15.08.11 - Extending Twig in Symfony 2, add custom functions
How to add functions to Twig in Symfony 2
Sometimes we need to add some custom functions to the view. In Symfony 1 we have the helpers, in Symfony 2 we must extend Twig in order to add it.
At first, we have to connect our future Twig extension to the Dependency Injection Container in our Bundle. If we don't got any config file we have to create it.
At this point we have to configure what kind of service we will offer, the parameters that it will require and how is going to be connected to the kernel (file Test/MyBundle/Resources/config/twig.xml):
Once done, the last step is to extend Twig with an Extension. In this case we will add a simple function that transforms a string into a Unix timpestamp:
Thats all! To use it under your templates you only have to enter:
At first, we have to connect our future Twig extension to the Dependency Injection Container in our Bundle. If we don't got any config file we have to create it.
<?php
# Test/MyBundle/DependencyInjection/MyBundleExtension.php
namespace Test\MyBundle\DependencyInjection;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\DependencyInjection\Loader\XmlFileLoader;
use Symfony\Component\HttpKernel\DependencyInjection\Extension;
use Symfony\Component\Config\FileLocator;
class TestMyBundleExtension extends Extension
{
public function load(array $configs, ContainerBuilder $container)
{
$loader = new XmlFileLoader($container, new FileLocator(__DIR__.'/../Resources/config'));
$loader->load('twig.xml');
}
public function getAlias()
{
return 'test_my_bundle';
}
}
# Test/MyBundle/DependencyInjection/MyBundleExtension.php
namespace Test\MyBundle\DependencyInjection;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\DependencyInjection\Loader\XmlFileLoader;
use Symfony\Component\HttpKernel\DependencyInjection\Extension;
use Symfony\Component\Config\FileLocator;
class TestMyBundleExtension extends Extension
{
public function load(array $configs, ContainerBuilder $container)
{
$loader = new XmlFileLoader($container, new FileLocator(__DIR__.'/../Resources/config'));
$loader->load('twig.xml');
}
public function getAlias()
{
return 'test_my_bundle';
}
}
<?xml version="1.0" ?>
<container xmlns="http://symfony.com/schema/dic/services"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd">
<services>
<service id="twig.extension.ka.blog" class="Test\MyBundle\Twig\Extension\BlogExtension" public="false">
<tag name="twig.extension" />
</service>
</services>
</container>
<container xmlns="http://symfony.com/schema/dic/services"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd">
<services>
<service id="twig.extension.ka.blog" class="Test\MyBundle\Twig\Extension\BlogExtension" public="false">
<tag name="twig.extension" />
</service>
</services>
</container>
<?php
# Test/MyBundle/Twig/Extension/MyBundleExtension.php
namespace Test\MyBundle\Twig\Extension;
use Symfony\Component\HttpKernel\KernelInterface;
class MyBundleExtension extends \Twig_Extension
{
public function __construct()
{
}
/**
* {@inheritdoc}
*/
public function getFunctions()
{
return array(
'totime' => new \Twig_Function_Method($this, 'toTime')
);
}
/**
* Converts a string to time
*
* @param string $string
* @return int
*/
public function toTime ($string)
{
return strtotime($string);
}
/**
* Returns the name of the extension.
*
* @return string The extension name
*/
public function getName()
{
return 'my_bundle';
}
}
# Test/MyBundle/Twig/Extension/MyBundleExtension.php
namespace Test\MyBundle\Twig\Extension;
use Symfony\Component\HttpKernel\KernelInterface;
class MyBundleExtension extends \Twig_Extension
{
public function __construct()
{
}
/**
* {@inheritdoc}
*/
public function getFunctions()
{
return array(
'totime' => new \Twig_Function_Method($this, 'toTime')
);
}
/**
* Converts a string to time
*
* @param string $string
* @return int
*/
public function toTime ($string)
{
return strtotime($string);
}
/**
* Returns the name of the extension.
*
* @return string The extension name
*/
public function getName()
{
return 'my_bundle';
}
}
{{ totime(strtime) }}
Great article, thanks!
While it may be a nice idea to use Symfony's dependency injection mechanism, I found this to be a lot easier: namespace Bundle\MyBundle; use Bundle\MyBundle\Twig\Extension\MyExtension; class MyBundle extends Bundle { public function boot() { $extension = new MyExtension(); $this->get('twig')->addExtension($extension); } } Two lines of code should be good enough for anybody. Why so complicated if there is an easy way that just works?
Hello dude! I’ve just stopped by to say thanks for this cool site! Keep going that way.
Hi man! Nice resource! I really liked being here.
@Tom - doing it your way removes the ability to be able to override the extension class if eg I wanted to use your bundle and drop in a replacement. Using the provided DI mechanisms removes this restriction.
Thx man! This was missing from symdony docs :)