app/django/contrib/gis/utils/srs.py
author Madhusudan C.S. <madhusudancs@gmail.com>
Mon, 08 Jun 2009 08:42:13 +0200
changeset 2406 6f966e1a80bc
parent 323 ff1a9aa48cfd
permissions -rw-r--r--
Changed the property that holds the minimum age required for Students to participate in a GHOP based program. Added a new property student_min_age_as_of to hold the DateTime from when the minimum age should be reached. Changed student_min_age property to now store the student minimum age as an integer. This all feel more user friendly then letting the program admin calculate the required DateTime. Storing the two properties is then still needed in this case since information might be lost otherwise when the program admin brings up the edit view. Reviewed by: Lennard de Rijk

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)