Overriding a controller in Magento 2

[dbsdsun]

This post walks through the process to override a controller in Magento 2. Code is available at https://github.com/dbsdsun/magento2Override.

There are a few steps to override a Magento 2 controller.

1. Building a Magento 2 extension structure
2. Setting preference in di.xml
3. Defining an overriding controller class

Step 1. Building a Magento 2 extension structure

Building directories as following:

magento2 --- app --- code
                       |--- Sample --- HelloWorld
                       | --- Controller
                       | --- etc
                              | --- module.xml
                              | --- di.xml

Creating module.xml to define a Magento2 extension:

<?xml version="1.0"?>
<!--
/**
 * Created by wilson.sun330@gmail.com
 * Date: 13/05/2015
 * Time: 5:02 PM
 */
-->
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../../../../lib/internal/Magento/Framework/Module/etc/module.xsd">
    <module name="Sample_HelloWorld" setup_version="0.0.1"/>
</config>

Step 2. Setting preference in di.xml

Creating di.xml to refer the overriding class:

<?xml version="1.0"?>
<!--
/**
 * Created by wilson.sun330@gmail.com
 * Date: 13/05/2015
* Time: 5:02 PM
*/
-->
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../../../../lib/internal/Magento/Framework/ObjectManager/etc/config.xsd">
<preference for="Magento\Cms\Controller\Index\Index" type="Sample\HelloWorld\Controller\Index\ExtendIndex" /> 
</config>

 Sample\HelloWorld\Controller\Index\ExtendIndex will be used to override Magento\Cms\Controller\Index\Index, which is the homepage in original Magento 2.

Step 3. Defining an overriding controller class

Under magento2/app/code/Sample/HelloWorld/Controller, defining ExtendIndex.php as following.

<?php
/**
 * Created by wilson.sun330@gmail.com
 * Date: 13/05/2015
 * Time: 5:02 PM
 */
namespace Sample\HelloWorld\Controller\Index;
class ExtendIndex extends \Magento\Cms\Controller\Index\Index
{
    public function execute($coreRoute = null)
    {
        $this->messageManager->addSuccess('Message from new controller.');
        return parent::execute($coreRoute);
    }
} 

ExtendIndex.php redefines function execute() to override the function in \Magento\Cms\Controller\Index\Index. The new execute() adds a message to homepage, but it may also implements a complex logic.

[UBojjaiah]

Hi,

it's working fine.

Please let me know how to overriding a adminhtml controller in Magento 2 ?

[dbsdsun]

http://community.magento.com/t5/Programming-Questions/Override-an-admin-controller-in-Magento-2/m-p/...

[Screenname_ho]

I think  directories building  maybe was wrong. /etc and /controller same level with /sample?

[Screenname_ho]

Very good. thank you so much

[Mageplaza]

To rewrite controller, you can do it by using preference. It mean that you need to put a rule in your router config using before attribute.

Open Mageplaza/HelloWorld/etc/di.xml insert the following block of code inside <config> tag rewrite controller in Magento 2

<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../../../../lib/internal/Magento/Framework/ObjectManager/etc/config.xsd">

<router id="standard">
    <route id="mageplaza" frontName="hello">
       <module name="Mageplaza_HelloWorld" before="Magento_Customer" />
    </route>
</router>

</config>

This will completely change controller/action of module Magento_Customer with your controller code, so you should extend rewrited controller and make a change on the function which you want. Also, the controller and action in your module must have same name with rewrited controller/action. For example, if you want to rewrite controller:Magento\Customer\Controller\Account\Create.php

You have to register a router like above and create a controller:

NameSpace\ModuleName\Controller\Account\Create.php