[support] AssetReference HELP !

[quazardous]

I'm using Silex with twig and assetic.

Can somebody tell me how to add an asset reference for something like

        {% javascripts '@plugin' filter='yui_js' output="js/plugin" %}
            <script src="{{ asset(asset_url) }}"></script>
        {% endjavascripts %}

I've tried to follow the doc but I was never able to actually render the twig template...

I've added a couple of code lines to dump it via a command but that's all.

That's the doc:

use Assetic\Asset\AssetCollection;
use Assetic\Asset\AssetReference;
use Assetic\Asset\FileAsset;

$am->set('my_plugin', new AssetCollection(array(
    new AssetReference($am, 'jquery'),
    new FileAsset('/path/to/jquery.plugin.js'),
)));

But in fact I don't understand why I have to declare the assets since there is a Twig formulae loader:

use Assetic\AssetWriter;
use Assetic\Extension\Twig\TwigFormulaLoader;
use Assetic\Extension\Twig\TwigResource;
use Assetic\Factory\LazyAssetManager;

$am = new LazyAssetManager($factory);

// enable loading assets from twig templates
$am->setLoader('twig', new TwigFormulaLoader($twig));

// loop through all your templates
foreach ($templates as $template) {
    $resource = new TwigResource($twigLoader, $template);
    $am->addResource($resource, 'twig');
}

$writer = new AssetWriter('/path/to/web');
$writer->writeManagerAssets($am);

I'm working on https://github.com/quazardous/silex-pack