Yii - Modules

A module is an entity that has its own models, views, controllers, and possibly other modules. It is practically an apppcation inside the apppcation.

Step 1 − Create a folder called modules inside your project root. Inside the modules folder, create a folder named hello. This will be the basic folder for our Hello module.

Step 2 − Inside the hello folder, create a file Hello.php with the following code.

<?php
   namespace appmoduleshello;
   class Hello extends yiiaseModule {
      pubpc function init() {
         parent::init();
      }
   }
?>

We have just created a module class. This should be located under the module s base path. Every time a module is accessed, an instance of the correspondent module class is created. The init() function is for initiapzing the module s properties.

Step 3 − Now, add two more directories inside the hello folder − controllers and views. Add a CustomController.php file to the controller’s folder.

<?php
   namespace appmoduleshellocontrollers;
   use yiiwebController;
   class CustomController extends Controller {
      pubpc function actionGreet() {
         return $this->render( greet );
      }
   }
?>

When creating a module, a convention is to put the controller classes into the controller’s directory of the module s base path. We have just defined the actionGreet function, that just returns a greet view.

Views in the module should be put in the views folder of the module s base path. If views are rendered by a controller, they should be located in the folder corresponding to the controllerID. Add custom folder to the views folder.

Step 4 − Inside the custom directory, create a file called greet.php with the following code.

<h1>Hello world from custom module!</h1>

We have just created a View for our actionGreet. To use this newly created module, we should configure the apppcation. We should add our module to the modules property of the apppcation.

Step 5 − Modify the config/web.php file.

<?php
   $params = require(__DIR__ .  /params.php );
   $config = [
       id  =>  basic ,
       basePath  => dirname(__DIR__),
       bootstrap  => [ log ],
       components  => [
          request  => [
            // !!! insert a secret key in the following (if it is empty) - this is
               //required by cookie vapdation
             cookieVapdationKey  =>  ymoaYrebZHa8gURuopoHGlK8fLXCKjO ,
         ],
          cache  => [
             class  =>  yiicachingFileCache ,
         ],
          user  => [
             identityClass  =>  appmodelsUser ,
             enableAutoLogin  => true,
         ],
          errorHandler  => [
             errorAction  =>  site/error ,
         ],
          mailer  => [
             class  =>  yiiswiftmailerMailer ,
            // send all mails to a file by default. You have to set
            //  useFileTransport  to false and configure a transport
            // for the mailer to send real emails.
             useFileTransport  => true,
         ],
          log  => [
             traceLevel  => YII_DEBUG ? 3 : 0,
             targets  => [
               [
                   class  =>  yiilogFileTarget ,
                   levels  => [ error ,  warning ],
               ],
            ],
         ],
          db  => require(__DIR__ .  /db.php ),
      ],
       modules  => [
          hello  => [
             class  =>  appmoduleshelloHello , 
         ],
      ],
       params  => $params,
   ];
   if (YII_ENV_DEV) {
      // configuration adjustments for  dev  environment
      $config[ bootstrap ][] =  debug ;
      $config[ modules ][ debug ] = [
          class  =>  yiidebugModule ,
      ];
      $config[ bootstrap ][] =  gii ;
      $config[ modules ][ gii ] = [
          class  =>  yiigiiModule ,
      ];
   }
   return $config;
?>

A route for a module s controller must begin with the module ID followed by the controller ID and action ID.

Step 6 − To run the actionGreet in our apppcation, we should use the following route.

hello/custom/greet

Where hello is a module ID, custom is a controller ID and greet is an action ID.

Step 7 − Now, type http://localhost:8080/index.php?r=hello/custom/greet and you will see the following output.

Important Points

Modules should −

Be used in large apppcations. You should spanide its features into several groups. Each feature group can be developed as a module.

Be reusable. Some commonly used features, as SEO management or blog management, can be developed as modules, so that you can easily reuse them in future projects.