Restructured files to avoid circular imports

mongomap/fields.py

@@ -1,85 +1,20 @@
+from base import BaseField, ValidationError
+from document import EmbeddedDocument
+ 
 import re
 
 
 __all__ = ['StringField', 'IntField', 'ValidationError']
 
 
-class ValidationError(Exception):
-    pass
-
-
-class Field(object):
-    """A base class for fields in a MongoDB document. Instances of this class
-    may be added to subclasses of `Document` to define a document's schema.
-    """
-    
-    def __init__(self, name=None, default=None):
-        self.name = name
-        self.default = default
-
-    def __get__(self, instance, owner):
-        """Descriptor for retrieving a value from a field in a document. Do 
-        any necessary conversion between Python and MongoDB types.
-        """
-        if instance is None:
-            # Document class being used rather than a document object
-            return self
-
-        # Get value from document instance if available, if not use default
-        value = instance._data.get(self.name)
-        if value is not None:
-            value = self._to_python(value)
-        elif self.default is not None:
-            value = self.default
-            if callable(value):
-                value = value()
-        return value
-
-    def __set__(self, instance, value):
-        """Descriptor for assigning a value to a field in a document. Do any 
-        necessary conversion between Python and MongoDB types.
-        """
-        if value is not None:
-            try:
-                value = self._to_python(value)
-                self._validate(value)
-                value = self._to_mongo(value)
-            except ValueError:
-                raise ValidationError('Invalid value for field of type "' +
-                                      self.__class__.__name__ + '"')
-        instance._data[self.name] = value
-
-    def _to_python(self, value):
-        """Convert a MongoDB-compatible type to a Python type.
-        """
-        return unicode(value)
-
-    def _to_mongo(self, value):
-        """Convert a Python type to a MongoDB-compatible type.
-        """
-        return self._to_python(value)
-
-    def _validate(self, value):
-        """Perform validation on a value.
-        """
-        return value
-
-
-class NestedDocumentField(Field):
-    """A nested document field. Only valid values are subclasses of 
-    NestedDocument. 
-    """
-    pass
-
-
-class StringField(Field):
+class StringField(BaseField):
     """A unicode string field.
     """
     
     def __init__(self, regex=None, max_length=None, **kwargs):
         self.regex = re.compile(regex) if regex else None
         self.max_length = max_length
-        Field.__init__(self, **kwargs)
+        BaseField.__init__(self, **kwargs)
 
     def _validate(self, value):
         if self.max_length is not None and len(value) > self.max_length:
@@ -90,13 +25,13 @@ class StringField(Field):
             raise ValidationError(message)
 
 
-class IntField(Field):
+class IntField(BaseField):
     """An integer field.
     """
 
     def __init__(self, min_value=None, max_value=None, **kwargs):
         self.min_value, self.max_value = min_value, max_value
-        Field.__init__(self, **kwargs)
+        BaseField.__init__(self, **kwargs)
     
     def _to_python(self, value):
         return int(value)
@@ -107,3 +42,10 @@ class IntField(Field):
 
         if self.max_value is not None and value > self.max_value:
             raise ValidationError('Integer value is too large')
+
+
+class EmbeddedDocumentField(BaseField):
+    """An embedded document field. Only valid values are subclasses of 
+    EmbeddedDocument. 
+    """
+    pass