Page(Document):
-        content = StringField()
-        author = ReferenceField(User)
-
-    john = User(name="John Smith")
-    john.save()
-
-    post = Page(content="Test Page")
-    post.author = john
-    post.save()
-
-The :class:`User` object is automatically turned into a reference behind the
-scenes, and dereferenced when the :class:`Page` object is retrieved.
-
-Uniqueness constraints
-^^^^^^^^^^^^^^^^^^^^^^
-MongoEngine allows you to specify that a field should be unique across a
-collection by providing ``unique=True`` to a :class:`~mongoengine.Field`\ 's
-constructor. If you try to save a document that has the same value for a unique
-field as a document that is already in the database, a 
-:class:`~mongoengine.OperationError` will be raised. You may also specify
-multi-field uniqueness constraints by using :attr:`unique_with`, which may be
-either a single field name, or a list or tuple of field names::
-
-    class User(Document):
-        username = StringField(unique=True)
-        first_name = StringField()
-        last_name = StringField(unique_with='last_name')
-
-Document collections
---------------------
-Document classes that inherit **directly** from :class:`~mongoengine.Document`
-will have their own **collection** in the database. The name of the collection
-is by default the name of the class, coverted to lowercase (so in the example
-above, the collection would be called `page`). If you need to change the name
-of the collection (e.g. to use MongoEngine with an existing database), then
-create a class dictionary attribute called :attr:`meta` on your document, and
-set :attr:`collection` to the name of the collection that you want your
-document class to use::
-
-    class Page(Document):
-        title = StringField(max_length=200, required=True)
-        meta = {'collection': 'cmsPage'}
-
-Capped collections
-^^^^^^^^^^^^^^^^^^
-A :class:`~mongoengine.Document` may use a **Capped Collection** by specifying
-:attr:`max_documents` and :attr:`max_size` in the :attr:`meta` dictionary.
-:attr:`max_documents` is the maximum number of documents that is allowed to be
-stored in the collection, and :attr:`max_size` is the maximum size of the
-collection in bytes. If :attr:`max_size` is not specified and
-:attr:`max_documents` is, :attr:`max_size` defaults to 10000000 bytes (10MB).
-The following example shows a :class:`Log` document that will be limited to 
-1000 entries and 2MB of disk space::
-
-    class Log(Document):
-        ip_address = StringField()
-        meta = {'max_documents': 1000, 'max_size': 2000000}
-
-Indexes
--------
-You can specify indexes on collections to make querying faster. This is done
-by creating a list of index specifications called :attr:`indexes` in the
-:attr:`~mongoengine.Document.meta` dictionary, where an index specification may
-either be a single field name, or a tuple containing multiple field names. A
-direction may be specified on fields by prefixing the field name with a **+**
-or a **-** sign. Note that direction only matters on multi-field indexes. ::
-
-    class Page(Document):
-        title = StringField()
-        rating = StringField()
-        meta = {
-            'indexes': ['title', ('title', '-rating')]
-        }
-        
-Ordering
---------
-A default ordering can be specified for your
-:class:`~mongoengine.queryset.QuerySet` using the :attr:`ordering` attribute of
-:attr:`~mongoengine.Document.meta`.  Ordering will be applied when the
-:class:`~mongoengine.queryset.QuerySet` is created, and can be overridden by
-subsequent calls to :meth:`~mongoengine.queryset.QuerySet.order_by`. ::
-
-    from datetime import datetime
-
-    class BlogPost(Document):
-        title = StringField()
-        published_date = DateTimeField()
-
-        meta = {
-            'ordering': ['-published_date']
-        }
-
-    blog_post_1 = BlogPost(title="Blog Post #1")
-    blog_post_1.published_date = datetime(2010, 1, 5, 0, 0 ,0))
-
-    blog_post_2 = BlogPost(title="Blog Post #2") 
-    blog_post_2.published_date = datetime(2010, 1, 6, 0, 0 ,0))
-
-    blog_post_3 = BlogPost(title="Blog Post #3")
-    blog_post_3.published_date = datetime(2010, 1, 7, 0, 0 ,0))
-
-    blog_post_1.save()
-    blog_post_2.save()
-    blog_post_3.save()
-
-    # get the "first" BlogPost using default ordering
-    # from BlogPost.meta.ordering
-    latest_post = BlogPost.objects.first() 
-    self.assertEqual(latest_post.title, "Blog Post #3")
-
-    # override default ordering, order BlogPosts by "published_date"
-    first_post = BlogPost.objects.order_by("+published_date").first()
-    self.assertEqual(first_post.title, "Blog Post #1")
-
-Document inheritance
---------------------
-To create a specialised type of a :class:`~mongoengine.Document` you have
-defined, you may subclass it and add any extra fields or methods you may need.
-As this is new class is not a direct subclass of
-:class:`~mongoengine.Document`, it will not be stored in its own collection; it
-will use the same collection as its superclass uses. This allows for more
-convenient and efficient retrieval of related documents::
-
-    # Stored in a collection named 'page'
-    class Page(Document):
-        title = StringField(max_length=200, required=True)
-
-    # Also stored in the collection named 'page'
-    class DatedPage(Page):
-        date = DateTimeField()
-
-Working with existing data
-^^^^^^^^^^^^^^^^^^^^^^^^^^
-To enable correct retrieval of documents involved in this kind of heirarchy,
-two extra attributes are stored on each document in the database: :attr:`_cls`
-and :attr:`_types`. These are hidden from the user through the MongoEngine
-interface, but may not be present if you are trying to use MongoEngine with 
-an existing database. For this reason, you may disable this inheritance
-mechansim, removing the dependency of :attr:`_cls` and :attr:`_types`, enabling
-you to work with existing databases. To disable inheritance on a document
-class, set :attr:`allow_inheritance` to ``False`` in the :attr:`meta`
-dictionary::
-
-    # Will work with data in an existing collection named 'cmsPage'
-    class Page(Document):
-        title = StringField(max_length=200, required=True)
-        meta = {
-            'collection': 'cmsPage',
-            'allow_inheritance': False,
-        }
-
-Documents instances
-===================
-To create a new document object, create an instance of the relevant document
-class, providing values for its fields as its constructor keyword arguments.
-You may provide values for any of the fields on the document::
-    
-    >>> page = Page(title="Test Page")
-    >>> page.title
-    'Test Page'
-
-You may also assign values to the document's fields using standard object 
-attribute syntax::
-
-    >>> page.title = "Example Page"
-    >>> page.title
-    'Example Page'
-
-Saving and deleting documents
------------------------------
-To save the document to the database, call the
-:meth:`~mongoengine.Document.save` method. If the document does not exist in
-the database, it will be created. If it does already exist, it will be
-updated.
-
-To delete a document, call the :meth:`~mongoengine.Document.delete` method.
-Note that this will only work if the document exists in the database and has a
-valide :attr:`id`.
-
-Document IDs
-------------
-Each document in the database has a unique id. This may be accessed through the
-:attr:`id` attribute on :class:`~mongoengine.Document` objects. Usually, the id
-will be generated automatically by the database server when the object is save,
-meaning that you may only access the :attr:`id` field once a document has been
-saved::
-
-    >>> page = Page(title="Test Page")
-    >>> page.id
-    >>> page.save()
-    >>> page.id
-    ObjectId('123456789abcdef000000000')
-
-Alternatively, you may define one of your own fields to be the document's
-"primary key" by providing ``primary_key=True`` as a keyword argument to a
-field's constructor. Under the hood, MongoEngine will use this field as the
-:attr:`id`; in fact :attr:`id` is actually aliased to your primary key field so
-you may still use :attr:`id` to access the primary key if you want::
-
-    >>> class User(Document):
-    ...     email = StringField(primary_key=True)
-    ...     name = StringField()
-    ...
-    >>> bob = User(email='bob@example.com', name='Bob')
-    >>> bob.save()
-    >>> bob.id == bob.email == 'bob@example.com'
-    True
-
-.. note::
-   If you define your own primary key field, the field implicitly becomes
-   required, so a :class:`ValidationError` will be thrown if you don't provide
-   it.
-
-Querying the database
-=====================
-:class:`~mongoengine.Document` classes have an :attr:`objects` attribute, which
-is used for accessing the objects in the database associated with the class.
-The :attr:`objects` attribute is actually a
-:class:`~mongoengine.queryset.QuerySetManager`, which creates and returns a new
-a new :class:`~mongoengine.queryset.QuerySet` object on access. The
-:class:`~mongoengine.queryset.QuerySet` object may may be iterated over to
-fetch documents from the database::
-
-    # Prints out the names of all the users in the database
-    for user in User.objects:
-        print user.name
-
-Filtering queries
------------------
-The query may be filtered by calling the
-:class:`~mongoengine.queryset.QuerySet` object with field lookup keyword 
-arguments. The keys in the keyword arguments correspond to fields on the
-:class:`~mongoengine.Document` you are querying::
-
-    # This will return a QuerySet that will only iterate over users whose
-    # 'country' field is set to 'uk'
-    uk_users = User.objects(country='uk')
-
-Fields on embedded documents may also be referred to using field lookup syntax
-by using a double-underscore in place of the dot in object attribute access
-syntax::
-    
-    # This will return a QuerySet that will only iterate over pages that have
-    # been written by a user whose 'country' field is set to 'uk'
-    uk_pages = Page.objects(author__country='uk')
-
-Querying lists
-^^^^^^^^^^^^^^
-On most fields, this syntax will look up documents where the field specified
-matches the given value exactly, but when the field refers to a
-:class:`~mongoengine.ListField`, a single item may be provided, in which case
-lists that contain that item will be matched::
-
-    class Page(Document):
-        tags = ListField(StringField())
-
-    # This will match all pages that have the word 'coding' as an item in the
-    # 'tags' list
-    Page.objects(tags='coding')
-
-Query operators
----------------
-Operators other than equality may also be used in queries; just attach the
-operator name to a key with a double-underscore::
-    
-    # Only find users whose age is 18 or less
-    young_users = Users.objects(age__lte=18)
-
-Available operators are as follows:
-
-* ``neq`` -- not equal to
-* ``lt`` -- less than
-* ``lte`` -- less than or equal to
-* ``gt`` -- greater than
-* ``gte`` -- greater than or equal to
-* ``in`` -- value is in list (a list of values should be provided)
-* ``nin`` -- value is not in list (a list of values should be provided)
-* ``mod`` -- ``value % x == y``, where ``x`` and ``y`` are two provided values
-* ``all`` -- every item in array is in list of values provided
-* ``size`` -- the size of the array is 
-* ``exists`` -- value for field exists
-
-Limiting and skipping results
------------------------------
-Just as with traditional ORMs, you may limit the number of results returned, or
-skip a number or results in you query.
-:meth:`~mongoengine.queryset.QuerySet.limit` and
-:meth:`~mongoengine.queryset.QuerySet.skip` and methods are available on
-:class:`~mongoengine.queryset.QuerySet` objects, but the prefered syntax for
-achieving this is using array-slicing syntax::
-
-    # Only the first 5 people
-    users = User.objects[:5]
-
-    # All except for the first 5 people
-    users = User.objects[5:]
-
-    # 5 users, starting from the 10th user found
-    users = User.objects[10:15]
-
-Aggregation
------------
-MongoDB provides some aggregation methods out of the box, but there are not as
-many as you typically get with an RDBMS. MongoEngine provides a wrapper around
-the built-in methods and provides some of its own, which are implemented as
-Javascript code that is executed on the database server.
-
-Counting results
-^^^^^^^^^^^^^^^^
-Just as with limiting and skipping results, there is a method on
-:class:`~mongoengine.queryset.QuerySet` objects -- 
-:meth:`~mongoengine.queryset.QuerySet.count`, but there is also a more Pythonic
-way of achieving this::
-
-    num_users = len(User.objects)
-
-Further aggregation
-^^^^^^^^^^^^^^^^^^^
-You may sum over the values of a specific field on documents using
-:meth:`~mongoengine.queryset.QuerySet.sum`::
-
-    yearly_expense = Employee.objects.sum('salary')
-
-.. note::
-   If the field isn't present on a document, that document will be ignored from
-   the sum.
-
-To get the average (mean) of a field on a collection of documents, use
-:meth:`~mongoengine.queryset.QuerySet.average`::
-
-    mean_age = User.objects.average('age')
-
-As MongoDB provides native lists, MongoEngine provides a helper method to get a
-dictionary of the frequencies of items in lists across an entire collection --
-:meth:`~mongoengine.queryset.QuerySet.item_frequencies`. An example of its use
-would be generating "tag-clouds"::
-
-    class Article(Document):
-        tag = ListField(StringField())
-
-    # After adding some tagged articles...
-    tag_freqs = Article.objects.item_frequencies('tag', normalize=True)
-
-    from operator import itemgetter
-    top_tags = sorted(tag_freqs.items(), key=itemgetter(1), reverse=True)[:10]
-
-Advanced queries
-----------------
-Sometimes calling a :class:`~mongoengine.queryset.QuerySet` object with keyword
-arguments can't fully express the query you want to use -- for example if you
-need to combine a number of constraints using *and* and *or*. This is made 
-possible in MongoEngine through the :class:`~mongoengine.queryset.Q` class.
-A :class:`~mongoengine.queryset.Q` object represents part of a query, and
-can be initialised using the same keyword-argument syntax you use to query
-documents. To build a complex query, you may combine 
-:class:`~mongoengine.queryset.Q` objects using the ``&`` (and) and ``|`` (or)
-operators. To use :class:`~mongoengine.queryset.Q` objects, pass them in
-as positional arguments to :attr:`Document.objects` when you filter it by
-calling it with keyword arguments::
-
-    # Get published posts
-    Post.objects(Q(published=True) | Q(publish_date__lte=datetime.now()))
-
-    # Get top posts
-    Post.objects((Q(featured=True) & Q(hits__gte=1000)) | Q(hits__gte=5000))
-
-.. warning::
-   Only use these advanced queries if absolutely necessary as they will execute
-   significantly slower than regular queries. This is because they are not
-   natively supported by MongoDB -- they are compiled to Javascript and sent
-   to the server for execution.
-
-Atomic updates
---------------
-Documents may be updated atomically by using the
-:meth:`~mongoengine.queryset.QuerySet.update_one` and
-:meth:`~mongoengine.queryset.QuerySet.update` methods on a 
-:meth:`~mongoengine.queryset.QuerySet`. There are several different "modifiers"
-that you may use with these methods:
-
-* ``set`` -- set a particular value
-* ``unset`` -- delete a particular value (since MongoDB v1.3+)
-* ``inc`` -- increment a value by a given amount
-* ``dec`` -- decrement a value by a given amount
-* ``push`` -- append a value to a list
-* ``push_all`` -- append several values to a list
-* ``pull`` -- remove a value from a list
-* ``pull_all`` -- remove several values from a list
-
-The syntax for atomic updates is similar to the querying syntax, but the 
-modifier comes before the field, not after it::
-    
-    >>> post = BlogPost(title='Test', page_views=0, tags=['database'])
-    >>> post.save()
-    >>> BlogPost.objects(id=post.id).update_one(inc__page_views=1)
-    >>> post.reload()  # the document has been changed, so we need to reload it
-    >>> post.page_views
-    1
-    >>> BlogPost.objects(id=post.id).update_one(set__title='Example Post')
-    >>> post.reload()
-    >>> post.title
-    'Example Post'
-    >>> BlogPost.objects(id=post.id).update_one(push__tags='nosql')
-    >>> post.reload()
-    >>> post.tags
-    ['database', 'nosql']
-

