1 """

     2  This object provides quoting for GEOS geometries into PostgreSQL/PostGIS.

     3 """

     4 

     5 from psycopg2 import Binary

     6 from psycopg2.extensions import ISQLQuote

     7 

     8 class PostGISAdapter(object):

     9     def __init__(self, geom):

    10         "Initializes on the geometry."

    11         # Getting the WKB (in string form, to allow easy pickling of

    12         # the adaptor) and the SRID from the geometry.

    13         self.ewkb = str(geom.ewkb)

    14         self.srid = geom.srid

    15 

    16     def __conform__(self, proto):

    17         # Does the given protocol conform to what Psycopg2 expects?

    18         if proto == ISQLQuote:

    19             return self

    20         else:

    21             raise Exception('Error implementing psycopg2 protocol. Is psycopg2 installed?')

    22 

    23     def __eq__(self, other):

    24         return (self.ewkb == other.ewkb) and (self.srid == other.srid)

    25 

    26     def __str__(self):

    27         return self.getquoted()

    28 

    29     def getquoted(self):

    30         "Returns a properly quoted string for use in PostgreSQL/PostGIS."

    31         # Want to use WKB, so wrap with psycopg2 Binary() to quote properly.

    32         return 'ST_GeomFromEWKB(E%s)' % Binary(self.ewkb)

    33 

    34     def prepare_database_save(self, unused):

    35         return self