28 lines
1.1 KiB
Python
28 lines
1.1 KiB
Python
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def add_postgis_srs(srs):
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"""
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This function takes a GDAL SpatialReference system and adds its
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information to the PostGIS `spatial_ref_sys` table -- enabling
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spatial transformations with PostGIS. This is handy for adding
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spatial reference systems not included by default with PostGIS.
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For example, the following adds the so-called "Google Maps Mercator
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Projection" (available in GDAL 1.5):
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>>> add_postgis_srs(SpatialReference(900913))
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Note: By default, the `auth_name` is set to 'EPSG' -- this should
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probably be changed.
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"""
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from django.contrib.gis.models import SpatialRefSys
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from django.contrib.gis.gdal import SpatialReference
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if not isinstance(srs, SpatialReference):
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srs = SpatialReference(srs)
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if srs.srid is None:
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raise Exception('Spatial reference requires an SRID to be compatible with PostGIS.')
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# Creating the spatial_ref_sys model.
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sr, created = SpatialRefSys.objects.get_or_create(
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srid=srs.srid, auth_name='EPSG', auth_srid=srs.srid,
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srtext=srs.wkt, proj4text=srs.proj4)
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