Remove the attr argument from ManyRelation

Closes #3

bridgekeeper/rule_many_relation_tests.py

@@ -12,7 +12,7 @@ def test_many_relation_to_user():
     u1 = UserFactory(profile__branch__store=s1)
     u2 = UserFactory(profile__branch__store=s2)
     user_branch_in_store = ManyRelation(
-        'branch_set', 'branch', Is(lambda u: u.profile.branch))
+        'branch', Is(lambda u: u.profile.branch))
 
     assert user_branch_in_store.check(u1, s1)
     assert user_branch_in_store.check(u2, s2)
@@ -33,5 +33,5 @@ def test_many_relation_to_user():
 def test_many_relation_never_global():
     user = UserFactory()
     user_branch_in_store = ManyRelation(
-        'branch_set', 'branch', Is(lambda u: u.profile.branch))
+        'branch', Is(lambda u: u.profile.branch))
     assert not user_branch_in_store.check(user)

bridgekeeper/rules.py

@@ -475,16 +475,8 @@ class ManyRelation(Rule):
     across a :class:`~django.db.models.ManyToManyField`, or the remote
     end of a :class:`~django.db.models.ForeignKey`.
 
-    :param attr: Name of a many-object relationship to check. This is
-        the accessor name; the name that you access on a model
-        instance to get a manager for the other side of the
-        relationship. If you are on the reverse side of the relationship
-        (the side where the field is *not* defined), this is typically
-        ``mymodel_set``, where ``mymodel`` is the lowercased model name,
-        unless you've set
-        :attr:`~django.db.models.ForeignKey.related_name`.
-    :type attr: str
-    :param query_attr: Query name to use; that is, the name that you
+    :param query_attr: Name of a many-object relationship to check. This
+        This is the name that you
         use when filtering this relationship using ``.filter()``.
         If you are on the side of the relationship where the field
         is defined, this is typically the lowercased model name (e.g.
@@ -500,18 +492,17 @@ class ManyRelation(Rule):
     relationship with their agency::
 
         perms['foo.view_customer'] = ManyRelation(
-            'agency_set', 'agency', Is(lambda user: user.agency))
+            'agency', Is(lambda user: user.agency))
     """
 
-    def __init__(self, attr, query_attr, rule):
+    def __init__(self, query_attr, rule):
         # TODO: add support for 'all' as well as 'exists'
-        self.attr = attr
         self.query_attr = query_attr
         self.rule = rule
 
     def __repr__(self):
-        return "ManyRelation({!r}, {!r}, {!r})".format(
-            self.attr, self.query_attr, self.rule)
+        return "ManyRelation({!r}, {!r})".format(
+            self.query_attr, self.rule)
 
     def query(self, user):
         # Unfortunately you can't use Q objects on a relation, only proper
@@ -527,5 +518,8 @@ def check(self, user, instance=None):
         related_q = self.rule.query(user)
         if related_q is UNIVERSAL or related_q is EMPTY:
             return related_q
-        related_manager = getattr(instance, self.attr)
+        attr = instance.__class__._meta.get_field(
+            self.query_attr,
+        ).get_accessor_name()
+        related_manager = getattr(instance, attr)
         return related_manager.filter(related_q).exists()

docs/changelog.rst

@@ -5,6 +5,7 @@ dev
 ---
 
 - **Breaking change:** :class:`~bridgekeeper.rules.Relation` and :class:`~bridgekeeper.rules.ManyRelation` no longer require the model class on the other side of the relation to be passed in as an argument.
+- **Breaking change:** :class:`~bridgekeeper.rules.ManyRelation` removes the ``attr`` argument, requiring only ``query_attr``.
 - **Breaking change:** Python 3.4 and Django 1.11 are no longer supported.
 
 0.7