mongoengine/__init__.py

@@ -6,13 +6,16 @@ import connection
 from connection import *
 import queryset
 from queryset import *
+import signals
+from signals import *
 
 __all__ = (document.__all__ + fields.__all__ + connection.__all__ +
-           queryset.__all__)
+           queryset.__all__ + signals.__all__)
 
 __author__ = 'Harry Marr'
 
-VERSION = (0, 2, 1)
+VERSION = (0, 5, 1)
+
 
 def get_version():
     version = '%s.%s' % (VERSION[0], VERSION[1])
@@ -21,4 +24,3 @@ def get_version():
     return version
 
 __version__ = get_version()
-

mongoengine/connection.py

@@ -1,62 +1,82 @@
 from pymongo import Connection
-
+import multiprocessing
+import threading
 
 __all__ = ['ConnectionError', 'connect']
 
 
-_connection_settings = {
+_connection_defaults = {
     'host': 'localhost',
     'port': 27017,
-    'pool_size': 1,
 }
-_connection = None
+_connection = {}
+_connection_settings = _connection_defaults.copy()
 
 _db_name = None
 _db_username = None
 _db_password = None
-_db = None
+_db = {}
 
 
 class ConnectionError(Exception):
     pass
 
 
-def _get_connection():
+def _get_connection(reconnect=False):
+    """Handles the connection to the database
+    """
     global _connection
+    identity = get_identity()
     # Connect to the database if not already connected
-    if _connection is None:
+    if _connection.get(identity) is None or reconnect:
         try:
-            _connection = Connection(**_connection_settings)
-        except:
-            raise ConnectionError('Cannot connect to the database')
-    return _connection
+            _connection[identity] = Connection(**_connection_settings)
+        except Exception, e:
+            raise ConnectionError("Cannot connect to the database:\n%s" % e)
+    return _connection[identity]
 
-def _get_db():
+def _get_db(reconnect=False):
+    """Handles database connections and authentication based on the current
+    identity
+    """
     global _db, _connection
+    identity = get_identity()
     # Connect if not already connected
-    if _connection is None:
-        _connection = _get_connection()
+    if _connection.get(identity) is None or reconnect:
+        _connection[identity] = _get_connection(reconnect=reconnect)
 
-    if _db is None:
+    if _db.get(identity) is None or reconnect:
         # _db_name will be None if the user hasn't called connect()
         if _db_name is None:
             raise ConnectionError('Not connected to the database')
 
         # Get DB from current connection and authenticate if necessary
-        _db = _connection[_db_name]
+        _db[identity] = _connection[identity][_db_name]
         if _db_username and _db_password:
-            _db.authenticate(_db_username, _db_password)
+            _db[identity].authenticate(_db_username, _db_password)
 
-    return _db
+    return _db[identity]
+
+def get_identity():
+    """Creates an identity key based on the current process and thread
+    identity.
+    """
+    identity = multiprocessing.current_process()._identity
+    identity = 0 if not identity else identity[0]
+
+    identity = (identity, threading.current_thread().ident)
+    return identity
 
 def connect(db, username=None, password=None, **kwargs):
-    """Connect to the database specified by the 'db' argument. Connection 
+    """Connect to the database specified by the 'db' argument. Connection
     settings may be provided here as well if the database is not running on
     the default port on localhost. If authentication is needed, provide
     username and password arguments as well.
     """
-    global _connection_settings, _db_name, _db_username, _db_password
-    _connection_settings.update(kwargs)
+    global _connection_settings, _db_name, _db_username, _db_password, _db
+    _connection_settings = dict(_connection_defaults, **kwargs)
     _db_name = db
     _db_username = username
     _db_password = password
+    return _get_db(reconnect=True)
+

