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I'm beginning with Zend Framework and I would like to understand Bootstrap file. I've learned all _init methods are executed by default but it seems confusing to me. Anyway that is not what I would like to ask.

A came around the $this->bootstrap('layout'); action and I'm not sure if I understand this. Is this the resource.layout variable in application.ini file? I would like to really understand the bootstrap process in deep.

I'm asking you for step by step explanation.
Thanks in advance!

So this is my bootstrap file:

class Bootstrap extends Zend_Application_Bootstrap_Bootstrap
{
    protected function _initAutoload()
    {
        $moduleLoader = new Zend_Application_Module_Autoloader(array(
            'namespace' => '',
            'basePath' => APPLICATION_PATH
        ));
        return $moduleLoader;
    }

    function _initViewHelpers()
    {
        $this->bootstrap('layout');

        $layout = $this->getResource('layout');
        $view = $layout->getView();
        $view->doctype('XHTML1_STRICT');
        $view->headMeta()->appendHttpEquiv('Content-Type', 'text/html;charset=utf-8');
        $view->headTitle()->setSeparator(' - ');
        $view->headTitle('Zend Framework Tutorial');
    }
}

Best Answer

The line from application.ini

resources.layout[] =

is equivalent to:

_initLayout() {}

in Bootstrap.php

Both of them are initializing new object, and this object is set as a bootstrap param, which is a container for some application resources (values returned by _init methods).

There are executed one by one, so to ensure one resource is initialized before the the current one, you force the order, using:

_initSomeResource() {
    $this->bootstrap('otherResource');
    // ..
    return $someValue; 
}

_initOtherResource() {
    // .. 
}

So the order of instantiating of the resources is:

  1. otherResource
  2. someResource

Now, you may also use:

$bootstrap->getParam('someResource'); // returns $someValue

Note, that you may encounter Circular Dependency error, when you try to execute each other before each one.

You may use as many _init methods you need, but to make them reusable, you may separate them to their own class, implementing Zend_Application_Resource_Abstract class.

There are some out of the box application resources, which you may find in Zend/Application/Resource directory. These are the resources, you are refering from application.ini, i.e.:

resources.view.encoding = "utf-8" ; in application.ini
Zend/Application/Resource/View.php (path to the resource class)
Zend_Application_Resource_View::setEncoding('UTF-8'); // equivalent pseudocode

Hope it's more clear now.

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