Are you saying that if you click on the "Submit Media" button it's validating the title? I'm a little skeptical, since the Video class doesn't extend ActionSupport and shouldn't support validation at *all*.
The problem is whenever the "Submit Publication" button is clicked, the validator also validates the "title" field for the Video section. Which is something I don't understand.
Since the validation xml is named under "Book-validation.xml", isn't it suppose to validate only fields that belong to the Book action class? Or am I having the wrong concept, that the validation just looks at the field name in the jsp and validate it as long as it matches?
It's not validating the video title--it's displaying the validation message for book title, because you have no way of differentiating between the two title fields. S2 validation is field-based, not form-based. You have the same field name in two forms. The action's fieldErrors() map is at the page level (not form). So the <s:textfield> tag checks for "title" errors--which it finds. Twice.