Issue #3301373 by hawkeye.twolf, lauriii, alexpott, mherchel: Create twig |add_suggestion filter (75f7ef8b) · Commits · project / drupal

core/lib/Drupal/Core/Template/TwigExtension.php

+59 −0

Changes for core/lib/Drupal/Core/Template/TwigExtension.php: 59 added lines, 0 removed lines.
Original line number	Diff line number	Diff line
		@@ -143,6 +143,8 @@ public function getFilters() {
		// This filter will render a renderable array to use the string results.
		new TwigFilter('render', [$this, 'renderVar']),
		new TwigFilter('format_date', [$this->dateFormatter, 'format']),
		// Add new theme hook suggestions directly from a Twig template.
		new TwigFilter('add_suggestion', [$this, 'suggestThemeHook']),
		];
		}

		@@ -653,4 +655,61 @@ public function withoutFilter($element) {
		return $filtered_element;
		}

		/**
		* Adds a theme suggestion to the element.
		*
		* @param array\|null $element
		* A theme element render array.
		* @param string\|\Stringable $suggestion
		* The theme suggestion part to append to the existing theme hook(s).
		*
		* @return array\|null
		* The element with the full theme suggestion added as the highest priority.
		*/
		public function suggestThemeHook(?array $element, string\|\Stringable $suggestion): ?array {
		// Make sure we have a valid theme element render array.
		if (empty($element['#theme'])) {
		// Throw assertion for render arrays that contain more than just metadata
		// (e.g., don't assert on empty field content).
		assert(array_diff_key($element ?? [], [
		'#cache' => TRUE,
		'#weight' => TRUE,
		'#attached' => TRUE,
		]) === [], 'Invalid target for the "\|add_suggestion" Twig filter; element does not have a "#theme" key.');
		return $element;
		}

		// Replace dashes with underscores to support suggestions that match the
		// target template name rather than the underlying theme hook.
		$suggestion = str_replace('-', '_', $suggestion);

		// Transform the theme hook to a format that supports multiple suggestions.
		if (!is_iterable($element['#theme'])) {
		$element['#theme'] = [$element['#theme']];
		}

		// Add _new_ suggestions for each existing theme hook. Simply modifying the
		// existing items (appending to each theme hook instead of adding new ones)
		// would cause the original hooks to be unavailable as fallbacks.
		//
		// Start with the lowest priority theme hook.
		foreach (array_reverse($element['#theme']) as $theme_hook) {
		// Add new suggestions to the front (highest priority).
		array_unshift($element['#theme'], $theme_hook . '__' . $suggestion);
		}

		// Reset the "#printed" flag to make sure the content gets rendered with the
		// new suggestion in place.
		unset($element['#printed']);

		// Add a cache key to prevent using render cache from before the suggestion
		// was added. If there are no cache keys already set, don't add one, as that
		// would enable caching on this element where there wasn't any before.
		if (isset($element['#cache']['keys'])) {
		$element['#cache']['keys'][] = $suggestion;
		}

		return $element;
		}

		}

core/tests/Drupal/Tests/Core/Template/TwigExtensionTest.php

+118 −0

Changes for core/tests/Drupal/Tests/Core/Template/TwigExtensionTest.php: 118 added lines, 0 removed lines.
Original line number	Diff line number	Diff line
		@@ -2,6 +2,8 @@

		namespace Drupal\Tests\Core\Template;

		// cspell:ignore mila

		use Drupal\Core\File\FileUrlGeneratorInterface;
		use Drupal\Core\GeneratedLink;
		use Drupal\Core\Render\RenderableInterface;
		@@ -424,6 +426,122 @@ public function testLinkWithOverriddenAttributes() {
		$this->assertEquals(['foo', 'bar'], $build['#url']->getOption('attributes')['class']);
		}

		/**
		* Tests Twig 'add_suggestion' filter.
		*
		* @covers ::suggestThemeHook
		* @dataProvider providerTestTwigAddSuggestionFilter
		*/
		public function testTwigAddSuggestionFilter($original_render_array, $suggestion, $expected_render_array) {
		$processed_render_array = $this->systemUnderTest->suggestThemeHook($original_render_array, $suggestion);
		$this->assertEquals($expected_render_array, $processed_render_array);
		}

		/**
		* A data provider for ::testTwigAddSuggestionFilter().
		*
		* @return \Iterator
		*/
		public function providerTestTwigAddSuggestionFilter(): \Iterator {
		yield 'suggestion should be added' => [
		[
		'#theme' => 'kitten',
		'#name' => 'Mila',
		],
		'cute',
		[
		'#theme' => [
		'kitten__cute',
		'kitten',
		],
		'#name' => 'Mila',
		],
		];

		yield 'suggestion should extend existing suggestions' => [
		[
		'#theme' => 'kitten__stripy',
		'#name' => 'Mila',
		],
		'cute',
		[
		'#theme' => [
		'kitten__stripy__cute',
		'kitten__stripy',
		],
		'#name' => 'Mila',
		],
		];

		yield 'suggestion should have highest priority' => [
		[
		'#theme' => [
		'kitten__stripy',
		'kitten',
		],
		'#name' => 'Mila',
		],
		'cute',
		[
		'#theme' => [
		'kitten__stripy__cute',
		'kitten__cute',
		'kitten__stripy',
		'kitten',
		],
		'#name' => 'Mila',
		],
		];

		yield '#printed should be removed after suggestion was added' => [
		[
		'#theme' => 'kitten',
		'#name' => 'Mila',
		'#printed' => TRUE,
		],
		'cute',
		[
		'#theme' => [
		'kitten__cute',
		'kitten',
		],
		'#name' => 'Mila',
		],
		];

		yield 'cache key should be added' => [
		[
		'#theme' => 'kitten',
		'#name' => 'Mila',
		'#cache' => [
		'keys' => [
		'kitten',
		],
		],
		],
		'cute',
		[
		'#theme' => [
		'kitten__cute',
		'kitten',
		],
		'#name' => 'Mila',
		'#cache' => [
		'keys' => [
		'kitten',
		'cute',
		],
		],
		],
		];

		yield 'null/missing content should be ignored' => [
		NULL,
		'cute',
		NULL,
		];
		}

		}

		class TwigExtensionTestString {