public function FootnotesFilter::process in Footnotes 8.2

Performs the filter processing.

Parameters

string $text: The text string to be filtered.

string $langcode: The language code of the text to be filtered.

Return value

\Drupal\filter\FilterProcessResult The filtered text, wrapped in a FilterProcessResult object, and possibly with associated assets, cacheability metadata and placeholders.

Overrides FilterInterface::process

File

src/Plugin/Filter/FootnotesFilter.php, line 75

Class

FootnotesFilter: Provides a base filter for Footnotes filter.

Namespace

Drupal\footnotes\Plugin\Filter

Code

public function process($text, $langcode) {

  // Supporting both [fn] and <fn> now. Thanks to fletchgqc
  // http://drupal.org/node/268026.
  // Convert all square brackets to angle brackets. This way all further code
  // just manipulates angle brackets. (Angle brackets are preferred here for
  // the simple reason that square brackets are more tedious to use in
  // regexps).
  if (is_array($text)) {
    implode($text);
  }
  $text = preg_replace('|\\[fn([^\\]]*)\\]|', '<fn$1>', $text);
  $text = preg_replace('|\\[/fn\\]|', '</fn>', $text);
  $text = preg_replace('|\\[footnotes([^\\]]*)\\]|', '<footnotes$1>', $text);

  // Check that there are an even number of open and closing tags.
  // If there is one closing tag missing, append this to the end.
  // If there is more disparity, throw a warning and continue.
  // A closing tag may sometimes be missing when we are processing a teaser
  // and it has been cut in the middle of the footnote.
  // See http://drupal.org/node/253326
  $foo = [];
  $open_tags = preg_match_all("|<fn([^>]*)>|", $text, $foo);
  $close_tags = preg_match_all("|</fn>|", $text, $foo);
  if ($open_tags == $close_tags + 1) {
    $text = $text . '</fn>';
  }
  elseif ($open_tags > $close_tags + 1) {
    trigger_error($this
      ->t("You have unclosed fn tags. This is invalid and will\n        produce unpredictable results."));
  }

  // Before doing the replacement, the callback function needs to know which
  // options to use.
  $this
    ->replaceCallback($this->settings, 'prepare');
  $pattern = '|<fn([^>]*)>(.*?)</fn>|s';
  $text = preg_replace_callback($pattern, [
    $this,
    'replaceCallback',
  ], $text);

  // Replace tag <footnotes> with the list of footnotes.
  // If tag is not present, by default add the footnotes at the end.
  // Thanks to acp on drupal.org for this idea. see
  // http://drupal.org/node/87226.
  $footer = $this
    ->replaceCallback(NULL, 'output footer');
  $pattern = '|(<footnotes([\\ \\/]*)>)|';
  if (preg_match($pattern, $text) > 0) {
    $text = preg_replace($pattern, $footer, $text, 1);
  }
  elseif (!empty($footer)) {
    $text .= "\n\n" . $footer;
  }
  $result = new FilterProcessResult($text);
  $result
    ->setAttachments([
    'library' => [
      'footnotes/footnotes',
    ],
  ]);
  return $result;
}

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