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

  • By
    CSS @supports

    Feature detection via JavaScript is a client side best practice and for all the right reasons, but unfortunately that same functionality hasn't been available within CSS.  What we end up doing is repeating the same properties multiple times with each browser prefix.  Yuck.  Another thing we...

  • By
    Write Simple, Elegant and Maintainable Media Queries with Sass

    I spent a few months experimenting with different approaches for writing simple, elegant and maintainable media queries with Sass. Each solution had something that I really liked, but I couldn't find one that covered everything I needed to do, so I ventured into creating my...

Incredible Demos

  • By
    jQuery Wookmark

    The first thing that hits you when you visit Pinterest is "Whoa, the columns are the same width and the photos are cut to fit just the way they should."  Basic web users probably think nothing of it but as a developer, I can appreciate the...

  • By
    WordPress-Style Comment Controls Using MooTools or jQuery

    WordPress has a nice little effect on the Admin Dashboard where it shows and hides the comment control links when you mouseover and mouseout of the record's container. Here's how to achieve that effect using MooTools or jQuery. The XHTML Notice that we place the links into...

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!