Question

Is there anyway to set a global image setting, route, or anything so that all images reference a CDN url without having to update every image? So when I use the HTML helper like this:

$this->Html->img('some_image.jpg');

Instead of referencing /img/some_image.jpg, it will point to:

http://cdn.example.com/img/some_image.jpg

UPDATE

Final solution was simple. Thanks @burzum for the push in the proper direction. Here is what I did.

In AppController I added:

public $helpers = array(
    'Html' => array(
        'className' => 'MyHtml'
    )
);

Then I created the override helper:

<?php
// app/View/Helper/MyHtmlHelper.php
App::uses('HtmlHelper', 'View/Helper');
class MyHtmlHelper extends HtmlHelper {
    // Add your code to override the core HtmlHelper
    public function image($path, $options = array()) {
        $path = 'http://cdn.localhost/'.$path;
        return parent::image($path, $options);
    }
}

Answer 1

Simply overwrite the image() method in a customized helper extending the HtmlHelper and use the 2.1 aliasing feature for helpers:

public $helpers = array(
    'Html' => array(
        'className' => 'MyHtml'
    )
);