app/django/contrib/gis/utils/srs.py
author Sverre Rabbelier <srabbelier@gmail.com>
Sun, 16 Nov 2008 23:02:31 +0000
changeset 493 6976c4d8d0ac
parent 323 ff1a9aa48cfd
permissions -rw-r--r--
Refactor the sidebar to use Django templates With this change the html for the sidebar is no longer generated by Melange, instead it's delegated to Django (which is what it does best anyway). The downside is that it is no longer possible to have arbitrary deeply nested menu's.

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)