37 lines
1.2 KiB
Python
37 lines
1.2 KiB
Python
"""
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This object provides quoting for GEOS geometries into PostgreSQL/PostGIS.
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"""
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from django.contrib.gis.db.backend.postgis.query import GEOM_FROM_EWKB
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from psycopg2 import Binary
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from psycopg2.extensions import ISQLQuote
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class PostGISAdaptor(object):
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def __init__(self, geom):
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"Initializes on the geometry."
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# Getting the WKB (in string form, to allow easy pickling of
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# the adaptor) and the SRID from the geometry.
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self.ewkb = str(geom.ewkb)
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self.srid = geom.srid
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def __conform__(self, proto):
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# Does the given protocol conform to what Psycopg2 expects?
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if proto == ISQLQuote:
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return self
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else:
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raise Exception('Error implementing psycopg2 protocol. Is psycopg2 installed?')
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def __eq__(self, other):
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return (self.wkb == other.wkb) and (self.srid == other.srid)
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def __str__(self):
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return self.getquoted()
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def getquoted(self):
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"Returns a properly quoted string for use in PostgreSQL/PostGIS."
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# Want to use WKB, so wrap with psycopg2 Binary() to quote properly.
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return "%s(E%s)" % (GEOM_FROM_EWKB, Binary(self.ewkb))
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def prepare_database_save(self, unused):
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return self
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