Added truncate() Twig function.

src/TwigExtension.php

@@ -2,6 +2,7 @@
 
 namespace Drupal\twig_tweak;
 
+use Drupal\Component\Utility\Unicode;
 use Drupal\Component\Uuid\Uuid;
 use Drupal\Core\Block\BlockPluginInterface;
 use Drupal\Core\Block\TitleBlockPluginInterface;
@@ -60,6 +61,7 @@ class TwigExtension extends \Twig_Extension {
       new \Twig_SimpleFilter('image_style', [$this, 'imageStyle']),
       new \Twig_SimpleFilter('transliterate', [$this, 'transliterate']),
       new \Twig_SimpleFilter('check_markup', [$this, 'checkMarkup']),
+      new \Twig_SimpleFilter('truncate', [$this, 'truncate']),
       new \Twig_SimpleFilter('view', [$this, 'view']),
     ];
     // PHP filter should be enabled in settings.php file.
@@ -621,6 +623,30 @@ class TwigExtension extends \Twig_Extension {
     return check_markup($text, $format_id, $langcode, $filter_types_to_skip);
   }
 
+  /**
+   * Truncates a UTF-8-encoded string safely to a number of characters.
+   *
+   * @param string $string
+   *   The string to truncate.
+   * @param int $max_length
+   *   An upper limit on the returned string length, including trailing ellipsis
+   *   if $add_ellipsis is TRUE.
+   * @param bool $wordsafe
+   *   (Optional) If TRUE, attempt to truncate on a word boundary.
+   * @param bool $add_ellipsis
+   *   (Optional) If TRUE, add '...' to the end of the truncated string.
+   * @param int $min_wordsafe_length
+   *   (Optional) If TRUE, the minimum acceptable length for truncation.
+   *
+   * @return string
+   *   The truncated string.
+   *
+   * @see Unicode::truncate()
+   */
+  public function truncate($string, $max_length, $wordsafe = FALSE, $add_ellipsis = FALSE, $min_wordsafe_length = 1) {
+    return Unicode::truncate($string, $max_length, $wordsafe, $add_ellipsis, $min_wordsafe_length);
+  }
+
   /**
    * Returns a render array for entity, field list or field item.
    *

tests/src/Functional/TwigTweakTest.php

@@ -227,6 +227,10 @@ class TwigTweakTest extends BrowserTestBase {
     $xpath = '//div[@class = "tt-check-markup"]';
     self::assertEquals('<b>bold</b> strong', trim($this->xpath($xpath)[0]->getHtml()));
 
+    // Test truncation.
+    $xpath = '//div[@class = "tt-truncate" and text() = "Hello…"]';
+    $this->assertByXpath($xpath);
+
     // Test node view.
     $xpath = '//div[@class = "tt-node-view"]/article[contains(@class, "node--view-mode-default")]/h2[a/span[text() = "Beta"]]';
     $xpath .= '/following-sibling::footer[//h4[text() = "Member for"]]';

tests/twig_tweak_test/templates/twig-tweak-test.html.twig

@@ -51,6 +51,7 @@
   <div class="tt-image-style">{{ 'public://images/ocean.jpg' | image_style('thumbnail') }}</div>
   <div class="tt-transliterate">{{ 'Привет!' | transliterate('ru') }}</div>
   <div class="tt-check-markup">{{ '<b>bold</b> <strong>strong</strong>' | check_markup('twig_tweak_test') }}</div>
+  <div class="tt-truncate">{{ 'Hello world!'|truncate(10, true, true) }}</div>
   <div class="tt-node-view">{{ node|view }}</div>
   <div class="tt-field-list-view">{{ node.title|view }}</div>
   <div class="tt-field-item-view">{{ node.title[0]|view }}</div>