mongoengine/dereference.py

@@ -0,0 +1,186 @@
+import operator
+
+import pymongo
+
+from base import BaseDict, BaseList, get_document, TopLevelDocumentMetaclass
+from fields import ReferenceField
+from connection import _get_db
+from queryset import QuerySet
+from document import Document
+
+
+class DeReference(object):
+
+    def __call__(self, items, max_depth=1, instance=None, name=None, get=False):
+        """
+        Cheaply dereferences the items to a set depth.
+        Also handles the convertion of complex data types.
+
+        :param items: The iterable (dict, list, queryset) to be dereferenced.
+        :param max_depth: The maximum depth to recurse to
+        :param instance: The owning instance used for tracking changes by
+            :class:`~mongoengine.base.ComplexBaseField`
+        :param name: The name of the field, used for tracking changes by
+            :class:`~mongoengine.base.ComplexBaseField`
+        :param get: A boolean determining if being called by __get__
+        """
+        if items is None or isinstance(items, basestring):
+            return items
+
+        # cheapest way to convert a queryset to a list
+        # list(queryset) uses a count() query to determine length
+        if isinstance(items, QuerySet):
+            items = [i for i in items]
+
+        self.max_depth = max_depth
+
+        doc_type = None
+        if instance and instance._fields:
+            doc_type = instance._fields[name].field
+
+            if isinstance(doc_type, ReferenceField):
+                doc_type = doc_type.document_type
+                if all([i.__class__ == doc_type for i in items]):
+                    return items
+
+        self.reference_map = self._find_references(items)
+        self.object_map = self._fetch_objects(doc_type=doc_type)
+        return self._attach_objects(items, 0, instance, name, get)
+
+    def _find_references(self, items, depth=0):
+        """
+        Recursively finds all db references to be dereferenced
+
+        :param items: The iterable (dict, list, queryset)
+        :param depth: The current depth of recursion
+        """
+        reference_map = {}
+        if not items:
+            return reference_map
+
+        # Determine the iterator to use
+        if not hasattr(items, 'items'):
+            iterator = enumerate(items)
+        else:
+            iterator = items.iteritems()
+
+        # Recursively find dbreferences
+        for k, item in iterator:
+            if hasattr(item, '_fields'):
+                for field_name, field in item._fields.iteritems():
+                    v = item._data.get(field_name, None)
+                    if isinstance(v, (pymongo.dbref.DBRef)):
+                        reference_map.setdefault(field.document_type, []).append(v.id)
+                    elif isinstance(v, (dict, pymongo.son.SON)) and '_ref' in v:
+                        reference_map.setdefault(get_document(v['_cls']), []).append(v['_ref'].id)
+                    elif isinstance(v, (dict, list, tuple)) and depth <= self.max_depth:
+                        field_cls = getattr(getattr(field, 'field', None), 'document_type', None)
+                        references = self._find_references(v, depth)
+                        for key, refs in references.iteritems():
+                            if isinstance(field_cls, (Document, TopLevelDocumentMetaclass)):
+                                key = field_cls
+                            reference_map.setdefault(key, []).extend(refs)
+            elif isinstance(item, (pymongo.dbref.DBRef)):
+                reference_map.setdefault(item.collection, []).append(item.id)
+            elif isinstance(item, (dict, pymongo.son.SON)) and '_ref' in item:
+                reference_map.setdefault(get_document(item['_cls']), []).append(item['_ref'].id)
+            elif isinstance(item, (dict, list, tuple)) and depth <= self.max_depth:
+                references = self._find_references(item, depth)
+                for key, refs in references.iteritems():
+                    reference_map.setdefault(key, []).extend(refs)
+        depth += 1
+        return reference_map
+
+    def _fetch_objects(self, doc_type=None):
+        """Fetch all references and convert to their document objects
+        """
+        object_map = {}
+        for col, dbrefs in self.reference_map.iteritems():
+            keys = object_map.keys()
+            refs = list(set([dbref for dbref in dbrefs if str(dbref) not in keys]))
+            if hasattr(col, 'objects'):  # We have a document class for the refs
+                references = col.objects.in_bulk(refs)
+                for key, doc in references.iteritems():
+                    object_map[key] = doc
+            else:  # Generic reference: use the refs data to convert to document
+                references = _get_db()[col].find({'_id': {'$in': refs}})
+                for ref in references:
+                    if '_cls' in ref:
+                        doc = get_document(ref['_cls'])._from_son(ref)
+                    else:
+                        doc = doc_type._from_son(ref)
+                    object_map[doc.id] = doc
+        return object_map
+
+    def _attach_objects(self, items, depth=0, instance=None, name=None, get=False):
+        """
+        Recursively finds all db references to be dereferenced
+
+        :param items: The iterable (dict, list, queryset)
+        :param depth: The current depth of recursion
+        :param instance: The owning instance used for tracking changes by
+            :class:`~mongoengine.base.ComplexBaseField`
+        :param name: The name of the field, used for tracking changes by
+            :class:`~mongoengine.base.ComplexBaseField`
+        :param get: A boolean determining if being called by __get__
+        """
+        if not items:
+            if isinstance(items, (BaseDict, BaseList)):
+                return items
+
+            if instance:
+                if isinstance(items, dict):
+                    return BaseDict(items, instance=instance, name=name)
+                else:
+                    return BaseList(items, instance=instance, name=name)
+
+        if isinstance(items, (dict, pymongo.son.SON)):
+            if '_ref' in items:
+                return self.object_map.get(items['_ref'].id, items)
+            elif '_types' in items and '_cls' in items:
+                doc = get_document(items['_cls'])._from_son(items)
+                if not get:
+                    doc._data = self._attach_objects(doc._data, depth, doc, name, get)
+                return doc
+
+        if not hasattr(items, 'items'):
+            is_list = True
+            iterator = enumerate(items)
+            data = []
+        else:
+            is_list = False
+            iterator = items.iteritems()
+            data = {}
+
+        for k, v in iterator:
+            if is_list:
+                data.append(v)
+            else:
+                data[k] = v
+
+            if k in self.object_map:
+                data[k] = self.object_map[k]
+            elif hasattr(v, '_fields'):
+                for field_name, field in v._fields.iteritems():
+                    v = data[k]._data.get(field_name, None)
+                    if isinstance(v, (pymongo.dbref.DBRef)):
+                        data[k]._data[field_name] = self.object_map.get(v.id, v)
+                    elif isinstance(v, (dict, pymongo.son.SON)) and '_ref' in v:
+                        data[k]._data[field_name] = self.object_map.get(v['_ref'].id, v)
+                    elif isinstance(v, dict) and depth < self.max_depth:
+                        data[k]._data[field_name] = self._attach_objects(v, depth, instance=instance, name=name, get=get)
+                    elif isinstance(v, (list, tuple)):
+                        data[k]._data[field_name] = self._attach_objects(v, depth, instance=instance, name=name, get=get)
+            elif isinstance(v, (dict, list, tuple)) and depth < self.max_depth:
+                data[k] = self._attach_objects(v, depth, instance=instance, name=name, get=get)
+            elif hasattr(v, 'id'):
+                data[k] = self.object_map.get(v.id, v)
+
+        if instance and name:
+            if is_list:
+                return BaseList(data, instance=instance, name=name)
+            return BaseDict(data, instance=instance, name=name)
+        depth += 1
+        return data
+
+dereference = DeReference()

mongoengine/django/auth.py

@@ -3,6 +3,7 @@ from mongoengine import *
 from django.utils.hashcompat import md5_constructor, sha_constructor
 from django.utils.encoding import smart_str
 from django.contrib.auth.models import AnonymousUser
+from django.utils.translation import ugettext_lazy as _
 
 import datetime
 
@@ -21,15 +22,41 @@ class User(Document):
     """A User document that aims to mirror most of the API specified by Django
     at http://docs.djangoproject.com/en/dev/topics/auth/#users
     """
-    username = StringField(max_length=30, required=True)
-    first_name = StringField(max_length=30)
-    last_name = StringField(max_length=30)
-    email = StringField()
-    password = StringField(max_length=128)
-    is_staff = BooleanField(default=False)
-    is_active = BooleanField(default=True)
-    is_superuser = BooleanField(default=False)
-    last_login = DateTimeField(default=datetime.datetime.now)
+    username = StringField(max_length=30, required=True,
+                           verbose_name=_('username'),
+                           help_text=_("Required. 30 characters or fewer. Letters, numbers and @/./+/-/_ characters"))
+
+    first_name = StringField(max_length=30,
+                             verbose_name=_('first name'))
+
+    last_name = StringField(max_length=30,
+                            verbose_name=_('last name'))
+    email = EmailField(verbose_name=_('e-mail address'))
+    password = StringField(max_length=128,
+                           verbose_name=_('password'),
+                           help_text=_("Use '[algo]$[salt]$[hexdigest]' or use the <a href=\"password/\">change password form</a>."))
+    is_staff = BooleanField(default=False,
+                            verbose_name=_('staff status'),
+                            help_text=_("Designates whether the user can log into this admin site."))
+    is_active = BooleanField(default=True,
+                             verbose_name=_('active'),
+                             help_text=_("Designates whether this user should be treated as active. Unselect this instead of deleting accounts."))
+    is_superuser = BooleanField(default=False,
+                                verbose_name=_('superuser status'),
+                                help_text=_("Designates that this user has all permissions without explicitly assigning them."))
+    last_login = DateTimeField(default=datetime.datetime.now,
+                               verbose_name=_('last login'))
+    date_joined = DateTimeField(default=datetime.datetime.now,
+                                verbose_name=_('date joined'))
+
+    meta = {
+        'indexes': [
+            {'fields': ['username'], 'unique': True}
+        ]
+    }
+
+    def __unicode__(self):
+        return self.username
 
     def get_full_name(self):
         """Returns the users first and last names, separated by a space.
@@ -53,6 +80,8 @@ class User(Document):
         salt = get_hexdigest(algo, str(random()), str(random()))[:5]
         hash = get_hexdigest(algo, salt, raw_password)
         self.password = '%s$%s$%s' % (algo, salt, hash)
+        self.save()
+        return self
 
     def check_password(self, raw_password):
         """Checks the user's password against a provided password - always use
@@ -68,16 +97,35 @@ class User(Document):
         """Create (and save) a new user with the given username, password and
         email address.
         """
-        user = User(username=username, email=email)
+        now = datetime.datetime.now()
+
+        # Normalize the address by lowercasing the domain part of the email
+        # address.
+        if email is not None:
+            try:
+                email_name, domain_part = email.strip().split('@', 1)
+            except ValueError:
+                pass
+            else:
+                email = '@'.join([email_name, domain_part.lower()])
+
+        user = cls(username=username, email=email, date_joined=now)
         user.set_password(password)
         user.save()
         return user
 
+    def get_and_delete_messages(self):
+        return []
+
 
 class MongoEngineBackend(object):
     """Authenticate using MongoEngine and mongoengine.django.auth.User.
     """
 
