Magento 2 JSON Response – How to Intercept Controller’s JSON Response

interceptorjsonmagento-2.0magento2

I'm trying to intercept a controller returning a JSON object of Magento\Framework\Controller\Result\Json class. The problem is that no matter if I use a plugin or a preference to "catch" the controller response right after it's created to do what I want with it, I always end up with this Json object, and its only public method inherited from Magento\Framework\Controller\AbstractResult is the renderResult method (apart from some setters, which won't help me at all).The JSON string is also a protected property, so I can't access it directly.

So, how can I get the JSON string from the response object? Of course, I could just replicate some of the controller's logic that creates it and use that instead, but I'm trying to avoid this method if possible.

I'm using the develop branch. I based my code on the 0be91a5 commit (Merge pull request #14 from magento-vanilla/PR), but I checked the latest commit (currently it's 74f9337 Merge pull request #81 from magento-firedrakes/MAGETWO-44741) and there are no changes in the Json and AbstractResult classes.

Best Answer

Class \Magento\Framework\Controller\Result\Json has two public methods for work with data. You can add plugin on their methods to modify json related data:

class \MyVendor\MyModule\Controller\Result\JsonPlugin {
   public function beforeSetData($subject, $data, $cycleCheck = false, $options = []) 
   {
       return [ 'data' => $data, 'metadata' => 'sdsd'];
   }
   public function beforeSetJsonData($subject, $jsonData)
   {  
        return '{"data": ' . $jsonData . , ', "metadata": []}';
   }

Related Solutions

Magento – AJAX Request JSON Response Always NULL

Try to edit your layout.xml for the ajax page:

<your_ajax_action>
        <reference name="root">
            <block type="yourajax/block" name="root" output="toHtml" />
        </reference>
</your_ajax_action>

This way, you will force the skipping of the headers, footers and other pages you don't need.

Alternatively you can try to simply echo your response and then exit() after. It is not the Magento way, but it usually works.

Magento 2: Sending a Custom Header/Response from a Controller

First of all, to comply with action controller interface \Magento\Framework\App\ActionInterface::execute(), your action must return an instance of \Magento\Framework\Controller\ResultInterface (\Magento\Framework\App\ResponseInterface is also supported, but is legacy and will be removed in future releases of M2, when all core usages are refactored).

So choose from available implementations of \Magento\Framework\Controller\ResultInterface. The most suitable for custom REST API (assuming it operates with JSON) seems to be \Magento\Framework\Controller\Result\Json. However, if you need something even more custom, consider \Magento\Framework\Controller\Result\Raw.

Working sample:

<?php
namespace VendorName\ModuleName\Controller;

/**
 * Demo of authorization error for custom REST API
 */
class RestAuthorizationDemo extends \Magento\Framework\App\Action\Action
{
    /** @var \Magento\Framework\Controller\Result\JsonFactory */
    protected $jsonResultFactory;

    public function __construct(
        \Magento\Framework\App\Action\Context $context,
        \Magento\Framework\Controller\Result\JsonFactory $jsonResultFactory
    ) {
        parent::__construct($context);
        $this->jsonResultFactory = $jsonResultFactory;
    }

    public function execute()
    {
        /** @var \Magento\Framework\Controller\Result\Json $result */
        $result = $this->jsonResultFactory->create();
        /** You may introduce your own constants for this custom REST API */
        $result->setHttpResponseCode(\Magento\Framework\Webapi\Exception::HTTP_FORBIDDEN);
        $result->setData(['error_message' => __('What are you doing here?')]);
        return $result;
    }
}

The code above will result in response with HTTP status code 403 and body {"error_message":"What are you doing here?"}

Best Answer

Related Solutions

Magento – AJAX Request JSON Response Always NULL

Magento 2: Sending a Custom Header/Response from a Controller

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