class TwigNodeTrans in Drupal 10

A class that defines the Twig 'trans' tag for Drupal.

This Twig extension was originally based on Twig i18n extension. It has been severely modified to work properly with the complexities of the Drupal translation system.

Hierarchy

• class \Drupal\Core\Template\TwigNodeTrans extends \Twig\Node\Node

See also

https://twig-extensions.readthedocs.io/en/latest/i18n.html

https://github.com/fabpot/Twig-extensions

1 file declares its use of TwigNodeTrans

HelpTestTwigNodeVisitor.php in core/modules/help_topics/tests/modules/help_topics_twig_tester/src/HelpTestTwigNodeVisitor.php

File

core/lib/Drupal/Core/Template/TwigNodeTrans.php, line 28

Namespace

Drupal\Core\Template

class TwigNodeTrans extends Node {

  /**
   * {@inheritdoc}
   */
  public function __construct(Node $body, Node $plural = NULL, AbstractExpression $count = NULL, AbstractExpression $options = NULL, $lineno, $tag = NULL) {
    $nodes['body'] = $body;
    if ($count !== NULL) {
      $nodes['count'] = $count;
    }
    if ($plural !== NULL) {
      $nodes['plural'] = $plural;
    }
    if ($options !== NULL) {
      $nodes['options'] = $options;
    }
    parent::__construct($nodes, [], $lineno, $tag);
  }

  /**
   * {@inheritdoc}
   */
  public function compile(Compiler $compiler) {
    $compiler
      ->addDebugInfo($this);
    [
      $singular,
      $tokens,
    ] = $this
      ->compileString($this
      ->getNode('body'));
    $plural = NULL;
    if ($this
      ->hasNode('plural')) {
      [
        $plural,
        $pluralTokens,
      ] = $this
        ->compileString($this
        ->getNode('plural'));
      $tokens = array_merge($tokens, $pluralTokens);
    }

    // Start writing with the function to be called.
    $compiler
      ->write('echo ' . (empty($plural) ? 't' : '\\Drupal::translation()->formatPlural') . '(');

    // Move the count to the beginning of the parameters list.
    if (!empty($plural)) {
      $compiler
        ->raw('abs(')
        ->subcompile($this
        ->getNode('count'))
        ->raw('), ');
    }

    // Write the singular text parameter.
    $compiler
      ->subcompile($singular);

    // Write the plural text parameter, if necessary.
    if (!empty($plural)) {
      $compiler
        ->raw(', ')
        ->subcompile($plural);
    }

    // Write any tokens found as an associative array parameter, otherwise just
    // leave as an empty array.
    $compiler
      ->raw(', array(');
    foreach ($tokens as $token) {
      $compiler
        ->string($token
        ->getAttribute('placeholder'))
        ->raw(' => ')
        ->subcompile($token)
        ->raw(', ');
    }
    $compiler
      ->raw(')');

    // Write any options passed.
    if ($this
      ->hasNode('options')) {
      $compiler
        ->raw(', ')
        ->subcompile($this
        ->getNode('options'));
    }

    // Write function closure.
    $compiler
      ->raw(')');

    // @todo Add debug output, see https://www.drupal.org/node/2512672
    // End writing.
    $compiler
      ->raw(";\n");
  }

  /**
   * Extracts the text and tokens for the "trans" tag.
   *
   * @param \Twig\Node\Node $body
   *   The node to compile.
   *
   * @return array
   *   Returns an array containing the two following parameters:
   *   - string $text
   *       The extracted text.
   *   - array $tokens
   *       The extracted tokens as new \Twig\Node\Expression\TempNameExpression
   *       instances.
   */
  protected function compileString(Node $body) {
    if ($body instanceof NameExpression || $body instanceof ConstantExpression || $body instanceof TempNameExpression) {
      return [
        $body,
        [],
      ];
    }
    $tokens = [];
    if (count($body)) {
      $text = '';
      foreach ($body as $node) {
        if ($node instanceof PrintNode) {
          $n = $node
            ->getNode('expr');
          while ($n instanceof FilterExpression) {
            $n = $n
              ->getNode('node');
          }
          if ($n instanceof CheckToStringNode) {
            $n = $n
              ->getNode('expr');
          }
          $args = $n;

          // Support TwigExtension->renderVar() function in chain.
          if ($args instanceof FunctionExpression) {
            $args = $n
              ->getNode('arguments')
              ->getNode(0);
          }

          // Detect if a token implements one of the filters reserved for
          // modifying the prefix of a token. The default prefix used for
          // translations is "@". This escapes the printed token and makes them
          // safe for templates.
          // @see TwigExtension::getFilters()
          $argPrefix = '@';
          while ($args instanceof FilterExpression) {
            switch ($args
              ->getNode('filter')
              ->getAttribute('value')) {
              case 'placeholder':
                $argPrefix = '%';
                break;
            }
            $args = $args
              ->getNode('node');
          }
          if ($args instanceof CheckToStringNode) {
            $args = $args
              ->getNode('expr');
          }
          if ($args instanceof GetAttrExpression) {
            $argName = [];

            // Reuse the incoming expression.
            $expr = $args;

            // Assemble a valid argument name by walking through the expression.
            $argName[] = $args
              ->getNode('attribute')
              ->getAttribute('value');
            while ($args
              ->hasNode('node')) {
              $args = $args
                ->getNode('node');
              if ($args instanceof NameExpression) {
                $argName[] = $args
                  ->getAttribute('name');
              }
              else {
                $argName[] = $args
                  ->getNode('attribute')
                  ->getAttribute('value');
              }
            }
            $argName = array_reverse($argName);
            $argName = implode('.', $argName);
          }
          else {
            $argName = $n
              ->getAttribute('name');
            if (!is_null($args)) {
              $argName = $args
                ->getAttribute('name');
            }
            $expr = new NameExpression($argName, $n
              ->getTemplateLine());
          }
          $placeholder = sprintf('%s%s', $argPrefix, $argName);
          $text .= $placeholder;
          $expr
            ->setAttribute('placeholder', $placeholder);
          $tokens[] = $expr;
        }
        else {
          $text .= $node
            ->getAttribute('data');
        }
      }
    }
    elseif (!$body
      ->hasAttribute('data')) {
      throw new SyntaxError('{% trans %} tag cannot be empty');
    }
    else {
      $text = $body
        ->getAttribute('data');
    }
    return [
      new Node([
        new ConstantExpression(trim($text), $body
          ->getTemplateLine()),
      ]),
      $tokens,
    ];
  }

}