django1/django/contrib/gis/db/backend/postgis/adaptor.py

34 lines
1.2 KiB
Python

"""
This object provides quoting for GEOS geometries into PostgreSQL/PostGIS.
"""
from django.contrib.gis.db.backend.postgis.query import GEOM_FROM_WKB
from psycopg2 import Binary
from psycopg2.extensions import ISQLQuote
class PostGISAdaptor(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.wkb = str(geom.wkb)
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.wkb == other.wkb) 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 "%s(%s, %s)" % (GEOM_FROM_WKB, Binary(self.wkb), self.srid or -1)