Introduce dynamic scope_path regexps Instead of relying on scope_path's being "one slash deep", we should instead allow for either: 1. scope_paths that have a pre-defined depth 2. scope_paths that can be arbitrarily deep We achieve 1 by setting an entities scope_logic to another logic module. We then recursively call getScopeDepth until we get to the topmost entity (that is, an unscoped entity). A little different is the solution to 2, since some entities can have an arbitrarily deep scope (such as Documents), we need to have some way of signaling this to getScopePattern. A clean solution is to return None, rather than a number. If None is returned, the SCOPE_PATH_ARG_PATTERN is returned as regexp instead, which will match an arbitrarily deeply nested scope. The solution for 2 requires that we return None somewhere in the scope_logic chain, the most straight forward method to do so is to override getScopeDepth anywhere such a scope is needed and make it return None. A more elegant solution however, is to set the scope_logic to that module in all entities that require it. Patch by: Sverre Rabbelier

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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)