How to discard changes in Rules module

Question

Depending on a condition I want a node's changed content not to be overwritten on the old content. That is old content should be retained and new one discarded so that node does not change.

Which action should I add? I've tried many but everytime a user saves a node, it is permanently changing the node's content.

Answer 1

Create a rule for the "Content is going to be saved" event, and add a "Execute custom PHP code" action. The code you write have access to some variables by reference: $node, $node_unchanged, $user, $author, $author_unchanged, and $user.

For example, you can use the following code to set the title as it was before the node was edited.

$node->title = $node_unchanged->title;

return array('node' => $node);

Similar code is usable in the version for Drupal 7 of the Rules module; what changes is the variables to which the code has access.