(lines 859-865 of DataObjectManager.php)
Ok so I've found out how to add a required fields type of validation to DOM popup thanks to [url=http://www.silverstripe.org/dataobjectmanager-module-forum/show/9340]this post[/url]. What I want to do now is add validation which ensures that a url is in url format and a price is a currency symbol followed by numbers.
Any suggestions? I've been searching online and in the code to no avail.