Added required fields, StringFields may be '_id's

Included tests for required fields (checks primary key is required
as well).

Switched from using SuperClass.__init__ to super().

Added constructor for EmbeddedDocumentField.

mongomap/base.py

@@ -8,8 +8,9 @@ class BaseField(object):
     may be added to subclasses of `Document` to define a document's schema.
     """
     
-    def __init__(self, name=None, default=None):
+    def __init__(self, name=None, required=False, default=None):
         self.name = name
+        self.required = required
         self.default = default
 
     def __get__(self, instance, owner):
@@ -42,6 +43,8 @@ class BaseField(object):
             except ValueError:
                 raise ValidationError('Invalid value for field of type "' +
                                       self.__class__.__name__ + '"')
+        elif self.required:
+            raise ValidationError('Field "%s" is required' % self.name)
         instance._data[self.name] = value
 
     def _to_python(self, value):
@@ -66,8 +69,9 @@ class DocumentMetaclass(type):
 
     def __new__(cls, name, bases, attrs):
         metaclass = attrs.get('__metaclass__')
+        super_new =  super(DocumentMetaclass, cls).__new__
         if metaclass and issubclass(metaclass, DocumentMetaclass):
-            return type.__new__(cls, name, bases, attrs)
+            return super_new(cls, name, bases, attrs)
 
         doc_fields = {}
 
@@ -77,14 +81,15 @@ class DocumentMetaclass(type):
                 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__, BaseField):
-                if not attr_val.name:
-                    attr_val.name = attr_name
-                doc_fields[attr_name] = attr_val
+        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
         attrs['_fields'] = doc_fields
 
-        return type.__new__(cls, name, bases, attrs)
+        return super_new(cls, name, bases, attrs)
 
 
 class TopLevelDocumentMetaclass(DocumentMetaclass):
@@ -95,8 +100,9 @@ class TopLevelDocumentMetaclass(DocumentMetaclass):
     def __new__(cls, name, bases, attrs):
         # Classes defined in this package are abstract and should not have 
         # their own metadata with DB collection, etc.
+        super_new =  super(TopLevelDocumentMetaclass, cls).__new__
         if attrs.get('__metaclass__') == TopLevelDocumentMetaclass:
-            return DocumentMetaclass.__new__(cls, name, bases, attrs)
+            return super_new(cls, name, bases, attrs)
 
         collection = name.lower()
         # Subclassed documents inherit collection from superclass
@@ -104,12 +110,21 @@ class TopLevelDocumentMetaclass(DocumentMetaclass):
             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
-        return DocumentMetaclass.__new__(cls, name, bases, attrs)
+        return super_new(cls, name, bases, attrs)
 
 
 class BaseDocument(object):
@@ -121,6 +136,8 @@ class BaseDocument(object):
             if attr_name in values:
                 setattr(self, attr_name, values.pop(attr_name))
             else:
+                if attr_value.required:
+                    raise ValidationError('Field "%s" is required' % self.name)
                 # Use default value
                 setattr(self, attr_name, getattr(self, attr_name))
 

mongomap/fields.py

@@ -11,10 +11,11 @@ class StringField(BaseField):
     """A unicode string field.
     """
     
-    def __init__(self, regex=None, max_length=None, **kwargs):
+    def __init__(self, regex=None, max_length=None, object_id=False, **kwargs):
         self.regex = re.compile(regex) if regex else None
+        self.object_id = object_id
         self.max_length = max_length
-        BaseField.__init__(self, **kwargs)
+        super(StringField, self).__init__(**kwargs)
 
     def _validate(self, value):
         if self.max_length is not None and len(value) > self.max_length:
@@ -31,7 +32,7 @@ class IntField(BaseField):
 
     def __init__(self, min_value=None, max_value=None, **kwargs):
         self.min_value, self.max_value = min_value, max_value
-        BaseField.__init__(self, **kwargs)
+        super(IntField, self).__init__(**kwargs)
     
     def _to_python(self, value):
         return int(value)
@@ -48,4 +49,10 @@ class EmbeddedDocumentField(BaseField):
     """An embedded document field. Only valid values are subclasses of 
     EmbeddedDocument. 
     """
-    pass
+
+    def __init__(self, document, **kwargs):
+        if not issubclass(document, EmbeddedDocument):
+            raise ValidationError('Invalid embedded document provided to an '
+                                  'EmbeddedDocumentField')
+        self.document = document
+        super(EmbeddedDocumentField, self).__init__(**kwargs)

tests/fields.py

@@ -17,6 +17,22 @@ class FieldTest(unittest.TestCase):
         self.assertEqual(person._data['age'], 30)
         self.assertEqual(person._data['userid'], 'test')
 
+    def test_required_values(self):
+        """Ensure that required field constraints are enforced.
+        """
+        class Person(Document):
+            name = StringField(object_id=True)
+            age = IntField(required=True)
+            userid = StringField()
+
+        self.assertRaises(ValidationError, Person, name="Test User")
+        self.assertRaises(ValidationError, Person, age=30)
+
+        person = Person(name="Test User", age=30, userid="testuser")
+        self.assertRaises(ValidationError, person.__setattr__, 'name', None)
+        self.assertRaises(ValidationError, person.__setattr__, 'age', None)
+        person.userid = None
+
     def test_string_validation(self):
         """Ensure that invalid values cannot be assigned to string fields.
         """