Created ObjectIdField, removed object_id field parameter

mongomap/base.py

@@ -1,5 +1,7 @@
 from collection import CollectionManager
 
+import pymongo
+
 
 class ValidationError(Exception):
     pass
@@ -65,6 +67,25 @@ class BaseField(object):
         pass
 
 
+class ObjectIdField(BaseField):
+    """An field wrapper around MongoDB's ObjectIds.
+    """
+    
+    def _to_python(self, value):
+        return str(value)
+
+    def _to_mongo(self, value):
+        if not isinstance(value, pymongo.objectid.ObjectId):
+            return pymongo.objectid.ObjectId(value)
+        return value
+
+    def _validate(self, value):
+        try:
+            pymongo.objectid.ObjectId(str(value))
+        except:
+            raise ValidationError('Invalid Object ID')
+
+
 class DocumentMetaclass(type):
     """Metaclass for all documents.
     """
@@ -76,7 +97,6 @@ class DocumentMetaclass(type):
             return super_new(cls, name, bases, attrs)
 
         doc_fields = {}
-
         # Include all fields present in superclasses
         for base in bases:
             if hasattr(base, '_fields'):
@@ -85,7 +105,6 @@ class DocumentMetaclass(type):
         # Add the document's fields to the _fields attribute
         for attr_name, attr_value in attrs.items():
             if issubclass(attr_value.__class__, BaseField):
-                #print attr_value.name
                 if not attr_value.name:
                     attr_value.name = attr_name
                 doc_fields[attr_name] = attr_value
@@ -114,22 +133,15 @@ class TopLevelDocumentMetaclass(DocumentMetaclass):
         for base in bases:
             if hasattr(base, '_meta') and 'collection' in base._meta:
                 collection = base._meta['collection']
-        
-        # Get primary key field
-        object_id_field = None
-        for attr_name, attr_value in attrs.items():
-            if issubclass(attr_value.__class__, BaseField):
-                if hasattr(attr_value, 'object_id') and attr_value.object_id:
-                    object_id_field = attr_name
-                    attr_value.required = True
 
         meta = {
             'collection': collection,
-            'object_id_field': object_id_field,
         }
         meta.update(attrs.get('meta', {}))
         attrs['_meta'] = meta
 
+        attrs['_id'] = ObjectIdField()
+
         # Set up collection manager, needs the class to have fields so use
         # DocumentMetaclass before instantiating CollectionManager object
         new_class = super_new(cls, name, bases, attrs)

mongomap/collection.py

@@ -10,7 +10,6 @@ class CollectionManager(object):
         self._collection_name = document._meta['collection']
         # This will create the collection if it doesn't exist
         self._collection = db[self._collection_name]
-        self._id_field = document._meta['object_id_field']
 
     def _save_document(self, document):
         """Save the provided document to the collection.

mongomap/fields.py

@@ -1,20 +1,20 @@
-from base import BaseField, ValidationError
+from base import BaseField, ObjectIdField, ValidationError
 from document import EmbeddedDocument
  
 import re
+import pymongo
 
 
 __all__ = ['StringField', 'IntField', 'EmbeddedDocumentField', 
-           'ValidationError']
+           'ObjectIdField', 'ValidationError']
 
 
 class StringField(BaseField):
     """A unicode string field.
     """
     
-    def __init__(self, regex=None, max_length=None, object_id=False, **kwargs):
+    def __init__(self, regex=None, max_length=None, **kwargs):
         self.regex = re.compile(regex) if regex else None
-        self.object_id = object_id
         self.max_length = max_length
         super(StringField, self).__init__(**kwargs)