Imported Upstream version 0.4upstream/0.4

1 files changed, 51 insertions, 0 deletions

diff --git a/tagging/registry.py b/tagging/registry.py
new file mode 100644
index 0000000..30c00ae
--- /dev/null
+++ b/tagging/registry.py
@@ -0,0 +1,51 @@
+"""
+Registery for tagging.
+"""
+from tagging.managers import TagDescriptor
+from tagging.managers import ModelTaggedItemManager
+
+registry = []
+
+
+class AlreadyRegistered(Exception):
+    """
+    An attempt was made to register a model more than once.
+    """
+    pass
+
+
+def register(model, tag_descriptor_attr='tags',
+             tagged_item_manager_attr='tagged'):
+    """
+    Sets the given model class up for working with tags.
+    """
+    if model in registry:
+        raise AlreadyRegistered(
+            "The model '%s' has already been registered." %
+            model._meta.object_name)
+    if hasattr(model, tag_descriptor_attr):
+        raise AttributeError(
+            "'%s' already has an attribute '%s'. You must "
+            "provide a custom tag_descriptor_attr to register." % (
+                model._meta.object_name,
+                tag_descriptor_attr,
+            )
+        )
+    if hasattr(model, tagged_item_manager_attr):
+        raise AttributeError(
+            "'%s' already has an attribute '%s'. You must "
+            "provide a custom tagged_item_manager_attr to register." % (
+                model._meta.object_name,
+                tagged_item_manager_attr,
+            )
+        )
+
+    # Add tag descriptor
+    setattr(model, tag_descriptor_attr, TagDescriptor())
+
+    # Add custom manager
+    ModelTaggedItemManager().contribute_to_class(
+        model, tagged_item_manager_attr)
+
+    # Finally register in registry
+    registry.append(model)