Handling AngularJs POST requests with a Silex Backend


This days I working a lot with AngularJs applications (who doesn’t?). Normally my backend is a Silex application. It’s pretty straightforward to build a REST api with Silex. But when we play with an AngularJs client we need to face with a a problem. POST requests “doesn’t” work. That’s not 100% true. They work, indeed, but they speak different languages.

Silex assumes our POST requests are encoded as application/x-www-form-urlencoded, but angular encodes POST requests as application/json. That’s not a problem. It isn’t mandatory to use one encoder or another.

For example

name: Gonzalo
surname: Ayuso

If we use application/x-www-form-urlencoded, it’s encoded to:
name=Gonzalo&surname=Ayuso

And if we use application/json, it’s encoded to:
{ "name" : "Gonzalo", "surname" : "Ayuso" }

It’s the same but it isn’t.

Imagine this Silex example.

use Silex\Application;
use Symfony\Component\HttpFoundation\Request;

$app = new Application();

$app->post("/post", function (Application $app, Request $request) {
    return $app->json([
        'status' => true,
        'name'   => $request->get('name')
    ]);
});

This example works with application/x-www-form-urlencoded but it doesn’t work with application/json. We cannot use Symfony\Component\HttpFoundation\Request parameter’s bag as usual. We can get the raw request body with:

$request->getContent();

Our content in a application/json encoded Request is a JSON, so we can use json_decode to access to those parameters.

If we read the Silex documentation we can see how to handle those requests

http://silex.sensiolabs.org/doc/cookbook/json_request_body.html

In this post we’re going to enclose this code within a service provider. OK, that’s not really a service provider (it doesn’t provide any service). It just change the request (when we get application/json) without copy and paste the same code within each project.

use Silex\Application;
use G\AngularPostRequestServiceProvider;
use Symfony\Component\HttpFoundation\Request;

$app = new Application();
$app->register(new AngularPostRequestServiceProvider());

$app->post("/post", function (Application $app, Request $request) {
    return $app->json([
        'status' => true,
        'name'   => $request->get('name')
    ]);
});

The service provider is very simple

namespace G;

use Silex\Application;
use Symfony\Component\HttpFoundation\Request;
use Pimple\ServiceProviderInterface;
use Pimple\Container;

class AngularPostRequestServiceProvider implements ServiceProviderInterface
{
    public function register(Container $app)
    {
        $app->before(function (Request $request) {
            if ($this->isRequestTransformable($request)) {
                $transformedRequest = $this->transformContent($request->getContent());
                $request->request->replace($transformedRequest);
            }
        });
    }

    public function boot(Application $app)
    {
    }

    private function transformContent($content)
    {
        return json_decode($content, true);
    }

    private function isRequestTransformable(Request $request)
    {
        return 0 === strpos($request->headers->get('Content-Type'), 'application/json');
    }
}

You can see the whole code in my github account and also in packagist

About Gonzalo Ayuso

Web Architect. PHP, Python, Node, Angular, ionic, PostgreSQL, Linux, ... Always learning.

Posted on February 2, 2015, in AngularJS, silex, Technology and tagged , , , . Bookmark the permalink. 3 Comments.

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