"""

 This module holds the base `SpatialBackend` object, which is

 instantiated by each spatial backend with the features it has.

"""

# TODO: Create a `Geometry` protocol and allow user to use

# different Geometry objects -- for now we just use GEOSGeometry.

from django.contrib.gis.geos import GEOSGeometry, GEOSException

class BaseSpatialBackend(object):

    Geometry = GEOSGeometry

    GeometryException = GEOSException

    def __init__(self, **kwargs):

        kwargs.setdefault('distance_functions', {})

        kwargs.setdefault('limited_where', {})

        for k, v in kwargs.iteritems(): setattr(self, k, v)

    def __getattr__(self, name):

        """

        All attributes of the spatial backend return False by default.

        """

        try:

            return self.__dict__[name]

        except KeyError:

            return False