For OpenID support I implemented a DataObjectDecorator, but I couldn't figure out how I can add a custom validator to it.
I need to ensure that the entered OpenID is unique so that only one user account is linked to a specific OpenID. Is that somehow possible?
The only way I know about is to use the augmentDatabase() method to add an unique-index to the database (adding it to extraDBFields() 'indexes' doesn't work) but in that way I can't output an error-message.
Does someone know how this can be solved?
Thanks a lot,
Markus