+    supports_object_permissions = False
+    supports_anonymous_user = False
+    supports_inactive_user = False
+
     def authenticate(self, username=None, password=None):
         user = User.objects(username=username).first()
         if user:

mongoengine/django/shortcuts.py

@@ -0,0 +1,46 @@
+from django.http import Http404
+from mongoengine.queryset import QuerySet
+from mongoengine.base import BaseDocument
+from mongoengine.base import ValidationError
+
+def _get_queryset(cls):
+    """Inspired by django.shortcuts.*"""
+    if isinstance(cls, QuerySet):
+        return cls
+    else:
+        return cls.objects
+
+def get_document_or_404(cls, *args, **kwargs):
+    """
+    Uses get() to return an document, or raises a Http404 exception if the document
+    does not exist.
+
+    cls may be a Document or QuerySet object. All other passed
+    arguments and keyword arguments are used in the get() query.
+
+    Note: Like with get(), an MultipleObjectsReturned will be raised if more than one
+    object is found.
+
+    Inspired by django.shortcuts.*
+    """
+    queryset = _get_queryset(cls)
+    try:
+        return queryset.get(*args, **kwargs)
+    except (queryset._document.DoesNotExist, ValidationError):
+        raise Http404('No %s matches the given query.' % queryset._document._class_name)
+
+def get_list_or_404(cls, *args, **kwargs):
+    """
+    Uses filter() to return a list of documents, or raise a Http404 exception if
+    the list is empty.
+
+    cls may be a Document or QuerySet object. All other passed
+    arguments and keyword arguments are used in the filter() query.
+
+    Inspired by django.shortcuts.*
+    """
+    queryset = _get_queryset(cls)
+    obj_list = list(queryset.filter(*args, **kwargs))
+    if not obj_list:
+        raise Http404('No %s matches the given query.' % queryset._document._class_name)
+    return obj_list

mongoengine/django/storage.py

@@ -0,0 +1,112 @@
+import os
+import itertools
+import urlparse
+
+from mongoengine import *
+from django.conf import settings
+from django.core.files.storage import Storage
+from django.core.exceptions import ImproperlyConfigured
+
+
+class FileDocument(Document):
+    """A document used to store a single file in GridFS.
+    """
+    file = FileField()
+
+
+class GridFSStorage(Storage):
+    """A custom storage backend to store files in GridFS
+    """
+
+    def __init__(self, base_url=None):
+
+        if base_url is None:
+            base_url = settings.MEDIA_URL
+        self.base_url = base_url
+        self.document = FileDocument
+        self.field = 'file'
+
+    def delete(self, name):
+        """Deletes the specified file from the storage system.
+        """
+        if self.exists(name):
+            doc = self.document.objects.first()
+            field = getattr(doc, self.field)
+            self._get_doc_with_name(name).delete()  # Delete the FileField
+            field.delete()                          # Delete the FileDocument
+
+    def exists(self, name):
+        """Returns True if a file referened by the given name already exists in the
+        storage system, or False if the name is available for a new file.
+        """
+        doc = self._get_doc_with_name(name)
+        if doc:
+            field = getattr(doc, self.field)
+            return bool(field.name)
+        else:
+            return False
+
+    def listdir(self, path=None):
+        """Lists the contents of the specified path, returning a 2-tuple of lists;
+        the first item being directories, the second item being files.
+        """
+        def name(doc):
+            return getattr(doc, self.field).name
+        docs = self.document.objects
+        return [], [name(d) for d in docs if name(d)]
+
+    def size(self, name):
+        """Returns the total size, in bytes, of the file specified by name.
+        """
+        doc = self._get_doc_with_name(name)
+        if doc:
+            return getattr(doc, self.field).length
+        else:
+            raise ValueError("No such file or directory: '%s'" % name)
+
+    def url(self, name):
+        """Returns an absolute URL where the file's contents can be accessed
+        directly by a web browser.
+        """
+        if self.base_url is None:
+            raise ValueError("This file is not accessible via a URL.")
+        return urlparse.urljoin(self.base_url, name).replace('\\', '/')
+
+    def _get_doc_with_name(self, name):
+        """Find the documents in the store with the given name
+        """
+        docs = self.document.objects
+        doc = [d for d in docs if getattr(d, self.field).name == name]
+        if doc:
+            return doc[0]
+        else:
+            return None
+
+    def _open(self, name, mode='rb'):
+        doc = self._get_doc_with_name(name)
+        if doc:
+            return getattr(doc, self.field)
+        else:
+            raise ValueError("No file found with the name '%s'." % name)
+
+    def get_available_name(self, name):
+        """Returns a filename that's free on the target storage system, and
+        available for new content to be written to.
+        """
+        file_root, file_ext = os.path.splitext(name)
+        # If the filename already exists, add an underscore and a number (before
+        # the file extension, if one exists) to the filename until the generated
+        # filename doesn't exist.
+        count = itertools.count(1)
+        while self.exists(name):
+            # file_ext includes the dot.
+            name = os.path.join("%s_%s%s" % (file_root, count.next(), file_ext))
+
+        return name
+
+    def _save(self, name, content):
+        doc = self.document()
+        getattr(doc, self.field).put(content, filename=name)
+        doc.save()
+
+        return name

mongoengine/django/tests.py

@@ -0,0 +1,21 @@
+#coding: utf-8
+from django.test import TestCase
+from django.conf import settings
+
+from mongoengine import connect
+
+class MongoTestCase(TestCase):
+    """
+    TestCase class that clear the collection between the tests
+    """
+    db_name = 'test_%s' % settings.MONGO_DATABASE_NAME
+    def __init__(self, methodName='runtest'):
+        self.db = connect(self.db_name)
+        super(MongoTestCase, self).__init__(methodName)
+
+    def _post_teardown(self):
+        super(MongoTestCase, self)._post_teardown()
+        for collection in self.db.collection_names():
+            if collection == 'system.indexes':
+                continue
+            self.db.drop_collection(collection)

mongoengine/document.py

@@ -1,12 +1,17 @@
+from mongoengine import signals
 from base import (DocumentMetaclass, TopLevelDocumentMetaclass, BaseDocument,
-                  ValidationError)
+                  ValidationError, BaseDict, BaseList)
 from queryset import OperationError
 from connection import _get_db
 
 import pymongo
 
+__all__ = ['Document', 'EmbeddedDocument', 'ValidationError',
+           'OperationError', 'InvalidCollectionError']
 
-__all__ = ['Document', 'EmbeddedDocument', 'ValidationError', 'OperationError']
+
+class InvalidCollectionError(Exception):
+    pass
 
 
 class EmbeddedDocument(BaseDocument):
@@ -15,9 +20,21 @@ class EmbeddedDocument(BaseDocument):
     fields on :class:`~mongoengine.Document`\ s through the
     :class:`~mongoengine.EmbeddedDocumentField` field type.
     """
-    
+
     __metaclass__ = DocumentMetaclass
 
+    def __delattr__(self, *args, **kwargs):
+        """Handle deletions of fields"""
+        field_name = args[0]
+        if field_name in self._fields:
+            default = self._fields[field_name].default
+            if callable(default):
+                default = default()
+            setattr(self, field_name, default)
+        else:
+            super(EmbeddedDocument, self).__delattr__(*args, **kwargs)
+
+
 
 class Document(BaseDocument):
     """The base class used for defining the structure and properties of
@@ -40,62 +57,188 @@ class Document(BaseDocument):
     presence of `_cls` and `_types`, set :attr:`allow_inheritance` to
     ``False`` in the :attr:`meta` dictionary.
 
-    A :class:`~mongoengine.Document` may use a **Capped Collection** by 
+    A :class:`~mongoengine.Document` may use a **Capped Collection** by
     specifying :attr:`max_documents` and :attr:`max_size` in the :attr:`meta`
     dictionary. :attr:`max_documents` is the maximum number of documents that
-    is allowed to be stored in the collection, and :attr:`max_size` is the 
-    maximum size of the collection in bytes. If :attr:`max_size` is not 
-    specified and :attr:`max_documents` is, :attr:`max_size` defaults to 
+    is allowed to be stored in the collection, and :attr:`max_size` is the
+    maximum size of the collection in bytes. If :attr:`max_size` is not
+    specified and :attr:`max_documents` is, :attr:`max_size` defaults to
     10000000 bytes (10MB).
 
     Indexes may be created by specifying :attr:`indexes` in the :attr:`meta`
-    dictionary. The value should be a list of field names or tuples of field 
+    dictionary. The value should be a list of field names or tuples of field
     names. Index direction may be specified by prefixing the field names with
     a **+** or **-** sign.
-    """
 
+    By default, _types will be added to the start of every index (that
+    doesn't contain a list) if allow_inheritence is True. This can be
+    disabled by either setting types to False on the specific index or
+    by setting index_types to False on the meta dictionary for the document.
+    """
     __metaclass__ = TopLevelDocumentMetaclass
 
-    def save(self, safe=True, force_insert=False):
+    @classmethod
+    def _get_collection(self):
+        """Returns the collection for the document."""
+        db = _get_db()
+        collection_name = self._get_collection_name()
+
+        if not hasattr(self, '_collection') or self._collection is None:
+            # Create collection as a capped collection if specified
+            if self._meta['max_size'] or self._meta['max_documents']:
+                # Get max document limit and max byte size from meta
+                max_size = self._meta['max_size'] or 10000000  # 10MB default
+                max_documents = self._meta['max_documents']
+
+                if collection_name in db.collection_names():
+                    self._collection = db[collection_name]
+                    # The collection already exists, check if its capped
+                    # options match the specified capped options
+                    options = self._collection.options()
+                    if options.get('max') != max_documents or \
+                       options.get('size') != max_size:
+                        msg = ('Cannot create collection "%s" as a capped '
+                               'collection as it already exists') % self._collection
+                        raise InvalidCollectionError(msg)
+                else:
+                    # Create the collection as a capped collection
+                    opts = {'capped': True, 'size': max_size}
+                    if max_documents:
+                        opts['max'] = max_documents
+                    self._collection = db.create_collection(
+                        collection_name, **opts
+                    )
+            else:
+                self._collection = db[collection_name]
+        return self._collection
+
+    def save(self, safe=True, force_insert=False, validate=True, write_options=None, _refs=None):
         """Save the :class:`~mongoengine.Document` to the database. If the
         document already exists, it will be updated, otherwise it will be
         created.
 
