""" A collection of utility routines and classes used by the spatial backends. """ class SpatialOperator: """ 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