Z_Form :: Adding a custom error message to zend_form inside Action Controller

I'm new to ZF and I'm discovering how to use Zend_Form and utilize it's capability like validating and filtering input values. I already know开发者_Go百科 the basic of Zend_form like building a form and add element into it. My problem is that I want to add a custom error message to form element and I want to define that message inside the action controller that instantiated the form. I want to defined the error message inside the controller because I need to perform a validation against the database. For example checking if the username/email already exist in the database. I tried googling and that's leads me to setErrorMessage method of zend_form but when I try to use it, the error message is not showing at all... I also tried zend_form->setError and still no error displaying in the view script. Is my idea of setting custom error in the action controller correct or this should be done the other way?

Are you using Zend_Validate_Db_RecordExists?

Something like this should work:

 $form->getElement('username')->getValidator("RecordExists")->setMessage('This username exists',
                Zend_Validate_Db_RecordExists::ERROR_RECORD_FOUND
            );

This works for me:

$form->getElement('username')->addError('This username exists.');