Fixed #25448 -- Eased GISLookup subclassing with custom lookups

When someone needs to build a custom backend-specific GIS lookup, it
is much easier done if getting the spatial operator class happens in
a dedicated method (no need to rewrite the entire as_sql() method).
This commit is contained in:
Claude Paroz 2015-09-23 09:25:08 +02:00
parent 135a9e4fd9
commit c9a02bc8f5
1 changed files with 8 additions and 2 deletions

View File

@ -87,14 +87,20 @@ class GISLookup(Lookup):
rhs = connection.ops.get_geom_placeholder(self.lhs.output_field, geom, compiler)
return rhs, rhs_params
def get_rhs_op(self, connection, rhs):
# Unlike BuiltinLookup, the GIS get_rhs_op() implementation should return
# an object (SpatialOperator) with an as_sql() method to allow for more
# complex computations (where the lhs part can be mixed in).
return connection.ops.gis_operators[self.lookup_name]
def as_sql(self, compiler, connection):
lhs_sql, sql_params = self.process_lhs(compiler, connection)
rhs_sql, rhs_params = self.process_rhs(compiler, connection)
sql_params.extend(rhs_params)
template_params = {'lhs': lhs_sql, 'rhs': rhs_sql}
backend_op = connection.ops.gis_operators[self.lookup_name]
return backend_op.as_sql(connection, self, template_params, sql_params)
rhs_op = self.get_rhs_op(connection, rhs_sql)
return rhs_op.as_sql(connection, self, template_params, sql_params)
# ------------------