Zend_Validate_Db_RecordExists or empty value

Question

I've got a (hopefuly) simple task, and my google fu has failed me. Basically, I've got a form with a select which contains an empty value and then number of ids given content can belong to. What I want to do is - validate if the given ids exist, but only if a value is set. This:

$field = new Zend_Form_Element_Select('field');
$field->addValidator(
    new Zend_Validate_Db_RecordExists(
        array(
            'table' => 'categories',
            'field' => 'id'
        )
));

takes care of the checking if the given id exists, but I'm not able to find any way to omit this if value is empty. One way to do this would be to move this logic to isValid method, but I'm hoping there's nicer way to accomplish this task.

Answer 1

Try to set this form element as not required:

$field->setRequired(false);

When element is not required and is not filled, validators queue won't be run.

Quick example which works for me:

// Zend_Form form body
$this->addElement('select', 'category', array(
        'label' => 'Choose category',
        'required' => false,
        'multiOptions' => array(
                null => 'No category selected',
                '1' => 'One',
                '2' => 'Two',   
        ),
        'validators' => array(
                array('Db_NoRecordExists', false, array(
                        'schema' => 'public',
                        'table' => 'category',
                        'field' => 'id',    
                )), 
        ),
));