--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/app/django/contrib/gis/forms/fields.py	Tue Oct 14 16:00:59 2008 +0000
@@ -0,0 +1,48 @@
+from django import forms
+from django.contrib.gis.db.backend import SpatialBackend
+from django.utils.translation import ugettext_lazy as _
+
+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.
+    """
+    widget = forms.Textarea
+
+    default_error_messages = {
+        'no_geom' : _(u'No geometry value provided.'),
+        'invalid_geom' : _(u'Invalid geometry value.'),
+        'invalid_geom_type' : _(u'Invalid geometry type.'),
+    }
+
+    def __init__(self, **kwargs):
+        self.null = kwargs.pop('null')
+        self.geom_type = kwargs.pop('geom_type')
+        super(GeometryField, self).__init__(**kwargs)
+
+    def clean(self, value):
+        """
+        Validates that the input value can be converted to a Geometry
+        object (which is returned).  A ValidationError is raised if
+        the value cannot be instantiated as a Geometry.
+        """
+        if not value:
+            if self.null:
+                # The geometry column allows NULL, return None.
+                return None
+            else:
+                raise forms.ValidationError(self.error_messages['no_geom'])
+     
+        try:
+            # Trying to create a Geometry object from the form value.
+            geom = SpatialBackend.Geometry(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'])
+
+        return geom