Add Custom Twig Functions

Overview

Let us consider, for instance, you want to call a PHP script from the twig template during the theme development to create a MD5-hash. In such a case, you can create your own twig functions. For this example, pass a string to the TwigFunction and return a MD5-Hash.

INFO

It is not recommended to use twig functions in order to retrieve data from the database. In such a case, DataResolver could come in handy.

Prerequisites

In order to create your own twig function for your plugin, you first need a plugin as base. Therefore, you can refer to the Plugin Base Guide.

Creating twig function

In the following sections, we will create and expand all necessary files for the twig function to work. There are two such files:

• PHP file with the twig functions itself and
• Services.xml

Creating the twig function

For clarity, create a folder named Twig within the src folder. Then create a new php file with desired file name within the Twig folder. Refer to the below example :

// <plugin root>/src/Twig/SwagCreateMd5Hash.php
<?php declare(strict_types=1);

namespace SwagBasicExample\Twig;

use Shopware\Core\Framework\Context;
use Twig\Extension\AbstractExtension;
use Twig\TwigFunction;

class SwagCreateMd5Hash extends AbstractExtension
{
    public function getFunctions()
    {
        return [
            new TwigFunction('createMd5Hash', [$this, 'createMd5Hash']),
        ];
    }

    public function createMd5Hash(string $str)
    {
        return md5($str);
    }
}

Of course, you can do everything in the createMd5Hash function that PHP can do, but the service.xml handles registration of the service in the DI container.

// <plugin root>/src/Resources/config/services.xml
...
    <services>
        <service id="SwagBasicExample\Twig\SwagCreateMd5Hash" public="true">
            <tag name="twig.extension"/> <!--Required-->
        </service>
    </services>
...

Once done, you can access this TwigFunction within your plugin.

Use twig function in template

The created function is now available in all your templates. You can call it like each other function.

{% sw_extends '@Storefront/storefront/layout/header/header.html.twig' %}

{% set md5Hash = createMd5Hash('Shopware is awesome') %}

{% block layout_header_logo %}
    {{ parent() }}

    {{ md5Hash }}
{% endblock %}