class TwigNodeVisitorCheckDeprecations

Provides a Node Visitor to trigger errors if deprecated variables are used.

Every use of a named variable is tracked, and the used variable names are passed to TwigExtension::checkDeprecations at runtime for comparison against those in the 'deprecated' array in the template context.

Hierarchy

Expanded class hierarchy of TwigNodeVisitorCheckDeprecations

See also

\Drupal\Core\Template\TwigNodeCheckDeprecations

File

View on git.drupalcode.org

core/lib/Drupal/Core/Template/TwigNodeVisitorCheckDeprecations.php, line 21

Namespace

Drupal\Core\Template
View source 
class TwigNodeVisitorCheckDeprecations implements NodeVisitorInterface {
  
  /**
   * The named variables used in the template from the context.
   */
  protected array $usedNames = [];
  
  /**
   * The named variables set within the template.
   */
  protected array $assignedNames = [];
  
  /**
   * {@inheritdoc}
   */
  public function enterNode(Node $node, Environment $env) : Node {
    if ($node instanceof ModuleNode) {
      $this->usedNames = [];
      $this->assignedNames = [];
    }
    elseif ($node instanceof AssignNameExpression) {
      // Setting a variable makes subsequent usage is safe.
      $this->assignedNames[$node->getAttribute('name')] = $node->getAttribute('name');
    }
    elseif ($node instanceof NameExpression) {
      // Track each usage of a variable, unless set within the template.
      $name = $node->getAttribute('name');
      if (!in_array($name, $this->assignedNames)) {
        $this->usedNames[$name] = $name;
      }
    }
    return $node;
  }
  
  /**
   * {@inheritdoc}
   */
  public function leaveNode(Node $node, Environment $env) : ?Node {
    // At the end of the template, check the used variables are not deprecated.
    if ($node instanceof ModuleNode) {
      if (!empty($this->usedNames)) {
        $checkNode = new Node([
          new TwigNodeCheckDeprecations($this->usedNames),
          $node->getNode('display_end'),
        ]);
        $node->setNode('display_end', $checkNode);
      }
    }
    return $node;
  }
  
  /**
   * {@inheritdoc}
   */
  public function getPriority() : int {
    // Just above the Optimizer, which is the normal last one.
    return 256;
  }

}

Members

Title Modifiers Object type Summary
TwigNodeVisitorCheckDeprecations::$assignedNames protected property The named variables set within the template.
TwigNodeVisitorCheckDeprecations::$usedNames protected property The named variables used in the template from the context.
TwigNodeVisitorCheckDeprecations::enterNode public function
TwigNodeVisitorCheckDeprecations::getPriority public function
TwigNodeVisitorCheckDeprecations::leaveNode public function

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