Creating Custom Validators

Let's create simple url validator. You can download the source code of this article from here.

Create the file library/My/Validate/SimpleUrl.php with the following content.

<?php
require_once 'Zend/Validate/Abstract.php';
require_once 'Zend/Validate/Hostname.php';
class My_Validate_SimpleUrl extends Zend_Validate_Abstract
{
    const MSG_INVALID_URL = 'notValidUrl';
    const MSG_INVALID_HOSTNAME = 'notValidHostname';
 
    const PATTERN_URL =
        '/^(https?:\\/\\/)?([^:\\/]+)(:[1-9][0-9]{0,4})?(\\/.*)?$/';
    const SUBPATTERN_HOSTNAME_INDEX = 2;
 
    protected $_messageVariables = array(
        'hostname' => '_hostname'
    );
 
    protected $_messageTemplates = array(
        self::MSG_INVALID_URL => "'%value%' is not a valid url",
        self::MSG_INVALID_HOSTNAME => "'%hostname%' is not a valid hostname"
    );
 
    protected $_hostname = '';
 
    public function isValid($value)
    {
        $this->_setValue($value);
 
        $valueString = (string) $value;
        $status = @preg_match(self::PATTERN_URL, $valueString, $matches);
        if (!$status) {
            $this->_error(self::MSG_INVALID_URL);
            return false;
        }
 
        $hostname = $matches[self::SUBPATTERN_HOSTNAME_INDEX];
        $this->_hostname = $hostname;
        $option = Zend_Validate_Hostname::ALLOW_DNS |
                  Zend_Validate_Hostname::ALLOW_IP;
        $hostname_validate = new Zend_Validate_Hostname($option);
        $status = $hostname_validate->isValid($hostname);
        if (!$status) {
            $this->_error(self::MSG_INVALID_HOSTNAME);
            return false;
        }
        return true;
    }
}

Add the simple url validator to form object like the following.

        $form = new Zend_Form();
        $form->addElementPrefixPath('My_Validate', 'My/Validate/',
                                    Zend_Form_Element::VALIDATE)
             ->setAction($this->_request->getBaseUrl() . '/index/profile')
             ->setMethod('post');
        //...
        $url = $form->createElement('text', 'url');
        $url->setLabel('URL')
            //...
            ->addValidator('simpleUrl', false);
        //...

You can add your validators to element objects like the following.

        $url->addPrefixPath('My_Validate', 'My/Validate/',
                               Zend_Form_Element::VALIDATE)

Let's access your web server and check the url validation.