Creating a new module in magento 2

In magento 2 all modules reside in the folder app/code directory, previously in magento1 there was the concept of local/ community/ core/ folders but that has been removed now.

For creating modules in magento 2 we need at least these 3 files in our module in this directory arrangement.

Step1

Module names in magento 2 are divided into two part “VendorName_ModuleName”
e.g Magento_Contact, Magento_Catalog or Trieffects_Test
first part is the vendor and second part is the actual module.

Let’s take our module name to be “Trieffects_Hello”. First we need to make the folders

app/code/Trieffects/Hello

Step2 – module.xml

Next we need to add the module.xml file

app/code/Trieffects/Hello/etc/module.xml

with following contents

<?xml version="1.0"?>
       <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Module/etc/module.xsd"> 
       <module name="Trieffects_Hello" setup_version="0.0.1"/>
 </config>

Step3 – registration.php

Next need to add a registration.php

app/code/Trieffects/Hello/registration.php

content would be

1 2 3 4 5 6

<?php \Magento\Framework\Component\ComponentRegistrar::register(     \Magento\Framework\Component\ComponentRegistrar::MODULE,     'Trieffects_Hello',     __DIR__ );

Step4

Now an empty module is ready, we now need to enable it.

At this stage if you run the command

php bin/magento module:status

You should see

List of disabled modules:
Trieffects_Hello

This means the module is setup, but it is disabled right now.

To enable the module, run the command

php bin/magento module:enable Trieffects_Hello 

this should enable your module.

After this step, when you open your website in browser you will get an error saying

Please upgrade your database: Run "bin/magento setup:upgrade" from the Magento root directory. 

run the command

bin/magento setup:upgrade

to fix this. At this point you should be all set with a empty module.

Step5 – Routes

Now lets add a route (or url) for our module so that we can display “hello world”
Route’s in magento are divided into 3 parts

http://mymagento.com/index.php/route_id/controller/action

index.php is optional and depends on your magento configuration. If you have .htaccess file work index.php is not required.

To add route we need to add routes.xml file

Trieffects/Hello/etc/frontend/routes.xml

since this is a frontend route, we added it in frontend/ folder else we need to add it to adminhtml/ folder

the content of the file are

 <?xml version="1.0"?> 
  <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
   xsi:noNamespaceSchemaLocation="../../../../../../lib/internal/Magento/Framework/App/etc/routes.xsd"> 
    <router id="standard"> 
       <route id="excellence" frontName="excellence"> <module name="Excellence_Hello" /> 
       </route>
    </router> 
  </config>







We usually keep id and frontName the same, or it might causes some issues.
Here we defined the first part of our route. So till now our route is

www.mymagento.com/trieffects/* 

Next we need to define our controller,action.
Lets assume we want our url to be

www.mymagento.com/trieffects/hello/world

for this we need to create the following folder

Trieffects/Hello/Controller/Hello/World.php

and add the following content in

World.php

<?php

namespace Trieffects\Hello\Controller\Hello;

class World extends \Magento\Framework\App\Action\Action

{

    public function __construct(

        \Magento\Framework\App\Action\Context $context)

    {

        return parent::__construct($context);

    }

     

    public function execute()

    {

        echo 'Hello World';

        exit;

    } 

}







Important 


1. There is another important thing to note, if you miss out controller or action name it automatically defaults to Index. Meaning, a url like www.mymagento.com/trieffects would find path
Trieffects/Hello/Controller/Index/Index.php





2. Another important thing, magento create auto generated files at var/generation/Trieffects/Hello/Controller . So if your noticing that, your making changes to controller and the changes are not showing up. Make sure to delete the cache file generated.