CQ5.5 comes with a new undo/redo feature for page editing. You are now able to undo/redo any change that you made to a page. It’s a great new feature that however also comes with a bit of a learning curve if you want to use it correctly in your CQ project.
Any new component you write needs to be tested for undo/redo. Once tested and your satisfied it works correctly, you need to add your component to the whitelist of undo/redo components, otherwise a nasty popup will show up everytime somebody hits ctrl-z to undo any changes. To add your component to the whitelist, go to
You’ll find a property cq.wcm.undo.whitelist, add your component to this list to make the message go away. Unfortunately, this is the only place to set this setting and may cause problems in the future when you upgrade CQ since everything in /libs may be overwritten by a hotfix.
Undo/Redo information for any text is stored in the browser either on the window or in a cookie, however, if you change an image, the information is stored in /var/undo. This only works if you have sufficient rights to store data in this location, by default, this is only granted to administrators, so regular users may not be able to undo/redo changes on images withing CQ. Also note, this may fill up the repository quickly since a copy of the image is stored in that location.
Undo/Redo can also be dangerous if multiple people work on the same page at any given time. There is no mechanism to make sure multiple users do not step on each other when making changes. Now with undo/redo, you can make large changes quickly and you may therefore alter a page in a way that you did not intend if there are other modifications from other users. You can turn undo/redo off altogether by setting the cq.wcm.undo.enabled property to false.
If you’re users don’t like the flashy style of CQ to show you what has been undone on a page, you can set the cq.wcm.undo.markermode property to select instead. This will just select the component that has been undone instead.
For more information about the undo/redo service please consult http://dev.day.com/docs/en/cq/current/administering/config_undo.html