-        If ``safe=True`` and the operation is unsuccessful, an 
+        If ``safe=True`` and the operation is unsuccessful, an
         :class:`~mongoengine.OperationError` will be raised.
 
         :param safe: check if the operation succeeded before returning
-        :param force_insert: only try to create a new document, don't allow 
+        :param force_insert: only try to create a new document, don't allow
             updates of existing documents
+        :param validate: validates the document; set to ``False`` to skip.
+        :param write_options: Extra keyword arguments are passed down to
+                :meth:`~pymongo.collection.Collection.save` OR
+                :meth:`~pymongo.collection.Collection.insert`
+                which will be used as options for the resultant ``getLastError`` command.
+                For example, ``save(..., w=2, fsync=True)`` will wait until at least two servers
+                have recorded the write and will force an fsync on each server being written to.
+
+        .. versionchanged:: 0.5
+            In existing documents it only saves changed fields using set / unset
+            Saves are cascaded and any :class:`~pymongo.dbref.DBRef` objects
+            that have changes are saved as well.
         """
-        self.validate()
+        from fields import ReferenceField, GenericReferenceField
+
+        signals.pre_save.send(self.__class__, document=self)
+
+        if validate:
+            self.validate()
+
+        if not write_options:
+            write_options = {}
+
         doc = self.to_mongo()
+
+        created = '_id' in doc
+        creation_mode = force_insert or not created
         try:
             collection = self.__class__.objects._collection
-            if force_insert:
-                object_id = collection.insert(doc, safe=safe)
+            if creation_mode:
+                if force_insert:
+                    object_id = collection.insert(doc, safe=safe, **write_options)
+                else:
+                    object_id = collection.save(doc, safe=safe, **write_options)
             else:
-                object_id = collection.save(doc, safe=safe)
+                object_id = doc['_id']
+                updates, removals = self._delta()
+                if updates:
+                    collection.update({'_id': object_id}, {"$set": updates}, upsert=True, safe=safe, **write_options)
+                if removals:
+                    collection.update({'_id': object_id}, {"$unset": removals}, upsert=True, safe=safe, **write_options)
+
+            # Save any references / generic references
+            _refs = _refs or []
+            for name, cls in self._fields.items():
+                if isinstance(cls, (ReferenceField, GenericReferenceField)):
+                    ref = getattr(self, name)
+                    if ref and str(ref) not in _refs:
+                        _refs.append(str(ref))
+                        ref.save(safe=safe, force_insert=force_insert,
+                                 validate=validate, write_options=write_options,
+                                 _refs=_refs)
+
         except pymongo.errors.OperationFailure, err:
             message = 'Could not save document (%s)'
-            if 'duplicate key' in str(err):
-                message = 'Tried to save duplicate unique keys (%s)'
-            raise OperationError(message % str(err))
+            if u'duplicate key' in unicode(err):
+                message = u'Tried to save duplicate unique keys (%s)'
+            raise OperationError(message % unicode(err))
         id_field = self._meta['id_field']
         self[id_field] = self._fields[id_field].to_python(object_id)
 
+        def reset_changed_fields(doc, inspected_docs=None):
+            """Loop through and reset changed fields lists"""
+
+            inspected_docs = inspected_docs or []
+            inspected_docs.append(doc)
+            if hasattr(doc, '_changed_fields'):
+                doc._changed_fields = []
+
+            for field_name in doc._fields:
+                field = getattr(doc, field_name)
+                if field not in inspected_docs and hasattr(field, '_changed_fields'):
+                    reset_changed_fields(field, inspected_docs)
+
+        reset_changed_fields(self)
+        signals.post_save.send(self.__class__, document=self, created=creation_mode)
+
+    def update(self, **kwargs):
+        """Performs an update on the :class:`~mongoengine.Document`
+        A convenience wrapper to :meth:`~mongoengine.QuerySet.update`.
+
+        Raises :class:`OperationError` if called on an object that has not yet
+        been saved.
+        """
+        if not self.pk:
+            raise OperationError('attempt to update a document not yet saved')
+
+        return self.__class__.objects(pk=self.pk).update_one(**kwargs)
+
     def delete(self, safe=False):
         """Delete the :class:`~mongoengine.Document` from the database. This
         will only take effect if the document has been previously saved.
 
         :param safe: check if the operation succeeded before returning
         """
+        signals.pre_delete.send(self.__class__, document=self)
+
         id_field = self._meta['id_field']
         object_id = self._fields[id_field].to_mongo(self[id_field])
         try:
             self.__class__.objects(**{id_field: object_id}).delete(safe=safe)
         except pymongo.errors.OperationFailure, err:
-            raise OperationError('Could not delete document (%s)' % str(err))
+            message = u'Could not delete document (%s)' % err.message
+            raise OperationError(message)
+
+        signals.post_delete.send(self.__class__, document=self)
+
+    def select_related(self, max_depth=1):
+        """Handles dereferencing of :class:`~pymongo.dbref.DBRef` objects to
+        a maximum depth in order to cut down the number queries to mongodb.
+
+        .. versionadded:: 0.5
+        """
+        from dereference import dereference
+        self._data = dereference(self._data, max_depth)
+        return self
 
     def reload(self):
         """Reloads all attributes from the database.
@@ -105,26 +248,37 @@ class Document(BaseDocument):
         id_field = self._meta['id_field']
         obj = self.__class__.objects(**{id_field: self[id_field]}).first()
         for field in self._fields:
-            setattr(self, field, obj[field])
+            setattr(self, field, self._reload(field, obj[field]))
+        self._changed_fields = []
 
-    def validate(self):
-        """Ensure that all fields' values are valid and that required fields
-        are present.
+    def _reload(self, key, value):
+        """Used by :meth:`~mongoengine.Document.reload` to ensure the
+        correct instance is linked to self.
         """
-        # Get a list of tuples of field names and their current values
-        fields = [(field, getattr(self, name)) 
-                  for name, field in self._fields.items()]
+        if isinstance(value, BaseDict):
+            value = [(k, self._reload(k,v)) for k,v in value.items()]
+            value = BaseDict(value, instance=self, name=key)
+        elif isinstance(value, BaseList):
+            value = [self._reload(key, v) for v in value]
+            value = BaseList(value, instance=self, name=key)
+        elif isinstance(value, EmbeddedDocument):
+            value._changed_fields = []
+        return value
 
-        # Ensure that each field is matched to a valid value
-        for field, value in fields:
-            if value is not None:
-                try:
-                    field.validate(value)
-                except (ValueError, AttributeError, AssertionError), e:
-                    raise ValidationError('Invalid value for field of type "' +
-                                          field.__class__.__name__ + '"')
-            elif field.required:
-                raise ValidationError('Field "%s" is required' % field.name)
+    def to_dbref(self):
+        """Returns an instance of :class:`~pymongo.dbref.DBRef` useful in
+        `__raw__` queries."""
+        if not self.pk:
+            msg = "Only saved documents can have a valid dbref"
+            raise OperationError(msg)
+        return pymongo.dbref.DBRef(self.__class__._get_collection_name(), self.pk)
+
+    @classmethod
+    def register_delete_rule(cls, document_cls, field_name, rule):
+        """This method registers the delete rules to apply when removing this
+        object.
+        """
+        cls._meta['delete_rules'][(document_cls, field_name)] = rule
 
     @classmethod
     def drop_collection(cls):
@@ -132,4 +286,44 @@ class Document(BaseDocument):
         :class:`~mongoengine.Document` type from the database.
         """
         db = _get_db()
-        db.drop_collection(cls._meta['collection'])
+        db.drop_collection(cls._get_collection_name())
+
+
+class MapReduceDocument(object):
+    """A document returned from a map/reduce query.
+
+    :param collection: An instance of :class:`~pymongo.Collection`
+    :param key: Document/result key, often an instance of
+                :class:`~pymongo.objectid.ObjectId`. If supplied as
+                an ``ObjectId`` found in the given ``collection``,
+                the object can be accessed via the ``object`` property.
+    :param value: The result(s) for this key.
+
+    .. versionadded:: 0.3
+    """
+
+    def __init__(self, document, collection, key, value):
+        self._document = document
+        self._collection = collection
+        self.key = key
+        self.value = value
+
+    @property
+    def object(self):
+        """Lazy-load the object referenced by ``self.key``. ``self.key``
+        should be the ``primary_key``.
+        """
+        id_field = self._document()._meta['id_field']
+        id_field_type = type(id_field)
+
+        if not isinstance(self.key, id_field_type):
+            try:
+                self.key = id_field_type(self.key)
+            except:
+                raise Exception("Could not cast key as %s" % \
+                                id_field_type.__name__)
+
+        if not hasattr(self, "_key_object"):
+            self._key_object = self._document.objects.with_id(self.key)
+            return self._key_object
+        return self._key_object

mongoengine/signals.py

@@ -0,0 +1,44 @@
+# -*- coding: utf-8 -*-
+
+__all__ = ['pre_init', 'post_init', 'pre_save', 'post_save',
+           'pre_delete', 'post_delete']
+
+signals_available = False
+try:
+    from blinker import Namespace
+    signals_available = True
+except ImportError:
+    class Namespace(object):
+        def signal(self, name, doc=None):
+            return _FakeSignal(name, doc)
+
+    class _FakeSignal(object):
+        """If blinker is unavailable, create a fake class with the same
+        interface that allows sending of signals but will fail with an
+        error on anything else.  Instead of doing anything on send, it
+        will just ignore the arguments and do nothing instead.
+        """
+
+        def __init__(self, name, doc=None):
+            self.name = name
+            self.__doc__ = doc
+
+        def _fail(self, *args, **kwargs):
+            raise RuntimeError('signalling support is unavailable '
+                               'because the blinker library is '
+                               'not installed.')
+        send = lambda *a, **kw: None
+        connect = disconnect = has_receivers_for = receivers_for = \
+            temporarily_connected_to = _fail
+        del _fail
+
+# the namespace for code signals.  If you are not mongoengine code, do
+# not put signals in here.  Create your own namespace instead.
+_signals = Namespace()
+
+pre_init = _signals.signal('pre_init')
+post_init = _signals.signal('post_init')
+pre_save = _signals.signal('pre_save')
+post_save = _signals.signal('post_save')
+pre_delete = _signals.signal('pre_delete')
+post_delete = _signals.signal('post_delete')

