From a30b42421da68ba599291cac0b83b798b0a85c93 Mon Sep 17 00:00:00 2001
From: Konsta Vesterinen <konsta.vesterinen@gmail.com>
Date: Fri, 12 Dec 2014 10:13:48 +0200
Subject: [PATCH] Add direction and uselist properties

---
 sqlalchemy_utils/path.py | 16 +++++++++++++++-
 tests/test_path.py       | 14 +++++++++++++-
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/sqlalchemy_utils/path.py b/sqlalchemy_utils/path.py
index 96f274b..aaa812e 100644
--- a/sqlalchemy_utils/path.py
+++ b/sqlalchemy_utils/path.py
@@ -1,5 +1,6 @@
 import sqlalchemy as sa
 from sqlalchemy.orm.attributes import InstrumentedAttribute
+from sqlalchemy.util.langhelpers import symbol
 from .utils import str_coercible
 
 
@@ -105,9 +106,22 @@ class AttrPath(object):
             if el is element:
                 return index
 
+    @property
+    def direction(self):
+        symbols = [part.property.direction for part in self.parts]
+        if symbol('MANYTOMANY') in symbols:
+            return symbol('MANYTOMANY')
+        elif symbol('MANYTOONE') in symbols and symbol('ONETOMANY') in symbols:
+            return symbol('MANYTOMANY')
+        return symbols[0]
+
+    @property
+    def uselist(self):
+        return any(part.property.uselist for part in self.parts)
+
     def __getitem__(self, slice):
         result = self.parts[slice]
-        if isinstance(result, list):
+        if isinstance(result, list) and result:
             if result[0] is self.parts[0]:
                 class_ = self.class_
             else:
diff --git a/tests/test_path.py b/tests/test_path.py
index bc77e77..3246fa1 100644
--- a/tests/test_path.py
+++ b/tests/test_path.py
@@ -1,6 +1,7 @@
 import six
-from pytest import mark
 import sqlalchemy as sa
+from pytest import mark
+from sqlalchemy.util.langhelpers import symbol
 from sqlalchemy_utils.path import Path, AttrPath
 from tests import TestCase
 
@@ -41,6 +42,17 @@ class TestAttrPath(TestCase):
         self.Section = Section
         self.SubSection = SubSection
 
+    @mark.parametrize(
+        ('class_', 'path', 'direction'),
+        (
+            ('SubSection', 'section', symbol('MANYTOONE')),
+        )
+    )
+    def test_direction(self, class_, path, direction):
+        assert (
+            AttrPath(getattr(self, class_), path).direction == direction
+        )
+
     def test_invert(self):
         path = ~ AttrPath(self.SubSection, 'section.document')
         assert path.parts == [