Giới thiệu Twig template trong Drupal 8 Themes

PHPTemplate is the engine that has been driving Drupal templates since 2005.

After nearly 10 years of honorable service, PHPTemplate is about to be replaced by Twig in Drupal 8.

This will be the biggest overhaul of Drupal theming in a decade.

What is Twig? How will it change Drupal themes? Read on and find out ...

What is Twig?

Twig is a template framework and is a direct replacement for PHPTemplate. 

Unlike PHPTemplate which was developed in-house by Drupal developers, Twig comes from the wider PHP world.

Twig was created created by SensioLabs, the same people who develop the Symfony2 framework. Drupal 8 is using Symfony2 to overhaul its codebase. Because Twig is natively supported by Symfony2, it was a logical choice to use for Drupal themes.

You can find the Twig website at http://twig.sensiolabs.org.

Who uses Twig?

Except for Drupal 8, it's not a very distinguished list yet:

• Pico CMS
• Craft CMS
• Bolt CMS
• Curry CMS

Without a doubt, Drupal 8 will be by far the largest platform using Twig.

Is there any Twig documentation?

• Twig has its own coding standards and documentation.
• Drupal 8 has its own standards for Twig.
• There is a http://drupaltwig.org but that is mainly of interest to people bug-shooting issues with the Drupal 8 implementation.

However, as you saw above, there aren't too many people using Twig yet. There are no books available and there's currently a shortage of online tutorials. I suspect that will start to change when Drupal 8 arrives.

How has Twig changed Drupal 8 themes?

Maybe it would be easier to answer that question in reverse ... how has Twig not changed Drupal 8 themes?

Let's compare two snippets from Bartik in Drupal 7 and 8. These snippets have an identical function.

This is Drupal 7 and the node.tpl.php file:

<?php print render($title_prefix); ?>
<?php if (!$page): ?>
<h2<?php print $title_attributes; ?>>
<a href="/<?php print $node_url; ?>"><?php print $title; ?></a>
</h2>
<?php endif; ?>
<?php print render($title_suffix); ?>

This is Drupal 8 and the new node.html.twig file:

{{ title_prefix }}
{% if not page %}
<h2{{ title_attributes }}>
<a href="/{{ node_url }}">{{ label }}</a>
</h2>
{% endif %}
{{ title_suffix }}

Why Twig in Drupal 8? #4. Redundancy

<div id="node-<?php print $node->nid; ?>" class="<?php print $classes; ?> clearfix"<?php print $attributes; ?>>

Why Twig in Drupal 8? #5. Security

Drupal 7 would often print out unsanitized data. You could even run database queries from directly inside the theme files.

Drupal 8 can automatically sanitize variables and won't permit unsafe functions to run.