Added dictionary-style access to documents

Added __init__.py info to package, moved TopLevelDocumentMetaclass
to base.py, added tests for dictionary-style access.

mongomap/__init__.py

@@ -0,0 +1,8 @@
+from document import Document
+import fields
+from fields import *
+
+__all__ = fields.__all__  + ['Document']
+
+__author__ = 'Harry Marr'
+__version__ = '0.1'

mongomap/base.py

@@ -65,6 +65,10 @@ class DocumentMetaclass(type):
     """
 
     def __new__(cls, name, bases, attrs):
+        metaclass = attrs.get('__metaclass__')
+        if metaclass and issubclass(metaclass, DocumentMetaclass):
+            return type.__new__(cls, name, bases, attrs)
+
         doc_fields = {}
 
         # Include all fields present in superclasses
@@ -83,6 +87,31 @@ class DocumentMetaclass(type):
         return type.__new__(cls, name, bases, attrs)
 
 
+class TopLevelDocumentMetaclass(DocumentMetaclass):
+    """Metaclass for top-level documents (i.e. documents that have their own
+    collection in the database.
+    """
+
+    def __new__(cls, name, bases, attrs):
+        # Classes defined in this package are abstract and should not have 
+        # their own metadata with DB collection, etc.
+        if attrs.get('__metaclass__') == TopLevelDocumentMetaclass:
+            return DocumentMetaclass.__new__(cls, name, bases, attrs)
+
+        collection = name.lower()
+        # Subclassed documents inherit collection from superclass
+        for base in bases:
+            if hasattr(base, '_meta') and 'collection' in base._meta:
+                collection = base._meta['collection']
+
+        meta = {
+            'collection': collection,
+        }
+        meta.update(attrs.get('meta', {}))
+        attrs['_meta'] = meta
+        return DocumentMetaclass.__new__(cls, name, bases, attrs)
+
+
 class BaseDocument(object):
 
     def __init__(self, **values):
@@ -99,3 +128,19 @@ class BaseDocument(object):
         # Use _data rather than _fields as iterator only looks at names so
         # values don't need to be converted to Python types
         return iter(self._data)
+
+    def __getitem__(self, name):
+        """Dictionary-style field access, return a field's value if present.
+        """
+        try:
+            return getattr(self, name)
+        except AttributeError:
+            raise KeyError(name)
+
+    def __setitem__(self, name, value):
+        """Dictionary-style field access, set a field's value.
+        """
+            # Ensure that the field exists before settings its value
+        if name not in self._fields:
+            raise KeyError(name)
+        return setattr(self, name, value)

mongomap/document.py

@@ -1,30 +1,7 @@
-from base import DocumentMetaclass, BaseDocument
+from base import DocumentMetaclass, TopLevelDocumentMetaclass, BaseDocument
 
 #import pymongo
 
-class TopLevelDocumentMetaclass(DocumentMetaclass):
-    """Metaclass for top-level documents (i.e. documents that have their own
-    collection in the database.
-    """
-
-    def __new__(cls, name, bases, attrs):
-        # Classes defined in this module are abstract and should not have 
-        # their own metadata with DB collection, etc.
-        if attrs['__module__'] != __name__:
-            collection = name.lower()
-            # Subclassed documents inherit collection from superclass
-            for base in bases:
-                if hasattr(base, '_meta') and 'collection' in base._meta:
-                    collection = base._meta['collection']
-
-            meta = {
-                'collection': collection,
-            }
-            meta.update(attrs.get('meta', {}))
-            attrs['_meta'] = meta
-        return DocumentMetaclass.__new__(cls, name, bases, attrs)
-
-
 class EmbeddedDocument(BaseDocument):
     
     __metaclass__ = DocumentMetaclass

tests/document.py

@@ -1,10 +1,15 @@
 import unittest
 
-from mongomap.document import Document
-from mongomap.fields import StringField, IntField
+from mongomap import Document, StringField, IntField
 
 
 class DocumentTest(unittest.TestCase):
+    
+    def setUp(self):
+        class Person(Document):
+            name = StringField()
+            age = IntField()
+        self.Person = Person
 
     def test_definition(self):
         """Ensure that document may be defined using fields.
@@ -23,32 +28,40 @@ class DocumentTest(unittest.TestCase):
         # Test iteration over fields
         fields = list(Person())
         self.assertTrue('name' in fields and 'age' in fields)
+        # Ensure Document isn't treated like an actual document
+        self.assertFalse(hasattr(Document, '_fields'))
 
     def test_inheritance(self):
         """Ensure that document may inherit fields from a superclass document.
         """
-        class Person(Document):
-            name = StringField()
-
-        class Employee(Person):
+        class Employee(self.Person):
             salary = IntField()
 
         self.assertTrue('name' in Employee._fields)
         self.assertTrue('salary' in Employee._fields)
         self.assertEqual(Employee._meta['collection'], 
-                         Person._meta['collection'])
+                         self.Person._meta['collection'])
 
     def test_creation(self):
         """Ensure that document may be created using keyword arguments.
         """
-        class Person(Document):
-            name = StringField()
-            age = IntField()
-        
-        person = Person(name="Test User", age=30)
+        person = self.Person(name="Test User", age=30)
         self.assertEqual(person.name, "Test User")
         self.assertEqual(person.age, 30)
 
+    def test_dictionary_access(self):
+        """Ensure that dictionary-style field access works properly.
+        """
+        person = self.Person(name='Test User', age=30)
+        self.assertEquals(person['name'], 'Test User')
+
+        self.assertRaises(KeyError, person.__getitem__, 'salary')
+        self.assertRaises(KeyError, person.__setitem__, 'salary', 50)
+
+        person['name'] = 'Another User'
+        self.assertEquals(person['name'], 'Another User')
+
+
 
 if __name__ == '__main__':
     unittest.main()

tests/fields.py

@@ -1,7 +1,6 @@
 import unittest
 
-from mongomap.document import Document
-from mongomap.fields import *
+from mongomap import *
 
 
 class FieldTest(unittest.TestCase):