Fixed #2445 -- Allowed limit_choices_to attribute to be a callable.

ForeignKey or ManyToManyField attribute ``limit_choices_to`` can now
be a callable that returns either a ``Q`` object or a dict.

Thanks michael at actrix.gen.nz for the original suggestion.

1 files changed, 11 insertions, 0 deletions

diff --git a/django/forms/fields.py b/django/forms/fields.py
index 1ce36c199c..629aa69c5d 100644
--- a/django/forms/fields.py
+++ b/django/forms/fields.py
@@ -170,6 +170,17 @@ class Field(object):
         """
         return {}
 
+    def get_limit_choices_to(self):
+        """
+        Returns ``limit_choices_to`` for this form field.
+
+        If it is a callable, it will be invoked and the result will be
+        returned.
+        """
+        if callable(self.limit_choices_to):
+            return self.limit_choices_to()
+        return self.limit_choices_to
+
     def _has_changed(self, initial, data):
         """
         Return True if data differs from initial.