twig.engine

<?php

/**
 * @file
 * Handles integration of Twig templates with the Drupal theme system.
 */
use Drupal\Core\Template\TwigReference;

/**
 * Implements hook_theme().
 */
function twig_theme($existing, $type, $theme, $path) {
  $templates = drupal_find_theme_functions($existing, array(
    $theme,
  ));
  $templates += drupal_find_theme_templates($existing, '.html.twig', $path);
  return $templates;
}

/**
 * Implements hook_extension().
 */
function twig_extension() {
  return '.html.twig';
}

/**
 * Implements hook_init().
 */
function twig_init($template) {
  $file = dirname($template->filename) . '/' . $template->name . '.theme';
  if (file_exists($file)) {
    include_once DRUPAL_ROOT . '/' . $file;
  }
}

/**
 * Renders a Twig template.
 *
 * If the Twig debug setting is enabled, HTML comments including theme() call
 * and template file name suggestions will surround the template markup.
 *
 * @param $template_file
 *   The file name of the template to render.
 * @param $variables
 *   A keyed array of variables that will appear in the output.
 *
 * @return
 *   The output generated by the template, plus any debug information.
 */
function twig_render_template($template_file, $variables) {
  $variables['_references'] = array();
  $output = array(
    'debug_prefix' => '',
    'debug_info' => '',
    'rendered_markup' => drupal_container()
      ->get('twig')
      ->loadTemplate($template_file)
      ->render($variables),
    'debug_suffix' => '',
  );
  if (settings()
    ->get('twig_debug', FALSE)) {
    $output['debug_prefix'] .= "\n\n<!-- THEME DEBUG -->";
    $output['debug_prefix'] .= "\n<!-- CALL: theme('{$variables['theme_hook_original']}') -->";
    if (!empty($variables['theme_hook_suggestions'])) {
      $extension = twig_extension();
      $current_template = basename($template_file);
      $suggestions = $variables['theme_hook_suggestions'];
      $suggestions[] = $variables['theme_hook_original'];
      foreach ($suggestions as $key => &$suggestion) {
        $template = strtr($suggestion, '_', '-') . $extension;
        $prefix = $template == $current_template ? 'x' : '*';
        $suggestion = $prefix . ' ' . $template;
      }
      $output['debug_info'] .= "\n<!-- FILE NAME SUGGESTIONS:\n   " . implode("\n   ", $suggestions) . "\n-->";
    }
    $output['debug_info'] .= "\n<!-- BEGIN OUTPUT from '{$template_file}' -->\n";
    $output['debug_suffix'] .= "\n<!-- END OUTPUT from '{$template_file}' -->\n\n";
  }
  return implode('', $output);
}

/**
 * Wrapper around render() for twig printed output.
 *
 * If an object is passed that has no __toString method an exception is thrown;
 * other objects are casted to string. However in the case that the object is an
 * instance of a Twig_Markup object it is returned directly to support auto
 * escaping.
 *
 * If an array is passed it is rendered via render() and scalar values are
 * returned directly.
 *
 * @param mixed $arg
 *   String, Object or Render Array
 *
 * @return
 *   The rendered output or an Twig_Markup object.
 *
 * @see render
 * @see TwigNodeVisitor
 */
function twig_render_var($arg) {
  if ($arg instanceof TwigReference) {
    $arg =& $arg
      ->getReference();
  }

  // Check for numeric zero.
  if ($arg === 0) {
    return 0;
  }

  // == is true also for empty arrays
  if ($arg == NULL) {
    return NULL;
  }

  // Keep Twig_Markup objects intact to prepare for later autoescaping support
  if ($arg instanceof Twig_Markup) {
    return $arg;
  }
  if (is_scalar($arg)) {
    return $arg;
  }
  if (is_object($arg)) {
    if (method_exists($arg, '__toString')) {
      return (string) $arg;
    }
    throw new Exception(t('Object of type "@class" cannot be printed.', array(
      '@class' => get_class($arg),
    )));
  }

  // This is a normal render array.
  return render($arg);
}

/**
 * Wrapper around hide() that does not return the content.
 *
 * @see hide
 */
function twig_hide($element) {
  if ($element instanceof TwigReference) {
    $element =& $element
      ->getReference();
    hide($element);
  }

  // @todo Add warning in else case
}

/**
 * Wrapper around show() that does not return the content.
 *
 * @see show
 */
function twig_show($element) {
  if ($element instanceof TwigReference) {
    $element =& $element
      ->getReference();
    show($element);
  }

  // @todo Add warning in else case
}