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