Merge pull request #234 from vToMy/master

Added support for backref tuple to auto_delete_orphans

sqlalchemy_utils/listeners.py

@@ -235,6 +235,8 @@ def auto_delete_orphans(attr):
             'The relationship argument given for auto_delete_orphans needs to '
             'have a backref relationship set.'
         )
+    if isinstance(backref, tuple):
+        backref = backref[0]
 
     @sa.event.listens_for(sa.orm.Session, 'after_flush')
     def delete_orphan_listener(session, ctx):
@@ -257,7 +259,7 @@ def auto_delete_orphans(attr):
             (
                 session.query(target_class)
                 .filter(
-                    ~getattr(target_class, attr.property.backref).any()
+                    ~getattr(target_class, backref).any()
                 )
                 .delete(synchronize_session=False)
             )

tests/test_auto_delete_orphans.py

@@ -1,5 +1,6 @@
 import pytest
 import sqlalchemy as sa
+from sqlalchemy.orm import backref
 
 from sqlalchemy_utils import auto_delete_orphans, ImproperlyConfigured
 
@@ -36,17 +37,18 @@ def Tag(Base):
     return Tag
 
 
-@pytest.fixture
-def Entry(Base, Tag, tagging_tbl):
+@pytest.fixture(params=['entries', backref('entries', lazy='select')],
+                ids=['backref_string', 'backref_with_keywords'])
+def Entry(Base, Tag, tagging_tbl, request):
     class Entry(Base):
         __tablename__ = 'entry'
 
         id = sa.Column(sa.Integer, primary_key=True)
 
         tags = sa.orm.relationship(
-            'Tag',
+            Tag,
             secondary=tagging_tbl,
-            backref='entries'
+            backref=request.param
         )
     auto_delete_orphans(Entry.tags)
     return Entry
@@ -60,7 +62,7 @@ def EntryWithoutTagsBackref(Base, Tag, tagging_tbl):
         id = sa.Column(sa.Integer, primary_key=True)
 
         tags = sa.orm.relationship(
-            'Tag',
+            Tag,
             secondary=tagging_tbl
         )
     return EntryWithoutTagsBackref