Magento 2 Controllers

In Magento 2, controllers are responsible for handling HTTP requests and generating responses. Controllers are essential for building custom functionality in both the frontend and adminhtml (backend) areas.

📂 Where Are Controllers Located?

Controllers are placed inside:

  • Controller/ directory in your module
  • Subfolders: Frontend and Adminhtml
app/code/Bcn/HelloWorld/Controller/Index/Hello.php
app/code/Bcn/HelloWorld/Controller/Adminhtml/Index/Hello.php

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🛣️ Step 1: Define a Route

Create routes.xml in the etc/frontend or etc/adminhtml folder.

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📑 Step 2: Create a Frontend Controller

The following controller responds to the URL: /helloworld/index/hello

// Controller/Index/Hello.php
namespace Bcn\HelloWorld\Controller\Index;

use Magento\Framework\App\Action\Action;
use Magento\Framework\App\Action\Context;
use Magento\Framework\Controller\ResultFactory;

class Hello extends Action
{
    public function __construct(Context $context)
    {
        parent::__construct($context);
    }

    public function execute()
    {
        $result = $this->resultFactory->create(ResultFactory::TYPE_RAW);
        $result->setContents("Hello from Bcn_HelloWorld frontend controller!");
        return $result;
    }
}

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🔐 Step 3: Create an Adminhtml Controller

The following controller will be available in the admin panel at: /admin/helloworld/index/hello

// Controller/Adminhtml/Index/Hello.php
namespace Bcn\HelloWorld\Controller\Adminhtml\Index;

use Magento\Backend\App\Action;
use Magento\Backend\App\Action\Context;
use Magento\Framework\Controller\ResultFactory;

class Hello extends Action
{
    public function __construct(Context $context)
    {
        parent::__construct($context);
    }

    public function execute()
    {
        $result = $this->resultFactory->create(ResultFactory::TYPE_RAW);
        $result->setContents("Hello from Bcn_HelloWorld admin controller!");
        return $result;
    }

    protected function _isAllowed()
    {
        return true; // Use ACL in production
    }
}

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⚙️ Result Types in Magento 2

  • TYPE_PAGE – for full HTML pages
  • TYPE_RAW – for plain text
  • TYPE_JSON – for JSON responses
  • TYPE_REDIRECT – for redirects

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📌 Summary

  • Frontend controllers respond to public URLs
  • Adminhtml controllers are used for backend features
  • Use routes.xml to define front names
  • Always include a secure _isAllowed() method in admin controllers

Controllers are the starting point for any request-based logic. Next, you can integrate Models and Blocks to build dynamic responses.