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)