Added ListField type with unit tests

mongomap/base.py

@@ -44,7 +44,7 @@ class BaseField(object):
             try:
                 value = self._to_python(value)
                 self._validate(value)
-            except (ValueError, AttributeError):
+            except (ValueError, AttributeError, AssertionError):
                 raise ValidationError('Invalid value for field of type "' +
                                       self.__class__.__name__ + '"')
         elif self.required:

mongomap/fields.py

@@ -5,7 +5,7 @@ import re
 import pymongo
 
 
-__all__ = ['StringField', 'IntField', 'EmbeddedDocumentField', 
+__all__ = ['StringField', 'IntField', 'EmbeddedDocumentField', 'ListField',
            'ObjectIdField', 'ValidationError']
 
 
@@ -18,7 +18,13 @@ class StringField(BaseField):
         self.max_length = max_length
         super(StringField, self).__init__(**kwargs)
     
+    def _to_python(self, value):
+        assert(isinstance(value, (str, unicode)))
+        return unicode(value)
+
     def _validate(self, value):
+        assert(isinstance(value, (str, unicode)))
+
         if self.max_length is not None and len(value) > self.max_length:
             raise ValidationError('String value is too long')
 
@@ -36,9 +42,12 @@ class IntField(BaseField):
         super(IntField, self).__init__(**kwargs)
     
     def _to_python(self, value):
+        assert(isinstance(value, int))
         return int(value)
 
     def _validate(self, value):
+        assert(isinstance(value, int))
+
         if self.min_value is not None and value < self.min_value:
             raise ValidationError('Integer value is too small')
 
@@ -74,3 +83,41 @@ class EmbeddedDocumentField(BaseField):
         if not isinstance(value, self.document):
             raise ValidationError('Invalid embedded document instance '
                                   'provided to an EmbeddedDocumentField')
+
+
+class ListField(BaseField):
+    """A list field that wraps a standard field, allowing multiple instances
+    of the field to be used as a list in the database.
+    """
+
+    def __init__(self, field, **kwargs):
+        if not isinstance(field, BaseField):
+            raise ValidationError('Argument to ListField constructor must be '
+                                  'a valid field')
+        self.field = field
+        super(ListField, self).__init__(**kwargs)
+
+    def _to_python(self, value):
+        assert(isinstance(value, (list, tuple)))
+        return list(value)
+
+    def _to_mongo(self, value):
+        return [self.field._to_mongo(item) for item in value]
+
+    def _validate(self, value):
+        """Make sure that a list of valid fields is being used.
+        """
+#        print
+#        print value
+#        print type(value)
+#        print isinstance(value, list)
+#        print
+        if not isinstance(value, (list, tuple)):
+            raise ValidationError('Only lists and tuples may be used in a '
+                                  'list field')
+
+        try:
+            [self.field._validate(item) for item in value]
+        except:
+            raise ValidationError('All items in a list field must be of the '
+                                  'specified type')

tests/document.py

@@ -111,6 +111,29 @@ class DocumentTest(unittest.TestCase):
         person_obj = collection.find_one({'name': 'Test User'})
         self.assertEqual(str(person_obj['_id']), '497ce96f395f2f052a494fd4')
 
+    def test_save_list(self):
+        """Ensure that a list field may be properly saved.
+        """
+        class Comment(EmbeddedDocument):
+            content = StringField()
+
+        class BlogPost(Document):
+            content = StringField()
+            comments = ListField(EmbeddedDocumentField(Comment))
+            tags = ListField(StringField())
+
+        post = BlogPost(content='Went for a walk today...')
+        post.tags = tags = ['fun', 'leisure']
+        comments = [Comment(content='Good for you'), Comment(content='Yay.')]
+        post.comments = comments
+        post.save()
+
+        collection = self.db[BlogPost._meta['collection']]
+        post_obj = collection.find_one()
+        self.assertEqual(post_obj['tags'], tags)
+        for comment_obj, comment in zip(post_obj['comments'], comments):
+            self.assertEqual(comment_obj['content'], comment['content'])
+
     def test_save_embedded_document(self):
         """Ensure that a document with an embedded document field may be 
         saved in the database.

tests/fields.py

@@ -56,6 +56,8 @@ class FieldTest(unittest.TestCase):
             userid = StringField(r'[0-9a-z_]+$')
 
         person = Person()
+        self.assertRaises(ValidationError, person.__setattr__, 'name', 34)
+
         # Test regex validation on userid
         self.assertRaises(ValidationError, person.__setattr__, 'userid',
                           'test.User')
@@ -80,6 +82,29 @@ class FieldTest(unittest.TestCase):
         self.assertRaises(ValidationError, person.__setattr__, 'age', 120)
         self.assertRaises(ValidationError, person.__setattr__, 'age', 'ten')
 
+    def test_list_validation(self):
+        """Ensure that a list field only accepts lists with valid elements.
+        """
+        class Comment(EmbeddedDocument):
+            content = StringField()
+
+        class BlogPost(Document):
+            content = StringField()
+            comments = ListField(EmbeddedDocumentField(Comment))
+            tags = ListField(StringField())
+
+        post = BlogPost(content='Went for a walk today...')
+        self.assertRaises(ValidationError, post.__setattr__, 'tags', 'fun')
+        self.assertRaises(ValidationError, post.__setattr__, 'tags', [1, 2])
+        post.tags = ['fun', 'leisure']
+        post.tags = ('fun', 'leisure')
+
+        comments = [Comment(content='Good for you'), Comment(content='Yay.')]
+        self.assertRaises(ValidationError, post.__setattr__, 'comments', ['a'])
+        self.assertRaises(ValidationError, post.__setattr__, 'comments', 'Yay')
+        self.assertRaises(ValidationError, post.__setattr__, 'comments', 'Yay')
+        post.comments = comments
+
     def test_embedded_document_validation(self):
         """Ensure that invalid embedded documents cannot be assigned to
         embedded document fields.