django1/django/contrib/gis/db/backends/utils.py

28 lines
792 B
Python

"""
A collection of utility routines and classes used by the spatial
backends.
"""
class SpatialOperator(object):
"""
Class encapsulating the behavior specific to a GIS operation (used by lookups).
"""
sql_template = None
def __init__(self, op=None, func=None):
self.op = op
self.func = func
@property
def default_template(self):
if self.func:
return '%(func)s(%(lhs)s, %(rhs)s)'
else:
return '%(lhs)s %(op)s %(rhs)s'
def as_sql(self, connection, lookup, template_params, sql_params):
sql_template = self.sql_template or lookup.sql_template or self.default_template
template_params.update({'op': self.op, 'func': self.func})
return sql_template % template_params, sql_params