Popular:
 Building Resilient Systems on AWS: Learn how to design and implement a resilient, highly available, fault-tolerant infrastructure on AWS.

PHP: Get POST JSON

By  on  

My recent work at Mozilla has me creating an OAuth-like authentication transaction between Bugzilla and Phabricator.  This task has thrust me back into the world of PHP, a language I haven't touched much (since version ~5.2) outside of creating WordPress themes and plugins for this blog.  Coming back to a language you haven't touched in years feels like a completely new experience; you notice patterns and methods that you wouldn't have guessed of in years past.

Part of the authentication transaction requires Phabricator to receive a POST request that contains JSON data.  I had expected the data to land in $_POST but the variable was empty; how the hell do I get the POST data?  To get POST JSON with PHP, you use the following:

# Get JSON as a string
$json_str = file_get_contents('php://input');

# Get as an object
$json_obj = json_decode($json_str);

file_get_contents, which I though was only used to retrieve content from local files or traditional URLs, allows you to use the special php://input address to retrieve JSON data as a string.  From there you use json_decode to turn the JSON string into a workable object/array.

It makes sense that the JSON isn't handled via normal $_POST since there's really no key, per se; essentially you just need the "blob" of data as a whole, which is provided by php://input.  You can test the JSON+POST handling with cURL.

Request Metrics real user monitoring
Request Metrics real user monitoring
Request Metrics real user monitoring
Request Metrics real user monitoring

Recent Features

Incredible Demos

  • By
    HTML5 Placeholder Styling with CSS

    Last week I showed you how you could style selected text with CSS. I've searched for more interesting CSS style properties and found another: INPUT placeholder styling. Let me show you how to style placeholder text within INPUTelements with some unique CSS code. The CSS Firefox...

  • By
    Image Reflections with CSS

    Image reflection is a great way to subtly spice up an image.  The first method of creating these reflections was baking them right into the images themselves.  Within the past few years, we've introduced JavaScript strategies and CANVAS alternatives to achieve image reflections without...

Discussion

  1. Lorenzo

    I always use this line of code:

    @json_decode(($stream = fopen('php://input', 'r')) !== false ? stream_get_contents($stream) : "{}");

    It does not throw a warning in case there’s no request body, and simply fallback to an empty object instead of null.

  2. Binyamin

    @David, you might want to merge $_POST and 'php://input'

    $_POST = array_merge($_POST, (array) json_decode(file_get_contents('php://input')));
  3. Jose Maria Ferri Azorin

    You say “It makes sense that the JSON isn’t handled via normal $_POST…” but I can’t find any sense since I’m using jQuery AJAX or XMLHttpResponse calls (POST) from many years ago, parsing parameters as json or plain text and parameters, in server, are where I expect they are: $_POST array… for me, using file_get_contents('php://input') is a non-logic behaviour

Wrap your code in <pre class="{language}"></pre> tags, link to a GitHub gist, JSFiddle fiddle, or CodePen pen to embed!