如何强制204 rest API返回内容？

Question

I know that 204 means that the server has understood the request but there is no content available. But I think is wrong prevent to the developer return a json message like this:
return json_encode(array("mex" => "no content"));

What I need is return also a json when the API return 204 in the header. I don't want use 200 in this case 'cause this means that there is a content returned.

Also the 404 is not appropriate 'cause this means the resource doesn't exits.
Anyidea to do this?
This is my code:

http_response_code(204);
return json_encode(array("mex" => "no content"));

Answer 1

You can't. The HTTP specification states that:

The 204 response MUST NOT include a message-body, and thus is always terminated by the first empty line after the header fields.

Attempting to include content in a 204 response will cause many HTTP clients to malfunction. If you want to include a message with your response, you will need to use a response code other than 204.