How to Write a custom Twig Extension
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How to Write a custom Twig Extension
If you need to create custom Twig functions, filters, tests or more, you'll need to create a Twig extension. You can read more about Twig Extensions in the Twig documentation.
Create the Extension Class
Suppose you want to create a new filter called price that formats a number into
money:
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{{ product.price|price }}
{# pass in the 3 optional arguments #}
{{ product.price|price(2, ',', '.') }}Create a class that extends \Twig_Extension and fill in the logic:
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// src/AppBundle/Twig/AppExtension.php
namespace AppBundle\Twig;
class AppExtension extends \Twig_Extension
{
public function getFilters()
{
return array(
new \Twig_SimpleFilter('price', array($this, 'priceFilter')),
);
}
public function priceFilter($number, $decimals = 0, $decPoint = '.', $thousandsSep = ',')
{
$price = number_format($number, $decimals, $decPoint, $thousandsSep);
$price = '$'.$price;
return $price;
}
}Note
Prior to Twig 1.26, your extension had to define an additional getName()
method that returned a string with the extension's internal name (e.g.
app.my_extension). When your extension needs to be compatible with Twig
versions before 1.26, include this method which is omitted in the example
above.
Tip
Along with custom filters, you can also add custom functions and register global variables.
Register an Extension as a Service
Next, register your class as a service and tag it with twig.extension. If you're
using the default services.yml configuration,
you're done! Symfony will automatically know about your new service and add the tag.
You can now start using your filter in any Twig template.
