[1.7.x] Fixed #22819 -- Renamed output_type -> output_field in query expression API.

Thanks jorgecarleitao for the suggestion.

Backport of 95cc0e15b4 from master

django/contrib/gis/db/models/lookups.py

@@ -16,13 +16,13 @@ class GISLookup(Lookup):
             if not geo_fld:
                 raise ValueError('No geographic field found in expression.')
             self.rhs.srid = geo_fld.srid
-        db_type = self.lhs.output_type.db_type(connection=connection)
-        params = self.lhs.output_type.get_db_prep_lookup(
+        db_type = self.lhs.output_field.db_type(connection=connection)
+        params = self.lhs.output_field.get_db_prep_lookup(
             self.lookup_name, self.rhs, connection=connection)
         lhs_sql, lhs_params = self.process_lhs(qn, connection)
         # lhs_params not currently supported.
         assert not lhs_params
         data = (lhs_sql, db_type)
         spatial_sql, spatial_params = connection.ops.spatial_lookup_sql(
-            data, self.lookup_name, self.rhs, self.lhs.output_type, qn)
+            data, self.lookup_name, self.rhs, self.lhs.output_field, qn)
         return spatial_sql, spatial_params + params

django/db/models/lookups.py

@@ -26,16 +26,16 @@ class RegisterLookupMixin(object):
 
     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 None and hasattr(self, 'output_field'):
+            return self.output_field.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 None and hasattr(self, 'output_field'):
+            return self.output_field.get_transform(lookup_name)
         if found is not None and not issubclass(found, Transform):
             return None
         return found
@@ -64,8 +64,8 @@ class Transform(RegisterLookupMixin):
         raise NotImplementedError
 
     @cached_property
-    def output_type(self):
-        return self.lhs.output_type
+    def output_field(self):
+        return self.lhs.output_field
 
     def relabeled_clone(self, relabels):
         return self.__class__(self.lhs.relabeled_clone(relabels))
@@ -82,11 +82,11 @@ class Lookup(RegisterLookupMixin):
         self.rhs = self.get_prep_lookup()
 
     def get_prep_lookup(self):
-        return self.lhs.output_type.get_prep_lookup(self.lookup_name, self.rhs)
+        return self.lhs.output_field.get_prep_lookup(self.lookup_name, self.rhs)
 
     def get_db_prep_lookup(self, value, connection):
         return (
-            '%s', self.lhs.output_type.get_db_prep_lookup(
+            '%s', self.lhs.output_field.get_db_prep_lookup(
                 self.lookup_name, value, connection, prepared=True))
 
     def process_lhs(self, qn, connection, lhs=None):
@@ -138,8 +138,8 @@ class BuiltinLookup(Lookup):
     def process_lhs(self, qn, connection, lhs=None):
         lhs_sql, params = super(BuiltinLookup, self).process_lhs(
             qn, connection, lhs)
-        field_internal_type = self.lhs.output_type.get_internal_type()
-        db_type = self.lhs.output_type.db_type(connection=connection)
+        field_internal_type = self.lhs.output_field.get_internal_type()
+        db_type = self.lhs.output_field.db_type(connection=connection)
         lhs_sql = connection.ops.field_cast_sql(
             db_type, field_internal_type) % lhs_sql
         lhs_sql = connection.ops.lookup_cast(self.lookup_name) % lhs_sql
@@ -203,7 +203,7 @@ class In(BuiltinLookup):
     lookup_name = 'in'
 
     def get_db_prep_lookup(self, value, connection):
-        params = self.lhs.output_type.get_db_prep_lookup(
+        params = self.lhs.output_field.get_db_prep_lookup(
             self.lookup_name, value, connection, prepared=True)
         if not params:
             # TODO: check why this leads to circular import
@@ -299,7 +299,7 @@ class DateLookup(BuiltinLookup):
     def process_lhs(self, qn, connection, lhs=None):
         from django.db.models import DateTimeField
         lhs, params = super(DateLookup, self).process_lhs(qn, connection, lhs)
-        if isinstance(self.lhs.output_type, DateTimeField):
+        if isinstance(self.lhs.output_field, DateTimeField):
             tzname = timezone.get_current_timezone_name() if settings.USE_TZ else None
             sql, tz_params = connection.ops.datetime_extract_sql(self.extract_type, lhs, tzname)
             return connection.ops.lookup_cast(self.lookup_name) % sql, tz_params

django/db/models/sql/aggregates.py

@@ -103,7 +103,7 @@ class Aggregate(RegisterLookupMixin):
         return []
 
