How Magento 2 Controllers Work

Creating a controller in Magento 2 involves setting up various files and configurations to handle incoming requests, process them, and render responses. Magento 2 controllers come in two types: frontend (for customer-facing operations) and backend (for admin operations). While they share a similar setup, backend controllers often include permission checks like form keys.

How Magento 2 Controllers Work
Controllers receive and process requests from users (e.g., web browsers). The FrontController (`Magento\Framework\App\FrontController`) is the entry point for requests, determining the appropriate route, controller, and action method.
Example URL:

				
					http://example.com/route_name/controller/action

route_name: Defined in routes.xml
controller: Subfolder inside the Controller directory
action: Class with an execute() method that processes the request

Steps to Create a Controller in Magento 2
Step 1: Create the routes.xml File
This file defines the route name and links it to the module.
File: app/code/Abbas/HelloWorld/etc/frontend/routes.xml

				
					<?xml version="1.0" ?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:App/etc/routes.xsd">
    <router id="standard">
        <route frontName="helloworld" id="helloworld">
            <module name="Abbas_HelloWorld"/>
        </route>
    </router>
</config>

Step 2: Create the Controller File
In this example, we’ll create a controller Index with an execute() method to define the main functionality.
File: app/code/Abbas/HelloWorld/Controller/Index/Index.php

				
					<?php 

namespace Abbas\HelloWorld\Controller\Index;

class Index extends \Magento\Framework\App\Action\Action
{
    protected $_pageFactory;

    public function __construct(
        \Magento\Framework\App\Action\Context $context,
        \Magento\Framework\View\Result\PageFactory $pageFactory
    ) {
        $this->_pageFactory = $pageFactory;
        parent::__construct($context);
    }

    public function execute()
    {
        return $this->_pageFactory->create();
    }
}

This controller extends Magento\Framework\App\Action\Action and defines the execute() method, where you can add logic to process the request.

Step 3: Create the Layout XML File
Define the page layout and template block for the controller.
File: app/code/Abbas/HelloWorld/view/frontend/layout/helloworld_index_index.xml

				
					<?xml version="1.0"?>
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" layout="1column" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
    <referenceContainer name="content">
        <block class="Abbas\HelloWorld\Block\Index" name="helloworld_index_index" template="Abbas_HelloWorld::index.phtml" />
    </referenceContainer>
</page>

Step 4: Create the Block Class
This block class will handle data and business logic for your template.
File: app/code/Abbas/HelloWorld/Block/Index.php

				
					<?php

namespace Abbas\HelloWorld\Block;

class Index extends \Magento\Framework\View\Element\Template
{
}

Step 5: Create the Template File
This .phtml template file defines what is displayed on the page.
File: app/code/Abbas/HelloWorld/view/frontend/templates/index.phtml

				
					<h2>Welcome to Magento Controller</h2>

Step 6: Flush Magento Cache
Clear the cache to make sure the new controller and other configurations are loaded.

				
					bin/magento cache:flush

Step 7: Test the Controller
Visit the URL:

				
					http://example.com/helloworld/index/index

Or use the shorter format:

				
					http://example.com/helloworld

Thanks for reading

Mohamed Abbas

Technical Lead | Magento Architect