Description of problem: If user implements his own validation through Automate methods, there is no way to display the methods in Dialog User in a consistent way with other validation methods. The only way to inform about an error is to display the error message inside of TextBox/TextArea. The goal is to provide a way to display error messages from Automate methods in Dialog User.
Please assess the impact of this issue and update the severity accordingly. Please refer to https://bugzilla.redhat.com/page.cgi?id=fields.html#bug_severity for a reminder on each severity's definition. If it's something like a tracker bug where it doesn't matter, please set the severity to Low.