Magento 2 How to return JSON object in rest response

Question

I want to return the JSON response suggested by the mobile app developer. My custom rest API currently returning responses in the below format.

[{
"status": true,
"data": [
  {
    "entity_id": "3",
    "name": "Test category",
    "icon_name": "test",
    "category_url": "http://127.0.0.1/magento/pub/catalog/category/view/s/test-category/id/3/",
    "button_name": "Sell Now"
  },
  {
    "entity_id": "4",
    "name": "magento Test",
    "icon_name": null,
    "category_url": "http://127.0.0.1/magento/pub/catalog/category/view/s/magento-test/id/4/",
    "button_name": "Sell Now"
  }
]}]

And below is the expected result:

 {"status": true,
    "data": [
      {
        "entity_id": "3",
        "name": "Test category",
        "icon_name": "test",
        "category_url": "http://127.0.0.1/magento/pub/catalog/category/view/s/test-category/id/3/",
        "button_name": "Sell Now"
      },
      {
        "entity_id": "4",
        "name": "magento Test",
        "icon_name": null,
        "category_url": "http://127.0.0.1/magento/pub/catalog/category/view/s/magento-test/id/4/",
        "button_name": "Sell Now"
      }
    ]
  }

The code that I have implemented: Interface:

 /**
     * Get category collection
     *
     * @api
     * @return string
     */
    public function getCategoryCollection();

Model:

public function getCategoryCollection()
      {
          try
          {
            $collection = $this->_categoryCollectionFactory->create();
            $collection->addAttributeToSelect('*');         
            $collection->addIsActiveFilter();          
            $i=0;
            if(count($collection)){
              foreach ($collection as $category){
                $data[$i]=["entity_id" => $category->getId(),
                            "name"=> $category->getName(),
                            "icon_name" => $category->getData('category_icon_name'),
                            "category_url" => $category->getUrl(),
                            "button_name" => "Sell Now"
                            ];
                      $i++;
                }
                $output = ["status"=>true, "data"=>$data];
            }
            else{
              $output=["status"=>false,"message"=>"No Category found"];
            }            
            return [$output]; 
          }
          catch (\Exception $exception) { 
            $output=["status"=> false, 'message' => $exception->getMessage()];
            return [$output];
          }
      }

I got one solution to add the below code but using that might be not appropriate:

print_r(json_encode($output)); 
die();

Any help will be grateful.

Answer 1

Try sending response like this

$this->response is object of \Magento\Framework\Webapi\Rest\Response class

  $this->response->setHeader('Content-Type', 'application/json', true)
                ->setBody(json_encode($output))
                ->sendResponse();