Zend_Layout allows you to use any class implementing Zend_View_Interface or extending Zend_View_Abstract for rendering your layout script. Simply pass in your custom view object as a parameter to the constructor/startMvc(), or set it using the setView() accessor:

$view = new My_Custom_View();
$layout->setView($view);

$placeholders = new Zend_View_Helper_Placeholder();
$layoutVars   = $placeholders->placeholder('Zend_Layout')->getArrayCopy();

When used with the MVC components, Zend_Layout registers a front controller plugin that renders the layout as the last action prior to exiting the dispatch loop. In most cases, the default plugin will be suitable, but should you desire to write your own, you can specify the name of the plugin class to load by passing the pluginClass option to the startMvc() method.

Any plugin class you write for this purpose will need to extend Zend_Controller_Plugin_Abstract, and should accept a layout object instance as an argument to the constructor. Otherwise, the details of your implementation are up to you.

The default plugin class used is Zend_Layout_Controller_Plugin_Layout.

When used with the MVC components, Zend_Layout registers an action controller helper with the helper broker. The default helper, Zend_Layout_Controller_Action_Helper_Layout, acts as a dumb proxy to the layout object instance itself, and should be suitable for most use cases.

Should you feel the need to write custom functionality, simply write an action helper class extending Zend_Controller_Action_Helper_Abstract and pass the class name as the helperClass option to the startMvc() method. Details of the implementation are up to you.

Zend_Layout uses Zend_Filter_Inflector to establish a filter chain for translating a layout name to a layout script path. By default, it uses the rules 'Word_CamelCaseToDash' followed by 'StringToLower', and the suffix 'phtml' to transform the name to a path. As some examples:

You have three options for modifying inflection: modify the inflection target and/or view suffix via Zend_Layout accessors, modify the inflector rules and target of the inflector associated with the Zend_Layout instance, or create your own inflector instance and pass it to Zend_Layout::setInflector().

// Set the inflector target:
$layout->setInflectorTarget('layouts/:script.:suffix');

// Set the layout view script suffix:
$layout->setViewSuffix('php');

$layout->getInflector()->setTarget('layouts/:script.:suffix')
                       ->setStaticRule('suffix', 'html')
                       ->setFilterRule(array('Word_CamelCaseToUnderscore'));

$inflector = new Zend_Filter_Inflector('layouts/:script.:suffix');
$inflector->addRules(array(
    ':script' => array('Word_CamelCaseToUnderscore'),
    'suffix'  => 'html'
));
$layout->setInflector($inflector);