mongoengine/tests.py

@@ -0,0 +1,59 @@
+from mongoengine.connection import _get_db
+
+
+class query_counter(object):
+    """ Query_counter contextmanager to get the number of queries. """
+
+    def __init__(self):
+        """ Construct the query_counter. """
+        self.counter = 0
+        self.db = _get_db()
+
+    def __enter__(self):
+        """ On every with block we need to drop the profile collection. """
+        self.db.set_profiling_level(0)
+        self.db.system.profile.drop()
+        self.db.set_profiling_level(2)
+        return self
+
+    def __exit__(self, t, value, traceback):
+        """ Reset the profiling level. """
+        self.db.set_profiling_level(0)
+
+    def __eq__(self, value):
+        """ == Compare querycounter. """
+        return value == self._get_count()
+
+    def __ne__(self, value):
+        """ != Compare querycounter. """
+        return not self.__eq__(value)
+
+    def __lt__(self, value):
+        """ < Compare querycounter. """
+        return self._get_count() < value
+
+    def __le__(self, value):
+        """ <= Compare querycounter. """
+        return self._get_count() <= value
+
+    def __gt__(self, value):
+        """ > Compare querycounter. """
+        return self._get_count() > value
+
+    def __ge__(self, value):
+        """ >= Compare querycounter. """
+        return self._get_count() >= value
+
+    def __int__(self):
+        """ int representation. """
+        return self._get_count()
+
+    def __repr__(self):
+        """ repr query_counter as the number of queries. """
+        return u"%s" % self._get_count()
+
+    def _get_count(self):
+        """ Get the number of queries. """
+        count = self.db.system.profile.find().count() - self.counter
+        self.counter += 1
+        return count

setup.py

@@ -15,7 +15,7 @@ def get_version(version_tuple):
         version = '%s.%s' % (version, version_tuple[2])
     return version
 
-# Dirty hack to get version number from monogengine/__init__.py - we can't 
+# Dirty hack to get version number from monogengine/__init__.py - we can't
 # import it as it depends on PyMongo and PyMongo isn't installed until this
 # file is read
 init = os.path.join(os.path.dirname(__file__), 'mongoengine', '__init__.py')
@@ -47,4 +47,5 @@ setup(name='mongoengine',
       classifiers=CLASSIFIERS,
       install_requires=['pymongo'],
       test_suite='tests',
+      tests_require=['blinker', 'django==1.3']
 )

