| """ |
| 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 |
