Writing your own validators

Yii provides a good set of built-in form validators that cover the most typical of developer's needs and are highly configurable. However, in some cases, the developer may face a need to create a custom validator.

A good example would be the website ownership validation. For a few of their services, Google requires you to upload a file with the name and content specified to your website, and then checks if it is there. We will do the same.

There are two ways to achieve it; you can use a class method as a validator, or the second way is to create a separate class.

Getting ready

Create a new application using yiic webapp as described in the official guide.

How to do it...

1. We will start with the class method approach. First, we need to implement a form model. So, create protected/models/SiteConfirmation.php as follows:

   <?php
   class SiteConfirmation extends CFormModel {
      public $url;
   
      public function rules()
      {
         return array(
            array('url', 'confirm...