JoHTVS JoHTVS -4 years ago 330
Twig Question

Adding a Twig Extension class makes compilation errors

I'm using Silex (1.3) for a project and I wanted to add a Twig extension that complies with the Twig_Extension interface :

namespace LizardCMS\Twig\Extension;

class DateExtension extends Twig_Extension {

public function getFilters() {
array(new \Twig_SimpleFilter($this, 'relative'));

public function relative($date) {
$date = new \DateTime($date);
$difference = time() - $date->getTimestamp();
$periods = array("seconde", "minute", "heure", "jour", "semaine", "mois", "an", "decade");
$lengths = array("60", "60", "24", "7", "4.35", "12", "10");

for ($j = 0; $difference >= $lengths[$j] and $j < 7; $j++)
$difference /= $lengths[$j];
$difference = round($difference);
if ($difference != 1) {
$periods[$j].= "s";
$text = "il y $difference $periods[$j]";
return $text;

public function timestamp($date) {
$datetime = new \DateTime($date);
return "il y a ".$datetime->getTimestamp()." secondes";

public function daymonthyear($date, $withSlashes = true) {
$datetime = new \DateTime($date);
$separator = ($withSlashes ? "/" : "-");
return "le ".$datetime->format("d".$separator."m".$separator."Y");

public function chosenDateTimeFormat($app, $date) {
$format = strtolower($app['controller.configuration']->findAll()->getDateTimeFormat());
if(in_array($format, array("relative", "timestamp", "daymonthyear"))) {
return $this->$format($date);

public function getName() {
return 'Date';


After adding it :

$app["twig"] = $app->share($app->extend("twig", function (\Twig_Environment $twig, Silex\Application $app) {
$twig->addExtension(new LizardCMS\Twig\Extension\DateExtension());
return $twig;

...this cute error appears :

Twig_Error_Syntax in Environment.php line 601: An exception has been thrown during the compilation of a template ("Warning: Invalid argument supplied for foreach()") in "index.html.twig".

But there's no problem in my foreach because if I remove my Twig extension, the template loads without any error.

Adding filters and functions in the bootstrap file is really annoying to me.

Any help would be appreciated!

Answer Source

The solution is quite simple. You forgot to return your array of filters, adjust your code to :

public function getFilters() {
   return array(new \Twig_SimpleFilter($this, 'relative'));
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