     @property
-    def output_type(self):
+    def output_field(self):
         return self.field
 
 

django/db/models/sql/datastructures.py

@@ -12,7 +12,7 @@ class Col(object):
         return "%s.%s" % (qn(self.alias), qn(self.target.column)), []
 
     @property
-    def output_type(self):
+    def output_field(self):
         return self.source
 
     def relabeled_clone(self, relabels):
@@ -22,10 +22,10 @@ class Col(object):
         return [(self.alias, self.target.column)]
 
     def get_lookup(self, name):
-        return self.output_type.get_lookup(name)
+        return self.output_field.get_lookup(name)
 
     def get_transform(self, name):
-        return self.output_type.get_transform(name)
+        return self.output_field.get_transform(name)
 
     def prepare(self):
         return self

django/db/models/sql/query.py

@@ -1102,7 +1102,7 @@ class Query(object):
                 raise FieldError(
                     "Unsupported lookup '%s' for %s or join on the field not "
                     "permitted." %
-                    (lookup, lhs.output_type.__class__.__name__))
+                    (lookup, lhs.output_field.__class__.__name__))
             lookups = lookups[1:]
 
     def build_filter(self, filter_expr, branch_negated=False, current_negated=False,
@@ -1190,7 +1190,7 @@ class Query(object):
                     raise FieldError(
                         "Join on field '%s' not permitted. Did you "
                         "misspell '%s' for the lookup type?" %
-                        (col.output_type.name, lookups[0]))
+                        (col.output_field.name, lookups[0]))
                 if len(lookups) > 1:
                     raise FieldError("Nested lookup '%s' not supported." %
                                      LOOKUP_SEP.join(lookups))

docs/ref/models/custom-lookups.txt

@@ -141,11 +141,11 @@ this case where there is no other lookup specified, Django interprets
 ``change__abs=27`` as ``change__abs__exact=27``.
 
 When looking for which lookups are allowable after the ``Transform`` has been
-applied, Django uses the ``output_type`` attribute. We didn't need to specify
+applied, Django uses the ``output_field`` attribute. We didn't need to specify
 this here as it didn't change, but supposing we were applying ``AbsoluteValue``
 to some field which represents a more complex type (for example a point
 relative to an origin, or a complex number) then we may have wanted to specify
-``output_type = FloatField``, which will ensure that further lookups like
+``output_field = FloatField``, which will ensure that further lookups like
 ``abs__lte`` behave as they would for a ``FloatField``.
 
 Writing an efficient abs__lt lookup
@@ -315,10 +315,10 @@ to this API.
     field. Generally speaking, you will not need to override ``get_lookup()``
     or ``get_transform()``, and can use ``register_lookup()`` instead.
 
-.. attribute:: output_type
+.. attribute:: output_field
 
-    The ``output_type`` attribute is used by the ``get_lookup()`` method to check for
-    lookups. The output_type should be a field.
+    The ``output_field`` attribute is used by the ``get_lookup()`` method to
+    check for lookups. The ``output_field`` should be a field.
 
 Note that this documentation lists only the public methods of the API.
 

tests/custom_lookups/tests.py

@@ -46,7 +46,7 @@ class YearTransform(models.Transform):
         return connection.ops.date_extract_sql('year', lhs_sql), params
 
     @property
-    def output_type(self):
+    def output_field(self):
         return models.IntegerField()
 
 
@@ -98,7 +98,7 @@ class SQLFunc(models.Lookup):
         return '%s()', [self.name]
 
     @property
-    def output_type(self):
+    def output_field(self):
         return CustomField()
 
 
@@ -342,7 +342,7 @@ class TrackCallsYearTransform(YearTransform):
         return connection.ops.date_extract_sql('year', lhs_sql), params
 
     @property
-    def output_type(self):
+    def output_field(self):
         return models.IntegerField()
 
     def get_lookup(self, lookup_name):