Signals sent by django-reversion

django-reversion provides a number of custom signals that can be used to tie-in additional functionality to the version creation mechanism.

Important: Don’t connect to the pre_save or post_save signals of the Version or Revision models directly, use the signals outlined below instead. The pre_save and post_save signals are no longer sent by the Version or Revision models since django-reversion 1.7.

reversion.pre_revision_commit

This signal is triggered just before a revision is saved to the database. It receives the following keyword arguments:

• instances - A list of the model instances in the revision.
• revision - The unsaved Revision model.
• versions - The unsaved Version models in the revision.

reversion.post_revision_commit

This signal is triggered just after a revision is saved to the database. It receives the following keyword arguments:

• instances - A list of the model instances in the revision.
• revision - The saved Revision model.
• versions - The saved Version models in the revision.

Connecting to signals

The signals listed above are sent only once per revision, rather than once per model in the revision. In practice, this means that you should connect to the signals without specifying a sender, as below:

def on_revision_commit(**kwargs):
    pass  # Your signal handler code here.
reversion.post_revision_commit.connect(on_revision_commit)

To execute code only when a revision has been saved for a particular Model, you should inspect the contents of the instances parameter, as below:

def on_revision_commit(instances, **kwargs):
    for instance in instances:
        if isinstance(instance, MyModel):
            pass  # Your signal handler code here.
reversion.post_revision_commit.connect(on_revision_commit)