I just released a twig extension for https://github.com/sebastianbergmann/money

The money libary contains a money represention based on the currency’s smallest unit to provide a more accurate handling. See the libary’s readme for more information.

Although the v1.x version of Money brings a Formatter the Twig extension uses its own, which is better suited and more flexible.

What it does? See this:

{{ money|money_i18n_format('de_DE') }} 1.123,45 €
{{ money|money_i18n_format('en_US') }} €1,123.45
{{ money|money_i18n_decimal('en_US') }} 1,123.45
{{ money|money_currency_symbol('en_US') }} €
{{ money|money_currency_name('en_US') }} Euro

Check the readme for more information.

As Composer appeared, installation and autoloading is a breeze nowadays.
I presume here, that you have installed your Silex project via composer.
If so, you can install the twig extensions like this:

Just go to your project folder and run:

composer require twig/extensions:~1.0

and your done with installation and autoloading.

Now to integration and service registration, this also got more easy.

Place this after you have registered the twig service:

$app['twig'] = $app->share($app->extend('twig', function($twig, $app) {
    $twig->addExtension(new Twig_Extensions_Extension_Text($app));
    return $twig;
}));

Thats it, now you can use the text filters in your twig templates:

{{ post.content|truncate(200)|raw }}

Easy…

Actually its like in PHP:

{{ 11 % 7 }}

As described here

But i guess for most use cases modulus is used to check if a number is divisible by another number.
Therefore Twig has the very conveniant divisible by test function.

{% if loop.index is divisible by(3) %}

Another modulo use case is to check odd and even rows in loops. There Twig has the built-in function cycle to help you.

{{ cycle(['odd', 'even'], i) }}

Once you know its so eeasy;)

The twig-extension repository is usually fetched by calling

$ bin/vendor install

into your project´s ./vendor directory (because it is part of the ./deps file of each symfony 2 standard edition).

After installing the required vendor files, register the namespace fallback in your autoload.php (if you use the one delivered with Symfony 2 Standard, this should already have been done for you):

use Symfony\Component\ClassLoader\UniversalClassLoader;
use Doctrine\Common\Annotations\AnnotationRegistry;

$loader = new UniversalClassLoader();
$loader->registerNamespaces(array(
    'Symfony'          => array(__DIR__.'/../vendor/symfony/src', __DIR__.'/../vendor/bundles'),
    // ...
));

$loader->registerPrefixes(array(
    'Twig_Extensions_' => __DIR__.'/../vendor/twig-extensions/lib',
    'Twig_'            => __DIR__.'/../vendor/twig/lib',
));

Remember that twig extensions are always registered as tagged services, but it is not always desirable to register a twig extension like e.g. the Debug-Extension as a regular service globally. We could do so by adding the service definition to the services.xml-file in one of our bundles. But due to the special purpose of the debug extension, we will choose a different, more “project-wide-configuration”-way.

Luckily, Symfony provides means to dynamically load services “on demand” and depending on the current environment.

Add the following lines to your app/config/config_dev.yml:

services:
    debug.twig.extension:
        class: Twig_Extensions_Extension_Debug
        tags: [{ name: 'twig.extension' }]

The “services”-configuration option may be utilized to register any class as a DIC managed service, for each project and independent from your bundle configuration (But remember that “regular” service definition configuration should usually happen in your bundle´s configuration files, otherwise you will not able to distribute your bundles because of missing or broken dependencies).

For twig extensions that should only be loaded for special purposes (like our DEBUG-function which is only needed in development environments), config_dev.yml is the perfect place to register them.

Note the “tags”-configuration which marks the service as a twig extension. Now, let´s create a demo twig-template and try the {% debug %} function:

{% extends "NerdpressDemoBundle::layout.html.twig" %}
{% debug %}

That will do. Open the page in your favorite webbrower (after defining a route, a controller and other stuff i won´t mention here) and admire the debug output. Note that the output will be much more nicer if you have had installed a native php debug extension like e.g. XDebug.

    Symfony\Component\Security\Core\SecurityContext|void         getSecurity()
    Symfony\Component\Security\Core\User\(Advanced)UserInterface getUser()
    Symfony\Component\HttpFoundation\Request|void                getRequest()
    Symfony\Component\HttpFoundation\Session|void                getSession()
    string                                                       getEnvironment()
    bool                                                         getDebug()

In Twig liegt der Container im “app”-Namespace, “Übersetzt” nach Twig heißt das ganze also:

    app.security
    app.user
    app.request
    app.session
    app.environment
    app.debug

Viel Spaß beim Templates-Bauen ;)

Also node.js via macports holen:

$ sudo port install nodejs

Und den node.js-eigenen Package-Manager:

$ sudo port install npm

Mit diesem installieren wir als nächsts less, und zwar “global” (via -g)-Flag (“global” bedeutet, dass das Modul unter $nodejs_lib_path/../node_modules abgelegt wird, ansonsten wird es im aktuellen Arbeitsverzeichnis unter ./node_modules installiert):

$ sudo npm install -g less

Damit haben wir alles, um unsere less CSS Stylesheets kompilieren zu können.

Als nächstes holen wir uns den Yui-Kompressor, diesen habe ich mir einfach aus dem Netz gezogen und unter app/java/yuicompressor-2.4.6.jar abgelegt (Die Binary findet ihr unter http://developer.yahoo.com/yui/compressor/).

Nun die Konfiguration:

app/config.yml:

# Assetic Configuration
assetic:
    debug:          %kernel.debug%
    use_controller: false
    filters:
        cssrewrite: ~
        less:
          node: /opt/local/bin/node
          node_paths: [/opt/local/lib/node, /opt/local/lib/node_modules]
        yui_css:
          jar: %kernel.root_dir%/java/yuicompressor-2.4.6.jar

Zu beachten sind die “node_paths”. Der node.js-Modulpfad muss explizit angegeben werden, sonst kann node.js die require()-Statements nicht auflösen (das sind sozusagen die node.js-“Classpaths”). /opt/local/lib/node zeigt auf Core-Module, in /opt/local/lib/node_modules liegt unser less.

Um den Yui-Kompressor zu aktivieren, reicht der simple Pfad zur .jar-Datei.

Nun müssen wir nur noch unser Twig-Layout anpassen:

src/Nerdpress/DemoBundle/Resources/views/layout.html.twig:

<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
        {% stylesheets
                '@NerdpressDemoBundle/Resources/public/css/main.css'
                '@NerdpressDemoBundle/Resources/public/css/layout.css'
        	filter='less,?yui_css'
                combine=true
        %}
          <link rel="stylesheet" href="{{ asset_url }}" type="text/css" media="all" />
        {% endstylesheets %}

Das “?” vor dem Filter “yui_css” bedingt, dass die CSS-Compression nur angeschaltet wird, wenn der Debug-Parameter auf false steht. “Combine” bedeutet, dass alle CSS-Dateien in einer einzigen, großen Datei zusammengefügt werden, und “less” bedeutet letztlich, dass alle CSS-Dateien mittels less CSS precompiled werden.

That´s it. Die Seite im Browser öffnen und das Ergebnis bewundern. Viel Spaß! Symfony ist schon was feines…