--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/app/django/contrib/gis/utils/srs.py Tue Oct 14 16:00:59 2008 +0000
@@ -0,0 +1,27 @@
+def add_postgis_srs(srs):
+ """
+ This function takes a GDAL SpatialReference system and adds its
+ information to the PostGIS `spatial_ref_sys` table -- enabling
+ spatial transformations with PostGIS. This is handy for adding
+ spatial reference systems not included by default with PostGIS.
+ For example, the following adds the so-called "Google Maps Mercator
+ Projection" (available in GDAL 1.5):
+
+ >>> add_postgis_srs(SpatialReference(900913))
+
+ Note: By default, the `auth_name` is set to 'EPSG' -- this should
+ probably be changed.
+ """
+ from django.contrib.gis.models import SpatialRefSys
+ from django.contrib.gis.gdal import SpatialReference
+
+ if not isinstance(srs, SpatialReference):
+ srs = SpatialReference(srs)
+
+ if srs.srid is None:
+ raise Exception('Spatial reference requires an SRID to be compatible with PostGIS.')
+
+ # Creating the spatial_ref_sys model.
+ sr, created = SpatialRefSys.objects.get_or_create(
+ srid=srs.srid, auth_name='EPSG', auth_srid=srs.srid,
+ srtext=srs.wkt, proj4text=srs.proj4)