tests/dereference.py

@@ -0,0 +1,717 @@
+import unittest
+
+from mongoengine import *
+from mongoengine.connection import _get_db
+from mongoengine.tests import query_counter
+
+
+class FieldTest(unittest.TestCase):
+
+    def setUp(self):
+        connect(db='mongoenginetest')
+        self.db = _get_db()
+
+    def test_list_item_dereference(self):
+        """Ensure that DBRef items in ListFields are dereferenced.
+        """
+        class User(Document):
+            name = StringField()
+
+        class Group(Document):
+            members = ListField(ReferenceField(User))
+
+        User.drop_collection()
+        Group.drop_collection()
+
+        for i in xrange(1, 51):
+            user = User(name='user %s' % i)
+            user.save()
+
+        group = Group(members=User.objects)
+        group.save()
+
+        group = Group(members=User.objects)
+        group.save()
+
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+
+            group_obj = Group.objects.first()
+            self.assertEqual(q, 1)
+
+            [m for m in group_obj.members]
+            self.assertEqual(q, 2)
+
+        # Document select_related
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+
+            group_obj = Group.objects.first().select_related()
+            self.assertEqual(q, 2)
+            [m for m in group_obj.members]
+            self.assertEqual(q, 2)
+
+        # Queryset select_related
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+            group_objs = Group.objects.select_related()
+            self.assertEqual(q, 2)
+            for group_obj in group_objs:
+                [m for m in group_obj.members]
+                self.assertEqual(q, 2)
+
+        User.drop_collection()
+        Group.drop_collection()
+
+    def test_recursive_reference(self):
+        """Ensure that ReferenceFields can reference their own documents.
+        """
+        class Employee(Document):
+            name = StringField()
+            boss = ReferenceField('self')
+            friends = ListField(ReferenceField('self'))
+
+        Employee.drop_collection()
+
+        bill = Employee(name='Bill Lumbergh')
+        bill.save()
+
+        michael = Employee(name='Michael Bolton')
+        michael.save()
+
+        samir = Employee(name='Samir Nagheenanajar')
+        samir.save()
+
+        friends = [michael, samir]
+        peter = Employee(name='Peter Gibbons', boss=bill, friends=friends)
+        peter.save()
+
+        Employee(name='Funky Gibbon', boss=bill, friends=friends).save()
+        Employee(name='Funky Gibbon', boss=bill, friends=friends).save()
+        Employee(name='Funky Gibbon', boss=bill, friends=friends).save()
+
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+
+            peter = Employee.objects.with_id(peter.id)
+            self.assertEqual(q, 1)
+
+            peter.boss
+            self.assertEqual(q, 2)
+
+            peter.friends
+            self.assertEqual(q, 3)
+
+        # Document select_related
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+
+            peter = Employee.objects.with_id(peter.id).select_related()
+            self.assertEqual(q, 2)
+
+            self.assertEquals(peter.boss, bill)
+            self.assertEqual(q, 2)
+
+            self.assertEquals(peter.friends, friends)
+            self.assertEqual(q, 2)
+
+        # Queryset select_related
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+
+            employees = Employee.objects(boss=bill).select_related()
+            self.assertEqual(q, 2)
+
+            for employee in employees:
+                self.assertEquals(employee.boss, bill)
+                self.assertEqual(q, 2)
+
+                self.assertEquals(employee.friends, friends)
+                self.assertEqual(q, 2)
+
+    def test_circular_reference(self):
+        """Ensure you can handle circular references
+        """
+        class Person(Document):
+            name = StringField()
+            relations = ListField(EmbeddedDocumentField('Relation'))
+
+            def __repr__(self):
+                return "<Person: %s>" % self.name
+
+        class Relation(EmbeddedDocument):
+            name = StringField()
+            person = ReferenceField('Person')
+
+        Person.drop_collection()
+        mother = Person(name="Mother")
+        daughter = Person(name="Daughter")
+
+        mother.save()
+        daughter.save()
+
+        daughter_rel = Relation(name="Daughter", person=daughter)
+        mother.relations.append(daughter_rel)
+        mother.save()
+
+        mother_rel = Relation(name="Daughter", person=mother)
+        self_rel = Relation(name="Self", person=daughter)
+        daughter.relations.append(mother_rel)
+        daughter.relations.append(self_rel)
+        daughter.save()
+
+        self.assertEquals("[<Person: Mother>, <Person: Daughter>]", "%s" % Person.objects())
+
+    def test_circular_reference_on_self(self):
+        """Ensure you can handle circular references
+        """
+        class Person(Document):
+            name = StringField()
+            relations = ListField(ReferenceField('self'))
+
+            def __repr__(self):
+                return "<Person: %s>" % self.name
+
+        Person.drop_collection()
+        mother = Person(name="Mother")
+        daughter = Person(name="Daughter")
+
+        mother.save()
+        daughter.save()
+
+        mother.relations.append(daughter)
+        mother.save()
+
+        daughter.relations.append(mother)
+        daughter.relations.append(daughter)
+        daughter.save()
+
+        self.assertEquals("[<Person: Mother>, <Person: Daughter>]", "%s" % Person.objects())
+
+    def test_generic_reference(self):
+
+        class UserA(Document):
+            name = StringField()
+
+        class UserB(Document):
+            name = StringField()
+
+        class UserC(Document):
+            name = StringField()
+
+        class Group(Document):
+            members = ListField(GenericReferenceField())
+
+        UserA.drop_collection()
+        UserB.drop_collection()
+        UserC.drop_collection()
+        Group.drop_collection()
+
+        members = []
+        for i in xrange(1, 51):
+            a = UserA(name='User A %s' % i)
+            a.save()
+
+            b = UserB(name='User B %s' % i)
+            b.save()
+
+            c = UserC(name='User C %s' % i)
+            c.save()
+
+            members += [a, b, c]
+
+        group = Group(members=members)
+        group.save()
+
+        group = Group(members=members)
+        group.save()
+
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+
+            group_obj = Group.objects.first()
+            self.assertEqual(q, 1)
+
+            [m for m in group_obj.members]
+            self.assertEqual(q, 4)
+
+            [m for m in group_obj.members]
+            self.assertEqual(q, 4)
+
+            for m in group_obj.members:
+                self.assertTrue('User' in m.__class__.__name__)
+
+        # Document select_related
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+
+            group_obj = Group.objects.first().select_related()
+            self.assertEqual(q, 4)
+
+            [m for m in group_obj.members]
+            self.assertEqual(q, 4)
+
+            [m for m in group_obj.members]
+            self.assertEqual(q, 4)
+
+            for m in group_obj.members:
+                self.assertTrue('User' in m.__class__.__name__)
+
+        # Queryset select_related
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+
+            group_objs = Group.objects.select_related()
+            self.assertEqual(q, 4)
+
+            for group_obj in group_objs:
+                [m for m in group_obj.members]
+                self.assertEqual(q, 4)
+
+                [m for m in group_obj.members]
+                self.assertEqual(q, 4)
+
+                for m in group_obj.members:
+                    self.assertTrue('User' in m.__class__.__name__)
+
+        UserA.drop_collection()
+        UserB.drop_collection()
+        UserC.drop_collection()
+        Group.drop_collection()
+
+    def test_list_field_complex(self):
+
+        class UserA(Document):
+            name = StringField()
+
+        class UserB(Document):
+            name = StringField()
+
+        class UserC(Document):
+            name = StringField()
+
+        class Group(Document):
+            members = ListField()
+
+        UserA.drop_collection()
+        UserB.drop_collection()
+        UserC.drop_collection()
+        Group.drop_collection()
+
+        members = []
+        for i in xrange(1, 51):
+            a = UserA(name='User A %s' % i)
+            a.save()
+
+            b = UserB(name='User B %s' % i)
+            b.save()
+
+            c = UserC(name='User C %s' % i)
+            c.save()
+
+            members += [a, b, c]
+
+        group = Group(members=members)
+        group.save()
+
+        group = Group(members=members)
+        group.save()
+
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+
+            group_obj = Group.objects.first()
+            self.assertEqual(q, 1)
+
+            [m for m in group_obj.members]
+            self.assertEqual(q, 4)
+
+            [m for m in group_obj.members]
+            self.assertEqual(q, 4)
+
+            for m in group_obj.members:
+                self.assertTrue('User' in m.__class__.__name__)
+
+        # Document select_related
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+
+            group_obj = Group.objects.first().select_related()
+            self.assertEqual(q, 4)
+
+            [m for m in group_obj.members]
+            self.assertEqual(q, 4)
+
+            [m for m in group_obj.members]
+            self.assertEqual(q, 4)
+
+            for m in group_obj.members:
+                self.assertTrue('User' in m.__class__.__name__)
+
+        # Queryset select_related
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+
+            group_objs = Group.objects.select_related()
+            self.assertEqual(q, 4)
+
+            for group_obj in group_objs:
+                [m for m in group_obj.members]
+                self.assertEqual(q, 4)
+
+                [m for m in group_obj.members]
+                self.assertEqual(q, 4)
+
+                for m in group_obj.members:
+                    self.assertTrue('User' in m.__class__.__name__)
+
+        UserA.drop_collection()
+        UserB.drop_collection()
+        UserC.drop_collection()
+        Group.drop_collection()
+
+    def test_map_field_reference(self):
+
+        class User(Document):
+            name = StringField()
+
+        class Group(Document):
+            members = MapField(ReferenceField(User))
+
+        User.drop_collection()
+        Group.drop_collection()
+
+        members = []
+        for i in xrange(1, 51):
+            user = User(name='user %s' % i)
+            user.save()
+            members.append(user)
+
+        group = Group(members=dict([(str(u.id), u) for u in members]))
+        group.save()
+
+        group = Group(members=dict([(str(u.id), u) for u in members]))
+        group.save()
+
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+
+            group_obj = Group.objects.first()
+            self.assertEqual(q, 1)
+
+            [m for m in group_obj.members]
+            self.assertEqual(q, 2)
+
+            for k, m in group_obj.members.iteritems():
+                self.assertTrue(isinstance(m, User))
+
+        # Document select_related
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+
+            group_obj = Group.objects.first().select_related()
+            self.assertEqual(q, 2)
+
+            [m for m in group_obj.members]
+            self.assertEqual(q, 2)
+
+            for k, m in group_obj.members.iteritems():
+                self.assertTrue(isinstance(m, User))
+
+       # Queryset select_related
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+
+            group_objs = Group.objects.select_related()
+            self.assertEqual(q, 2)
+
+            for group_obj in group_objs:
+                [m for m in group_obj.members]
+                self.assertEqual(q, 2)
+
+                for k, m in group_obj.members.iteritems():
+                    self.assertTrue(isinstance(m, User))
+
+        User.drop_collection()
+        Group.drop_collection()
+
+    def test_dict_field(self):
+
+        class UserA(Document):
+            name = StringField()
+
+        class UserB(Document):
+            name = StringField()
+
+        class UserC(Document):
+            name = StringField()
+
+        class Group(Document):
+            members = DictField()
+
+        UserA.drop_collection()
+        UserB.drop_collection()
+        UserC.drop_collection()
+        Group.drop_collection()
+
+        members = []
+        for i in xrange(1, 51):
+            a = UserA(name='User A %s' % i)
+            a.save()
+
+            b = UserB(name='User B %s' % i)
+            b.save()
+
+            c = UserC(name='User C %s' % i)
+            c.save()
+
+            members += [a, b, c]
+
+        group = Group(members=dict([(str(u.id), u) for u in members]))
+        group.save()
+        group = Group(members=dict([(str(u.id), u) for u in members]))
+        group.save()
+
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+
+            group_obj = Group.objects.first()
+            self.assertEqual(q, 1)
+
+            [m for m in group_obj.members]
+            self.assertEqual(q, 4)
+
+            [m for m in group_obj.members]
+            self.assertEqual(q, 4)
+
+            for k, m in group_obj.members.iteritems():
+                self.assertTrue('User' in m.__class__.__name__)
+
+        # Document select_related
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+
+            group_obj = Group.objects.first().select_related()
+            self.assertEqual(q, 4)
+
+            [m for m in group_obj.members]
+            self.assertEqual(q, 4)
+
+            [m for m in group_obj.members]
+            self.assertEqual(q, 4)
+
+            for k, m in group_obj.members.iteritems():
+                self.assertTrue('User' in m.__class__.__name__)
+
+        # Queryset select_related
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+
+            group_objs = Group.objects.select_related()
+            self.assertEqual(q, 4)
+
+            for group_obj in group_objs:
+                [m for m in group_obj.members]
+                self.assertEqual(q, 4)
+
+                [m for m in group_obj.members]
+                self.assertEqual(q, 4)
+
+                for k, m in group_obj.members.iteritems():
+                    self.assertTrue('User' in m.__class__.__name__)
+
+        Group.objects.delete()
+        Group().save()
+
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+
+            group_obj = Group.objects.first()
+            self.assertEqual(q, 1)
+
+            [m for m in group_obj.members]
+            self.assertEqual(q, 1)
+            self.assertEqual(group_obj.members, {})
+
+        UserA.drop_collection()
+        UserB.drop_collection()
+        UserC.drop_collection()
+        Group.drop_collection()
+
+    def test_dict_field_no_field_inheritance(self):
+
+        class UserA(Document):
+            name = StringField()
+            meta = {'allow_inheritance': False}
+
+        class Group(Document):
+            members = DictField()
+
+        UserA.drop_collection()
+        Group.drop_collection()
+
+        members = []
+        for i in xrange(1, 51):
+            a = UserA(name='User A %s' % i)
+            a.save()
+
+            members += [a]
+
+        group = Group(members=dict([(str(u.id), u) for u in members]))
+        group.save()
+
+        group = Group(members=dict([(str(u.id), u) for u in members]))
+        group.save()
+
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+
+            group_obj = Group.objects.first()
+            self.assertEqual(q, 1)
+
+            [m for m in group_obj.members]
+            self.assertEqual(q, 2)
+
+            [m for m in group_obj.members]
+            self.assertEqual(q, 2)
+
+            for k, m in group_obj.members.iteritems():
+                self.assertTrue(isinstance(m, UserA))
+
+        # Document select_related
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+
+            group_obj = Group.objects.first().select_related()
+            self.assertEqual(q, 2)
+
+            [m for m in group_obj.members]
+            self.assertEqual(q, 2)
+
+            [m for m in group_obj.members]
+            self.assertEqual(q, 2)
+
+            for k, m in group_obj.members.iteritems():
+                self.assertTrue(isinstance(m, UserA))
+
+        # Queryset select_related
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+
+            group_objs = Group.objects.select_related()
+            self.assertEqual(q, 2)
+
+            for group_obj in group_objs:
+                [m for m in group_obj.members]
+                self.assertEqual(q, 2)
+
+                [m for m in group_obj.members]
+                self.assertEqual(q, 2)
+
+                for k, m in group_obj.members.iteritems():
+                    self.assertTrue(isinstance(m, UserA))
+
+        UserA.drop_collection()
+        Group.drop_collection()
+
+    def test_generic_reference_map_field(self):
+
+        class UserA(Document):
+            name = StringField()
+
+        class UserB(Document):
+            name = StringField()
+
+        class UserC(Document):
+            name = StringField()
+
+        class Group(Document):
+            members = MapField(GenericReferenceField())
+
+        UserA.drop_collection()
+        UserB.drop_collection()
+        UserC.drop_collection()
+        Group.drop_collection()
+
+        members = []
+        for i in xrange(1, 51):
+            a = UserA(name='User A %s' % i)
+            a.save()
+
+            b = UserB(name='User B %s' % i)
+            b.save()
+
+            c = UserC(name='User C %s' % i)
+            c.save()
+
+            members += [a, b, c]
+
+        group = Group(members=dict([(str(u.id), u) for u in members]))
+        group.save()
+        group = Group(members=dict([(str(u.id), u) for u in members]))
+        group.save()
+
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+
+            group_obj = Group.objects.first()
+            self.assertEqual(q, 1)
+
+            [m for m in group_obj.members]
+            self.assertEqual(q, 4)
+
+            [m for m in group_obj.members]
+            self.assertEqual(q, 4)
+
+            for k, m in group_obj.members.iteritems():
+                self.assertTrue('User' in m.__class__.__name__)
+
+        # Document select_related
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+
+            group_obj = Group.objects.first().select_related()
+            self.assertEqual(q, 4)
+
+            [m for m in group_obj.members]
+            self.assertEqual(q, 4)
+
+            [m for m in group_obj.members]
+            self.assertEqual(q, 4)
+
+            for k, m in group_obj.members.iteritems():
+                self.assertTrue('User' in m.__class__.__name__)
+
+        # Queryset select_related
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+
+            group_objs = Group.objects.select_related()
+            self.assertEqual(q, 4)
+
+            for group_obj in group_objs:
+                [m for m in group_obj.members]
+                self.assertEqual(q, 4)
+
+                [m for m in group_obj.members]
+                self.assertEqual(q, 4)
+
+                for k, m in group_obj.members.iteritems():
+                    self.assertTrue('User' in m.__class__.__name__)
+
+        Group.objects.delete()
+        Group().save()
+
+        with query_counter() as q:
+            self.assertEqual(q, 0)
+
+            group_obj = Group.objects.first()
+            self.assertEqual(q, 1)
+
+            [m for m in group_obj.members]
+            self.assertEqual(q, 1)
+
+        UserA.drop_collection()
+        UserB.drop_collection()
+        UserC.drop_collection()
+        Group.drop_collection()

