diff --git a/django/contrib/gis/db/models/proxy.py b/django/contrib/gis/db/models/proxy.py index 82158486b30..e569dd5c4fa 100644 --- a/django/contrib/gis/db/models/proxy.py +++ b/django/contrib/gis/db/models/proxy.py @@ -1,42 +1,44 @@ """ - 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