Fixed sort query aliased hybrid property handling

sqlalchemy_utils/functions/__init__.py

@@ -7,7 +7,7 @@ from sqlalchemy.orm.properties import ColumnProperty
 from sqlalchemy.orm.query import Query
 from sqlalchemy.schema import MetaData, Table, ForeignKeyConstraint
 from .batch_fetch import batch_fetch, with_backrefs, CompositePath
-from .sort_query import sort_query
+from .sort_query import sort_query, QuerySorterException
 
 
 __all__ = (
@@ -15,6 +15,7 @@ __all__ = (
     sort_query,
     with_backrefs,
     CompositePath,
+    QuerySorterException
 )
 
 

sqlalchemy_utils/functions/sort_query.py

@@ -20,15 +20,6 @@ def sort_expression(expr, attr_name):
         return getattr(expr, attr_name)
 
 
-def get_entity(expr):
-    if isinstance(expr, AliasedInsp):
-        return expr.mapper.class_
-    elif isinstance(expr, Mapper):
-        return expr.class_
-    else:
-        return expr
-
-
 def matches_entity(alias, entity):
     if not alias:
         return True
@@ -40,11 +31,16 @@ def matches_entity(alias, entity):
     return name == alias
 
 
+class QuerySorterException(Exception):
+    pass
+
+
 class QuerySorter(object):
-    def __init__(self, separator='-'):
+    def __init__(self, silent=True, separator='-'):
         self.entities = []
         self.labels = []
         self.separator = separator
+        self.silent = silent
 
     def inspect_labels_and_entities(self):
         for entity in self.query._entities:
@@ -69,37 +65,41 @@ class QuerySorter(object):
             return self.query
 
         sort = self.parse_sort_arg(sort)
+        expr = None
         if sort['attr'] in self.labels:
-            return self.query.order_by(sort['func'](sort['attr']))
+            expr = sort['attr']
+        else:
+            for entity in self.entities:
+                if not matches_entity(sort['entity'], entity):
+                    continue
 
-        for entity in self.entities:
-            if not matches_entity(sort['entity'], entity):
-                continue
-
-            return self.assign_entity_attr_order_by(entity, sort)
+                expr = self.order_by_attr(entity, sort['attr'])
 
+        if expr is not None:
+            return self.query.order_by(
+                sort['func'](expr)
+            )
+        if not self.silent:
+            raise QuerySorterException(
+                "Could not sort query with expression '%s'" % sort['attr']
+            )
         return self.query
 
-    def assign_entity_attr_order_by(self, entity, sort):
+    def order_by_attr(self, entity, attr):
         properties = attrs(entity)
-        if sort['attr'] in properties:
-            property_ = properties[sort['attr']]
+        if attr in properties:
+            property_ = properties[attr]
             if isinstance(property_, ColumnProperty):
                 if isinstance(property_.columns[0], Label):
                     expr = property_.columns[0].name
                 else:
                     expr = sort_expression(entity, property_.key)
-            return self.query.order_by(sort['func'](
-                expr
-            ))
+            return expr
 
-        # Check hybrid properties.
-        entity = get_entity(entity)
-        if hasattr(entity, sort['attr']):
-            return self.query.order_by(
-                sort['func'](getattr(entity, sort['attr']))
-            )
-        return self.query
+        if isinstance(entity, AliasedInsp):
+            entity = entity.entity
+        if hasattr(entity, attr):
+            return getattr(entity, attr)
 
     def parse_sort_arg(self, arg):
         if arg[0] == self.separator:
@@ -123,7 +123,7 @@ class QuerySorter(object):
         return self.query
 
 
-def sort_query(query, *args):
+def sort_query(query, *args, **kwargs):
     """
     Applies an sql ORDER BY for given query. This function can be easily used
     with user-defined sorting.
@@ -192,4 +192,4 @@ def sort_query(query, *args):
                    is passed
     """
 
-    return QuerySorter()(query, *args)
+    return QuerySorter(**kwargs)(query, *args)

tests/test_sort_query.py

@@ -1,5 +1,7 @@
+from pytest import raises
 import sqlalchemy as sa
 from sqlalchemy_utils import sort_query
+from sqlalchemy_utils.functions import QuerySorterException
 from tests import TestCase
 
 
@@ -22,6 +24,11 @@ class TestSortQuery(TestCase):
         sorted_query = sort_query(query, '-unknown')
         assert query == sorted_query
 
+    def test_non_silent_mode(self):
+        query = self.session.query(self.Article)
+        with raises(QuerySorterException):
+            sort_query(query, '-unknown', silent=False)
+
     def test_calculated_value_ascending(self):
         query = self.session.query(
             self.Category, sa.func.count(self.Article.id).label('articles')
@@ -116,10 +123,10 @@ class TestSortQuery(TestCase):
         query = sort_query(query, '-category-articles_count')
         assert 'ORDER BY (SELECT count(article.id) AS count_1' in str(query)
 
-    def test_aliased_relation_hybrid_property(self):
+    def test_aliased_hybrid_property(self):
         alias = sa.orm.aliased(
             self.Category,
-            name='category'
+            name='categories'
         )
         query = (
             self.session.query(self.Article)
@@ -128,5 +135,5 @@ class TestSortQuery(TestCase):
                 sa.orm.contains_eager(self.Article.category, alias=alias)
             )
         )
-        query = sort_query(query, '-category-articles_count')
+        query = sort_query(query, '-categories-articles_count')
         assert 'ORDER BY (SELECT count(article.id) AS count_1' in str(query)