tests/django_tests.py

@@ -0,0 +1,69 @@
+# -*- coding: utf-8 -*-
+
+import unittest
+
+from mongoengine import *
+from mongoengine.django.shortcuts import get_document_or_404
+
+from django.http import Http404
+from django.template import Context, Template
+from django.conf import settings
+settings.configure()
+
+class QuerySetTest(unittest.TestCase):
+
+    def setUp(self):
+        connect(db='mongoenginetest')
+
+        class Person(Document):
+            name = StringField()
+            age = IntField()
+        self.Person = Person
+
+    def test_order_by_in_django_template(self):
+        """Ensure that QuerySets are properly ordered in Django template.
+        """
+        self.Person.drop_collection()
+
+        self.Person(name="A", age=20).save()
+        self.Person(name="D", age=10).save()
+        self.Person(name="B", age=40).save()
+        self.Person(name="C", age=30).save()
+
+        t = Template("{% for o in ol %}{{ o.name }}-{{ o.age }}:{% endfor %}")
+
+        d = {"ol": self.Person.objects.order_by('-name')}
+        self.assertEqual(t.render(Context(d)), u'D-10:C-30:B-40:A-20:')
+        d = {"ol": self.Person.objects.order_by('+name')}
+        self.assertEqual(t.render(Context(d)), u'A-20:B-40:C-30:D-10:')
+        d = {"ol": self.Person.objects.order_by('-age')}
+        self.assertEqual(t.render(Context(d)), u'B-40:C-30:A-20:D-10:')
+        d = {"ol": self.Person.objects.order_by('+age')}
+        self.assertEqual(t.render(Context(d)), u'D-10:A-20:C-30:B-40:')
+
+        self.Person.drop_collection()
+
+    def test_q_object_filter_in_template(self):
+
+        self.Person.drop_collection()
+
+        self.Person(name="A", age=20).save()
+        self.Person(name="D", age=10).save()
+        self.Person(name="B", age=40).save()
+        self.Person(name="C", age=30).save()
+
+        t = Template("{% for o in ol %}{{ o.name }}-{{ o.age }}:{% endfor %}")
+
+        d = {"ol": self.Person.objects.filter(Q(age=10) | Q(name="C"))}
+        self.assertEqual(t.render(Context(d)), 'D-10:C-30:')
+
+        # Check double rendering doesn't throw an error
+        self.assertEqual(t.render(Context(d)), 'D-10:C-30:')
+
+    def test_get_document_or_404(self):
+        p = self.Person(name="G404")
+        p.save()
+
+        self.assertRaises(Http404, get_document_or_404, self.Person, pk='1234')
+        self.assertEqual(p, get_document_or_404(self.Person, pk=p.pk))
+

tests/fixtures.py

@@ -0,0 +1,25 @@
+from datetime import datetime
+import pymongo
+
+from mongoengine import *
+from mongoengine.base import BaseField
+from mongoengine.connection import _get_db
+
+
+class PickleEmbedded(EmbeddedDocument):
+    date = DateTimeField(default=datetime.now)
+
+
+class PickleTest(Document):
+    number = IntField()
+    string = StringField(choices=(('One', '1'), ('Two', '2')))
+    embedded = EmbeddedDocumentField(PickleEmbedded)
+    lists = ListField(StringField())
+
+
+class Mixin(object):
+    name = StringField()
+
+
+class Base(Document):
+    pass

tests/signals.py

@@ -0,0 +1,181 @@
+# -*- coding: utf-8 -*-
+import unittest
+
+from mongoengine import *
+from mongoengine import signals
+
+signal_output = []
+
+
+class SignalTests(unittest.TestCase):
+    """
+    Testing signals before/after saving and deleting.
+    """
+
+    def get_signal_output(self, fn, *args, **kwargs):
+        # Flush any existing signal output
+        global signal_output
+        signal_output = []
+        fn(*args, **kwargs)
+        return signal_output
+
+    def setUp(self):
+        connect(db='mongoenginetest')
+        class Author(Document):
+            name = StringField()
+
+            def __unicode__(self):
+                return self.name
+
+            @classmethod
+            def pre_init(cls, sender, document, *args, **kwargs):
+                signal_output.append('pre_init signal, %s' % cls.__name__)
+                signal_output.append(str(kwargs['values']))
+
+            @classmethod
+            def post_init(cls, sender, document, **kwargs):
+                signal_output.append('post_init signal, %s' % document)
+
+            @classmethod
+            def pre_save(cls, sender, document, **kwargs):
+                signal_output.append('pre_save signal, %s' % document)
+
+            @classmethod
+            def post_save(cls, sender, document, **kwargs):
+                signal_output.append('post_save signal, %s' % document)
+                if 'created' in kwargs:
+                    if kwargs['created']:
+                        signal_output.append('Is created')
+                    else:
+                        signal_output.append('Is updated')
+
+            @classmethod
+            def pre_delete(cls, sender, document, **kwargs):
+                signal_output.append('pre_delete signal, %s' % document)
+
+            @classmethod
+            def post_delete(cls, sender, document, **kwargs):
+                signal_output.append('post_delete signal, %s' % document)
+        self.Author = Author
+
+
+        class Another(Document):
+            name = StringField()
+
+            def __unicode__(self):
+                return self.name
+
+            @classmethod
+            def pre_init(cls, sender, document, **kwargs):
+                signal_output.append('pre_init Another signal, %s' % cls.__name__)
+                signal_output.append(str(kwargs['values']))
+
+            @classmethod
+            def post_init(cls, sender, document, **kwargs):
+                signal_output.append('post_init Another signal, %s' % document)
+
+            @classmethod
+            def pre_save(cls, sender, document, **kwargs):
+                signal_output.append('pre_save Another signal, %s' % document)
+
+            @classmethod
+            def post_save(cls, sender, document, **kwargs):
+                signal_output.append('post_save Another signal, %s' % document)
+                if 'created' in kwargs:
+                    if kwargs['created']:
+                        signal_output.append('Is created')
+                    else:
+                        signal_output.append('Is updated')
+
+            @classmethod
+            def pre_delete(cls, sender, document, **kwargs):
+                signal_output.append('pre_delete Another signal, %s' % document)
+
+            @classmethod
+            def post_delete(cls, sender, document, **kwargs):
+                signal_output.append('post_delete Another signal, %s' % document)
+
+        self.Another = Another
+        # Save up the number of connected signals so that we can check at the end
+        # that all the signals we register get properly unregistered
+        self.pre_signals = (
+            len(signals.pre_init.receivers),
+            len(signals.post_init.receivers),
+            len(signals.pre_save.receivers),
+            len(signals.post_save.receivers),
+            len(signals.pre_delete.receivers),
+            len(signals.post_delete.receivers)
+        )
+
+        signals.pre_init.connect(Author.pre_init, sender=Author)
+        signals.post_init.connect(Author.post_init, sender=Author)
+        signals.pre_save.connect(Author.pre_save, sender=Author)
+        signals.post_save.connect(Author.post_save, sender=Author)
+        signals.pre_delete.connect(Author.pre_delete, sender=Author)
+        signals.post_delete.connect(Author.post_delete, sender=Author)
+
+        signals.pre_init.connect(Another.pre_init, sender=Another)
+        signals.post_init.connect(Another.post_init, sender=Another)
+        signals.pre_save.connect(Another.pre_save, sender=Another)
+        signals.post_save.connect(Another.post_save, sender=Another)
+        signals.pre_delete.connect(Another.pre_delete, sender=Another)
+        signals.post_delete.connect(Another.post_delete, sender=Another)
+
+    def tearDown(self):
+        signals.pre_init.disconnect(self.Author.pre_init)
+        signals.post_init.disconnect(self.Author.post_init)
+        signals.post_delete.disconnect(self.Author.post_delete)
+        signals.pre_delete.disconnect(self.Author.pre_delete)
+        signals.post_save.disconnect(self.Author.post_save)
+        signals.pre_save.disconnect(self.Author.pre_save)
+
+        signals.pre_init.disconnect(self.Another.pre_init)
+        signals.post_init.disconnect(self.Another.post_init)
+        signals.post_delete.disconnect(self.Another.post_delete)
+        signals.pre_delete.disconnect(self.Another.pre_delete)
+        signals.post_save.disconnect(self.Another.post_save)
+        signals.pre_save.disconnect(self.Another.pre_save)
+
+        # Check that all our signals got disconnected properly.
+        post_signals = (
+            len(signals.pre_init.receivers),
+            len(signals.post_init.receivers),
+            len(signals.pre_save.receivers),
+            len(signals.post_save.receivers),
+            len(signals.pre_delete.receivers),
+            len(signals.post_delete.receivers)
+        )
+
+        self.assertEqual(self.pre_signals, post_signals)
+
+    def test_model_signals(self):
+        """ Model saves should throw some signals. """
+
+        def create_author():
+            a1 = self.Author(name='Bill Shakespeare')
+
+        self.assertEqual(self.get_signal_output(create_author), [
+            "pre_init signal, Author",
+            "{'name': 'Bill Shakespeare'}",
+            "post_init signal, Bill Shakespeare",
+        ])
+
+        a1 = self.Author(name='Bill Shakespeare')
+        self.assertEqual(self.get_signal_output(a1.save), [
+            "pre_save signal, Bill Shakespeare",
+            "post_save signal, Bill Shakespeare",
+            "Is created"
+        ])
+
+        a1.reload()
+        a1.name='William Shakespeare'
+        self.assertEqual(self.get_signal_output(a1.save), [
+            "pre_save signal, William Shakespeare",
+            "post_save signal, William Shakespeare",
+            "Is updated"
+        ])
+
+        self.assertEqual(self.get_signal_output(a1.delete), [
+            'pre_delete signal, William Shakespeare',
+            'post_delete signal, William Shakespeare',
+        ])