Custom Error Pages for CakePHP Plugin

I'm working with CakePHP 1.3 and I'm looking to have any errors (missing controller, missing page, etc) that contain an /admin/ prefix to come from one of my plugins (using a plugin layout) as opposed to being served using my web sites default.c开发者_如何学Pythontp layout.

Where is the best place to put the code for this?

I was able to solve this by overloading the the _outputMessage() function within ErrorHandler by saving the following as app/app_error.php

<?php

class AppError extends ErrorHandler {

    function _outputMessage( $template ) {

        $url = $this->controller->params['url']['url'];
        if( substr( $url, 0, 6 ) == 'admin/' ) {
            $this->controller->layout = 'admin_default';
        }

        parent::_outputMessage( $template );
    }
}
?>