Ticket #5433: remove_gdal_dep.patch

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

@@ -1 @@
-# GEOS Routines
 from warnings import warn
+
+# GEOS is a requirement
 from django.contrib.gis.geos import GEOSGeometry
-from django.contrib.gis.gdal import OGRGeometry, SpatialReference
 
+# GDAL is a lot more complicated to install, and isn't necessary for many
+# operations.
+try:
+    from django.contrib.gis.gdal import OGRGeometry, SpatialReference
+    HAS_GDAL = True
+except ImportError, e:
+    HAS_GDAL = False
+
 # Until model subclassing is a possibility, a mixin class is used to add
 # the necessary functions that may be contributed for geographic objects.
 class GeoMixin:
@@ -17 +25 @@
 
     def _get_GEOM_ogr(self, field, srid):
         "Returns an OGR Python object for the geometry."
-        return OGRGeometry(getattr(self, field.attname).wkt,
-                           SpatialReference('EPSG:%d' % srid))
+        if HAS_GDAL:
+            return OGRGeometry(getattr(self, field.attname).wkt,
+                               SpatialReference('EPSG:%d' % srid))
+        else:
+            raise Exception, "GDAL is not installed!"
 
     def _get_GEOM_srid(self, srid):
         "Returns the spatial reference identifier (SRID) of the geometry."
@@ -27 +38 @@
 
     def _get_GEOM_srs(self, srid):
         "Returns ane OGR Spatial Reference object of the geometry."
-        return SpatialReference('EPSG:%d' % srid)
+        if HAS_GDAL:
+            return SpatialReference('EPSG:%d' % srid)
+        else:
+            raise Exception, "GDAL is not installed!"
 
     def _get_GEOM_wkt(self, field):
         "Returns the WKT of the geometry."