Commit a2dd618e authored by Marc Tamlyn's avatar Marc Tamlyn
Browse files

Fixed #22648 -- Transform.output_type should respect overridden custom_lookup and custom_transform. 

Previously, class lookups from the output_type would be used, but any
changes to custom_lookup or custom_transform would be ignored.
parent 11932e97

django/db/models/lookups.py

+4 −2
Original line number Diff line number Diff line
@@ -22,18 +22,20 @@ class RegisterLookupMixin(object): 
        except AttributeError:

            # This class didn't have any class_lookups

            pass

        if hasattr(self, 'output_type'):

            return self.output_type.get_lookup(lookup_name)

        return None



    def get_lookup(self, lookup_name):

        found = self._get_lookup(lookup_name)

        if found is None and hasattr(self, 'output_type'):

            return self.output_type.get_lookup(lookup_name)

        if found is not None and not issubclass(found, Lookup):

            return None

        return found



    def get_transform(self, lookup_name):

        found = self._get_lookup(lookup_name)

        if found is None and hasattr(self, 'output_type'):

            return self.output_type.get_transform(lookup_name)

        if found is not None and not issubclass(found, Transform):

            return None

        return found

tests/custom_lookups/tests.py

+60 −0
Original line number Diff line number Diff line
@@ -89,6 +89,47 @@ class YearLte(models.lookups.LessThanOrEqual): 
YearTransform.register_lookup(YearLte)





class SQLFunc(models.Lookup):

    def __init__(self, name, *args, **kwargs):

        super(SQLFunc, self).__init__(*args, **kwargs)

        self.name = name



    def as_sql(self, qn, connection):

        return '%s()', [self.name]



    @property

    def output_type(self):

        return CustomField()





class SQLFuncFactory(object):



    def __init__(self, name):

        self.name = name



    def __call__(self, *args, **kwargs):

        return SQLFunc(self.name, *args, **kwargs)





class CustomField(models.Field):



    def get_lookup(self, lookup_name):

        if lookup_name.startswith('lookupfunc_'):

            key, name = lookup_name.split('_', 1)

            return SQLFuncFactory(name)

        return super(CustomField, self).get_lookup(lookup_name)



    def get_transform(self, lookup_name):

        if lookup_name.startswith('transformfunc_'):

            key, name = lookup_name.split('_', 1)

            return SQLFuncFactory(name)

        return super(CustomField, self).get_transform(lookup_name)





class CustomModel(models.Model):

    field = CustomField()





# We will register this class temporarily in the test method.
@@ -341,3 +382,22 @@ class LookupTransformCallOrderTests(TestCase): 


        finally:

            models.DateField._unregister_lookup(TrackCallsYearTransform)





class CustomisedMethodsTests(TestCase):



    def test_overridden_get_lookup(self):

        q = CustomModel.objects.filter(field__lookupfunc_monkeys=3)

        self.assertIn('monkeys()', str(q.query))



    def test_overridden_get_transform(self):

        q = CustomModel.objects.filter(field__transformfunc_banana=3)

        self.assertIn('banana()', str(q.query))



    def test_overridden_get_lookup_chain(self):

        q = CustomModel.objects.filter(field__transformfunc_banana__lookupfunc_elephants=3)

        self.assertIn('elephants()', str(q.query))



    def test_overridden_get_transform_chain(self):

        q = CustomModel.objects.filter(field__transformfunc_banana__transformfunc_pear=3)

        self.assertIn('pear()', str(q.query))