Fixed #10660 -- GeometryField no longer requires srid/null keywords, and now respects required; coordinate transformations now done inside gis.forms.GeometryField -- benefit being that OSMGeoAdmin no longer requires 900913 entry in spatial_ref_sys thus enabling it to work with MySQL/Oracle spatial backends; added tests for geographic forms.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@10634 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/gis/forms/fields.py

@@ -1,12 +1,15 @@
 from django import forms
-from django.contrib.gis.db.backend import SpatialBackend
 from django.utils.translation import ugettext_lazy as _
 
+# While this couples the geographic forms to the GEOS library,
+# it decouples from database (by not importing SpatialBackend).
+from django.contrib.gis.geos import GEOSGeometry
+
 class GeometryField(forms.Field):
     """
     This is the basic form field for a Geometry.  Any textual input that is
-    accepted by SpatialBackend.Geometry is accepted by this form.  By default, 
-    this is GEOSGeometry, which accepts WKT, HEXEWKB, WKB, and GeoJSON.
+    accepted by GEOSGeometry is accepted by this form.  By default,
+    this includes WKT, HEXEWKB, WKB (in a buffer), and GeoJSON.
     """
     widget = forms.Textarea
 
@@ -14,12 +17,16 @@ class GeometryField(forms.Field):
         'no_geom' : _(u'No geometry value provided.'),
         'invalid_geom' : _(u'Invalid geometry value.'),
         'invalid_geom_type' : _(u'Invalid geometry type.'),
-    }
+        'transform_error' : _(u'An error occurred when transforming the geometry'
+                              'to the SRID of the geometry form field.'),
+        }
 
     def __init__(self, **kwargs):
-        self.null = kwargs.pop('null')
-        self.geom_type = kwargs.pop('geom_type')
-        self.srid = kwargs.pop('srid')
+        # Pop out attributes from the database field, or use sensible
+        # defaults (e.g., allow None).
+        self.srid = kwargs.pop('srid', None)
+        self.geom_type = kwargs.pop('geom_type', 'GEOMETRY')
+        self.null = kwargs.pop('null', True)
         super(GeometryField, self).__init__(**kwargs)
 
     def clean(self, value):
@@ -29,21 +36,32 @@ class GeometryField(forms.Field):
         the value cannot be instantiated as a Geometry.
         """
         if not value:
-            if self.null:
-                # The geometry column allows NULL, return None.
+            if self.null and not self.required:
+                # The geometry column allows NULL and is not required.
                 return None
             else:
                 raise forms.ValidationError(self.error_messages['no_geom'])
-     
+
+        # Trying to create a Geometry object from the form value.
         try:
-            # Trying to create a Geometry object from the form value.
-            geom = SpatialBackend.Geometry(value)
+            geom = GEOSGeometry(value)
         except:
             raise forms.ValidationError(self.error_messages['invalid_geom'])
-  
+
         # Ensuring that the geometry is of the correct type (indicated
         # using the OGC string label).
         if str(geom.geom_type).upper() != self.geom_type and not self.geom_type == 'GEOMETRY':
             raise forms.ValidationError(self.error_messages['invalid_geom_type'])
 
+        # Transforming the geometry if the SRID was set.
+        if self.srid:
+            if not geom.srid:
+                # Should match that of the field if not given.
+                geom.srid = self.srid
+            elif self.srid != -1 and self.srid != geom.srid:
+                try:
+                    geom.transform(self.srid)
+                except:
+                    raise forms.ValidationError(self.error_messages['transform_error'])
+
         return geom