Initial commit

mongomap/document.py

@@ -0,0 +1,68 @@
+import pymongo
+
+import fields
+
+class DocumentMetaclass(type):
+    """Metaclass for all documents.
+    """
+
+    def __new__(cls, name, bases, attrs):
+        doc_fields = {}
+
+        # Include all fields present in superclasses
+        for base in bases:
+            if hasattr(base, '_fields'):
+                doc_fields.update(base._fields)
+
+        # Add the document's fields to the _fields attribute
+        for attr_name, attr_val in attrs.items():
+            if issubclass(attr_val.__class__, fields.Field):
+                if not attr_val.name:
+                    attr_val.name = attr_name
+                doc_fields[attr_name] = attr_val
+        attrs['_fields'] = doc_fields
+
+        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 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 Document(object):
+
+    __metaclass__ = TopLevelDocumentMetaclass
+
+    def __init__(self, **values):
+        self._data = {}
+        # Assign initial values to instance
+        for attr_name, attr_value in self._fields.items():
+            if attr_name in values:
+                setattr(self, attr_name, values.pop(attr_name))
+            else:
+                # Use default value
+                setattr(self, attr_name, getattr(self, attr_name))
+
+    def __iter__(self):
+        # 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)