README

A Twig 3 extension that gives templates a create_attribute() function for collecting, sanitizing, and rendering HTML attributes — backed by a vendored, maintained port of Drupal's Attribute class.

The package ships its own port (under Drupal\Component\Attribute) rather than depending on Drupal core. The vendored sources are refreshed from Drupal 11.x on each release; the API matches what Drupal templates expect.

Installation

composer require parisek/twig-attribute

Requires PHP ^8.3 and Twig ^3.0. No Drupal dependencies.

Usage

Plain PHP:

$twig = new \Twig\Environment($loader);
$twig->addExtension(new \Parisek\Twig\AttributeExtension());

Symfony service:

services:
  Parisek\Twig\AttributeExtension:
    tags: [{ name: twig.extension }]

In templates

{% set my_attribute = create_attribute() %}
{% set my_classes = [
  'kittens',
  'llamas',
  isKitten ? 'cats' : 'dogs',
] %}
<div{{ my_attribute.addClass(my_classes).setAttribute('id', 'myUniqueId') }}>
  {{ content }}
</div>

<div{{ create_attribute({'class': ['region', 'region--header']}) }}>
  {{ content }}
</div>

The full API (class methods, escape semantics, without filter behavior) mirrors Drupal's Attribute class.

Upgrading from 1.5.x to 1.6.0

Action required: none for the vast majority of consumers. Run composer update parisek/twig-attribute.

What changes under the hood:

• The vendored Drupal\Component\Attribute\* classes are refreshed from Drupal 11.x core. Existing methods (addClass, setAttribute, removeAttribute, hasClass, merge, toArray, __toString, iterator support) keep their signatures and render output.
• New methods become available — your existing templates ignore them unless you opt in:
  • hasAttribute(string $name): bool — check existence without throwing.
  • removeClass(...$classes): static — symmetric counterpart of addClass.
  • getClass(): AttributeArray — read the class collection.
  • jsonSerialize(): string — JSON encoding support (returns the rendered attribute string).
  • __clone() — deep-clone correctness.
• The package now ships its own test suite (tests/AttributeTest.php, 18 methods, pure PHPUnit). Run vendor/bin/phpunit to verify the install if you want extra confidence.
• Composer constraints tightened to Twig 3+ and PHP ^8.3. Both were already required transitively by drupal/core-utility ^10.0 || ^11.0 in 1.5.x, so this change doesn't shrink the real install matrix.
• Both drupal/core-render and drupal/core-utility are no longer required by this package. Html::escape() is inlined as a 5-LOC private helper. NestedArray::mergeDeep and PlainTextOutput::renderFromHtml are inlined as minimal Parisek\Twig\Internal\* shims.

Edge cases that may need action

• You were reaching Drupal\Component\Render\… or Drupal\Component\Utility\… classes through this package's transitive install. Unusual, but possible if you wrote framework-level code on top of the Attribute classes. Fix: add the relevant drupal/core-* package to your own composer.json require. This is the correct long-term shape regardless — relying on transitive availability is fragile.
• You're on PHP < 8.3 or Twig 2. You couldn't actually install 1.5.x cleanly against modern Drupal 10/11 either, so this is more about cleaning up your constraints. Bump PHP/Twig in your own project, or pin parisek/twig-attribute to 1.5.* to stay on the previous floor.

Direct PHP usage

If your code does new \Drupal\Component\Attribute\AttributeCollection(...) in PHP (instead of using create_attribute() from Twig), the refresh adds methods but doesn't remove any. Your existing calls keep working in 1.6.0.

Development

composer install
vendor/bin/phpunit              # 41 tests
vendor/bin/phpstan analyse      # level 5

Source-of-truth for the vendored Drupal port is Drupal 11.x core at git.drupalcode.org/project/drupal/-/tree/11.x/core/lib/Drupal/Core/Template. When the upstream changes meaningfully, copy the relevant files into .upstream/ (gitignored scratch dir) and re-port. See docs/refresh-decisions.md for the rationale behind the inline shims that let this package drop drupal/core-render and drupal/core-utility.

Use cases

• Drupal — Pattern Lab
• WordPress — Timber
• Pimcore — Templates
• parisek/styleguide — the package that drove the 1.6.0 refresh.