email validator

gistfile1.txt

$this->add(array(
    'name' => 'email',
    'required' => true,
    'validators' => array(
        array(
            'name' => 'NotEmpty',
            'options' => array(
                'messages' => array(
                    \Zend\Validator\NotEmpty::IS_EMPTY => 'Email cannot be empty'
                ),
            ),
        ),
        array(
            'name' => 'DoctrineModule\Validator\NoObjectExists',
            'options' => array(
                'object_repository' => $userRepository,
                'fields' => array('email'),
                'messages' => array(
                    'objectFound' => 'An account with this email already exists.'
                )
            )
        )
    )
));