The Module Class

By default, the Zend Framework 2 module system simply expects each module name to be capable of resolving to an object instance. The default module resolver, Zend\ModuleManager\Listener\ModuleResolverListener, simply instantiates an instance of {moduleName}\Module for each enabled module.

A Minimal Module

As an example, provided the module name “MyModule”, Zend\ModuleManager\Listener\ModuleResolverListener will simply expect the class MyModule\Module to be available. It relies on a registered autoloader (typically Zend\Loader\ModuleAutoloader) to find and include the MyModule\Module class if it isn’t already available.

The directory structure of a module named “MyModule” might start out looking something like this:

MyModule/
    Module.php

Within Module.php, you define your MyModule\Module class:

namespace MyModule;

class Module
{
}

Though it will not serve any purpose at this point, this “MyModule” module now has everything required to be considered a valid module and to be loaded by the module system!

This Module class serves as the single entry point for ModuleManager listeners to interact with a module. From within this simple - yet powerful - class, modules can override or provide additional application configuration, perform initialization tasks such as registering autoloader(s), services and event listeners, declaring dependencies, and much more.

A Typical Module Class

The following example shows a more typical usage of the Module class:

namespace MyModule;

class Module
{
    public function getAutoloaderConfig()
    {
        return array(
            'Zend\Loader\ClassMapAutoloader' => array(
                __DIR__ . '/autoload_classmap.php',
            ),
            'Zend\Loader\StandardAutoloader' => array(
                'namespaces' => array(
                    __NAMESPACE__ => __DIR__ . '/src/' . __NAMESPACE__,
                ),
            ),
        );
    }

    public function getConfig()
    {
        return include __DIR__ . '/config/module.config.php';
    }
}

For a list of the provided module manager listeners and the interfaces and methods that Module classes may implement in order to interact with the module manager and application, see the module manager listeners and the module mananger events documentations.

The “loadModules.post” Event

It is not safe for a module to assume that any other modules have already been loaded at the time init() method is called. If your module needs to perform any actions after all other modules have been loaded, the module manager’s “loadModules.post” event makes this easy.

Note

For more information on methods like init() and getConfig(), refer to the module manager listeners documentation.

Sample Usage of “loadModules.post” Event

use Zend\EventManager\EventInterface as Event;
use Zend\ModuleManager\ModuleManager;

class Module
{
    public function init(ModuleManager $moduleManager)
    {
        // Remember to keep the init() method as lightweight as possible
        $events = $moduleManager->getEventManager();
        $events->attach('loadModules.post', array($this, 'modulesLoaded'));
    }

    public function modulesLoaded(Event $e)
    {
        // This method is called once all modules are loaded.
        $moduleManager = $e->getTarget();
        $loadedModules = $moduleManager->getLoadedModules();
        // To get the configuration from another module named 'FooModule'
        $config = $moduleManager->getModule('FooModule')->getConfig();
    }
}

Note

The init() method is called for every module implementing this feature, on every page request, and should only be used for performing lightweight tasks such as registering event listeners.

The MVC “bootstrap” Event

If you are writing an MVC-oriented module for Zend Framework 2, you may need access to additional parts of the application in your Module class such as the instance of Zend\Mvc\Application or its registered ServiceManager instance. For this, you may utilize the MVC “bootstrap” event. The bootstrap event is triggered after the “loadModule.post” event, once $application->bootstrap() is called.

Sample Usage of the MVC “bootstrap” Event

use Zend\EventManager\EventInterface as Event;

class Module
{
    public function onBootstrap(Event $e)
    {
        // This method is called once the MVC bootstrapping is complete
        $application = $e->getApplication();
        $services    = $application->getServiceManager();
    }
}

Note

The onBootstrap() method is called for every module implementing this feature, on every page request, and should only be used for performing lightweight tasks such as registering event listeners.