Fixed #11353 -- `GeometryProxy` descriptor no longer chokes when accessed from a…

Fixed #11353 -- `GeometryProxy` descriptor no longer chokes when accessed from a class rather than an instance, thanks yml and Tobu; removed unnecessary imports from `types` and cleaned up whitespace.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@12584 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/gis/db/models/proxy.py

 """
- The GeometryProxy object, allows for lazy-geometries.  The proxy uses
- Python descriptors for instantiating and setting Geometry objects
- corresponding to geographic model fields.
+The GeometryProxy object, allows for lazy-geometries.  The proxy uses
+Python descriptors for instantiating and setting Geometry objects
+corresponding to geographic model fields.
 
- Thanks to Robert Coup for providing this functionality (see #4322).
+Thanks to Robert Coup for providing this functionality (see #4322).
 """
 
-from types import NoneType, StringType, UnicodeType
-
-class GeometryProxy(object): 
-    def __init__(self, klass, field): 
+class GeometryProxy(object):
+    def __init__(self, klass, field):
         """
-        Proxy initializes on the given Geometry class (not an instance) and 
+        Proxy initializes on the given Geometry class (not an instance) and
         the GeometryField.
         """
-        self._field = field 
+        self._field = field
         self._klass = klass
-     
-    def __get__(self, obj, type=None): 
+
+    def __get__(self, obj, type=None):
         """
         This accessor retrieves the geometry, initializing it using the geometry
-        class specified during initialization and the HEXEWKB value of the field.  
+        class specified during initialization and the HEXEWKB value of the field.
         Currently, only GEOS or OGR geometries are supported.
         """
+        if obj is None:
+            # Accessed on a class, not an instance
+            return self
+
         # Getting the value of the field.
-        geom_value = obj.__dict__[self._field.attname] 
-        
-        if isinstance(geom_value, self._klass): 
+        geom_value = obj.__dict__[self._field.attname]
+
+        if isinstance(geom_value, self._klass):
             geom = geom_value
         elif (geom_value is None) or (geom_value==''):
             geom = None
-        else: 
+        else:
             # Otherwise, a Geometry object is built using the field's contents,
             # and the model's corresponding attribute is set.
             geom = self._klass(geom_value)
-            setattr(obj, self._field.attname, geom) 
-        return geom 
-     
+            setattr(obj, self._field.attname, geom)
+        return geom
+
     def __set__(self, obj, value):
         """
         This accessor sets the proxied geometry with the geometry class
@@ -45,18 +47,18 @@ class GeometryProxy(object):
         """
         # The OGC Geometry type of the field.
         gtype = self._field.geom_type
-        
+
         # The geometry type must match that of the field -- unless the
         # general GeometryField is used.
         if isinstance(value, self._klass) and (str(value.geom_type).upper() == gtype or gtype == 'GEOMETRY'):
             # Assigning the SRID to the geometry.
             if value.srid is None: value.srid = self._field.srid
-        elif isinstance(value, (NoneType, StringType, UnicodeType)):
-            # Set with None, WKT, or HEX
+        elif value is None or isinstance(value, (basestring, buffer)):
+            # Set with None, WKT, HEX, or WKB
             pass
         else:
             raise TypeError('cannot set %s GeometryProxy with value of type: %s' % (obj.__class__.__name__, type(value)))
 
         # Setting the objects dictionary with the value, and returning.
-        obj.__dict__[self._field.attname] = value 
-        return value 
+        obj.__dict__[self._field.attname] = value
+        return value