The Zend Framework provides a powerful module system. The module system has three components. They are as follows −

• Module Autoloader − A Module Autoloader is responsible for locating and loading of modules from variety of sources. It can load modules packaged as Phar archives as well. The implementation of the Module Autoloader is located at myapp/vendor/zendframework/zend-loader/src/ModuleAutoloader.php.

• Module Manager − Once the Module Autoloader locates the modules, the module manager fires a sequence of events for each module. The implementation of the Module Manager is located at myapp/vendor/zendframework/zendmodulemanager/src/ModuleManager.php.

• Module Manager Listeners − They can be attached to the events fired by the Module Manager. By attaching to the events of module manager, they can do everything from resolving and loading modules to performing complex work for each modules.

MVC Web Module System

The MVC Web Application in the Zend Framework is usually written as Modules. A single website can contain one or more modules grouped by functionality. The recommended structure for MVC-Oriented module is as follows −

module_root/ 
   Module.php 
   autoload_classmap.php 
   autoload_function.php 
   autoload_register.php 
   config/ 
      module.config.php 
   public/ 
      images/ 
      css/ 
      js/ 
   src/ 
      <module_namespace>/ 
      <code files> 
   test/ 
      phpunit.xml
      bootstrap.php 
      <module_namespace>/ 
         <test code files> 
   view/ 
      <dir-named-after-module-namespace>/ 
         <dir-named-after-a-controller>/ 
            <.phtml files>

The structure is same as discussed in the previous chapter, but here it is generic. The autoload_ files can be used as a default mechanism for autoloading the classes available in the module without using the advanced Module Manager available in the zend-modulemanager.

• autoload_classmap.php − Returns an array of class name and its corresponding filename.

• autoload_function.php − Returns a PHP callback. This can utilize classes returned by autoload_classmap.php.

• autoload_register.php − Registers the PHP callback that is returned by the autoload_function.php.

These autoload files are not required but recommended. In the skeleton application, we have not used the autoload_ files.

Module Class

The Module class should be named Module and the namespace of the module class should be Module name. This will help the Zend Framework to resolve and load the module easily. The Application module code in the skeleton(myapp) application,myapp/module/Application/src/Module.php is as follows −

namespace Application; 
class Module { 
   const VERSION = ''3.0.2dev''; 
   public function getConfig() { 
      return include __DIR__ . ''/../config/module.config.php''; 
   } 
}

The Zend Framework module manager will call the getConfig() function automatically and will do the necessary steps.