magento2.3 controller won't handle post method

Question

This is something I used to be able to do in 2.2, but in 2.3 I can't.

A simple controller to handle a POST method, and only receive and send application/json content type.

It works for GET/PUT methods, but if POST, it will render home page (html).

<?php

namespace <vendor>\<module>\Controller\Api;

class MyApi extends \Magento\Framework\App\Action\Action
{

    public function execute()
    {
        $result = $this->createResultJson();

        $result->setData([
            'message' => 'All Good.'
        ]);

        $result->setHttpResponseCode(200);

        return $result;
    }


    /**
     * @return \Magento\Framework\Controller\ResultInterface|\Magento\Framework\Controller\Result\Json
     */
    protected function createResultJson()
    {
        return $this->resultFactory->create(\Magento\Framework\Controller\ResultFactory::TYPE_JSON);
    }

}

Answer 1

To handle the POST method in your controller class, you have to implement the Magento\Framework\App\Action\HttpPostActionInterface interface:

<?php

namespace Vendor\Module\Controller\Api;

use Magento\Framework\App\Action\HttpPostActionInterface as HttpPostActionInterface;

class MyApi extends \Magento\Framework\App\Action\Action implements HttpPostActionInterface
{
    public function execute()
    {
        // ...
    }
}

You can check how the Login controller does it:

vendor/magento/module-customer/Controller/Ajax/Login.php

Also, you should send the Headers correctly, for example:

"Content-Type": "application/json",
"X-Requested-With": "XMLHttpRequest"

For Get Post Data (FORM DATA) (POSTMAN)

"Content-Type": "multipart/form-data;"

Answer 2

If you cannot change the headers values, you can do as follows:

Import these classes:

use Magento\Framework\App\CsrfAwareActionInterface;
use Magento\Framework\App\RequestInterface;
use Magento\Framework\App\Request\InvalidRequestException;

Implement CsrfAwareActionInterface :

class MyApi extends \Magento\Framework\App\Action\Action implements CsrfAwareActionInterface

And implement the following methods:

public function createCsrfValidationException(RequestInterface $request): ? InvalidRequestException
{
  return null;
}

public function validateForCsrf(RequestInterface $request): ?bool
{
     return true;
}

Source

Answer 3

This solves the problem, but after that your module will not work on Magento 2.2 and earlier https://magento.stackexchange.com/a/255082/75860