Sometimes we want to alter the nodes defined by other modules or created with CCK. Our module might add some specific logic or fields to nodes. It’s great to be able to store and retrieve our data in the node object. It makes our data easily accessible throughout the website.

In Drupal 6 we had the hook_nodeapi that allowed us to change nodes defined by other modules. Drupal 7 dumped hook_nodeapi and gave us specific hooks in return. So how about that?