codefilter_prism.module in Code Filter 7

Text filter for highlighting PHP source code.

Note: This isn't really compatible with the prism module. This module is for adding prism support to the codefilter module, which is too, not compatible with the prism filter module.

File

modules/codefilter_prism/codefilter_prism.module

<?php

/**
 * @file
 * Text filter for highlighting PHP source code.
 *
 * Note: This isn't really compatible with the prism module. This module is for
 * adding prism support to the codefilter module, which is too, not compatible
 * with the prism filter module.
 */

/**
 * Implements hook_library().
 */
function codefilter_prism_library() {
  $location = codefilter_prism_return_library_location();
  $libraries['prism'] = array(
    'title' => 'Prism',
    'website' => 'http://prismjs.com',
    'version' => array(),
    'js' => array(
      $location . 'prism.js' => array(),
    ),
    'css' => array(
      $location . 'prism.css' => array(
        'type' => 'file',
        'media' => 'screen',
      ),
    ),
  );
  return $libraries;
}

/**
 * Return appropriate library location.
 */
function codefilter_prism_return_library_location() {
  $file_base = '/libraries/prism/prism.js';

  // Check for a multisite installation.
  if (file_exists(conf_path() . $file_base)) {
    $location = conf_path() . '/libraries/prism/';
  }
  else {

    // Default.
    $location = 'sites/all/libraries/prism/';
  }
  return $location;
}

/**
 * Implements hook_init().
 */
function codefilter_prism_init() {
  drupal_add_library('codefilter_prism', 'prism');
}

/**
 * Processes chunks of escaped PHP code into HTML.
 *
 * @param string $text
 *   The text to process.
 *
 * @return string
 *   HTMl encoded, highlighted PHP code.
 */
function codefilter_prism_process_php($text) {

  // Undo linebreak escaping.
  $text = str_replace('&#10;', "\n", $text);

  // Inline or block level piece?
  $multiline = strpos($text, "\n") !== FALSE;

  // Trim first leading line break.
  $text = preg_replace('@^[ \\t]*[\\n]@', '', $text);
  $text = codefilter_fix_spaces($text);

  // Highlight as PHP.
  $text = '<code class="language-php">' . $text . '</code>';
  $text = $multiline ? '<pre class="codeblock">' . $text . '</pre>' : $text;
  return $text;
}

/**
 * Callback to replace content of the <?php ?> elements.
 *
 * @param array $matches
 *   An array of preg_matches as defined by preg_replace_callback.
 *
 * @return string
 *   Processed text.
 */
function _codefilter_prism_process_php_callback($matches) {
  return codefilter_prism_process_php($matches[1]);
}

/**
 * Processes chunks of escaped code into HTML.
 *
 * @param string $text
 *   Code to convert to HTML.
 * @param string $attributes
 *   Attributes to add to the enclosing HTML tag (eg class="myclass").
 *
 * @return string
 *   HTML containing the text suitable for consumption by prism.
 */
function codefilter_prism_process_code($text, $attributes = '') {

  // Trim first leading line break.
  $text = preg_replace('@^[ \\t]*(\\n|&#10;)@', '', $text);

  // Add language class if one doesn't exist.
  $class_added = FALSE;
  if (strpos($attributes, 'class="') !== FALSE) {
    if (strpos($attributes, 'language-') === FALSE) {
      $attributes = str_replace('class="', 'class="language-php ', $attributes);
      $class_added = TRUE;
    }
  }
  else {
    $attributes .= ' class="language-php"';
    $class_added = TRUE;
  }

  // If the class was already added, the filter has been applied twice, such as
  // with WYSIWYG processing, undo entity encoding.
  if (!$class_added) {
    $text = decode_entities($text);
  }
  $text = codefilter_fix_spaces($text);
  $text = '<code' . $attributes . '>' . $text . '</code>';

  // If the class was newly added, and the code is “block”-level with newlines
  // or encoded newlines, add a wrapping <pre>.
  if ($class_added && (strpos($text, "\n") !== FALSE || strpos($text, '&#10;'))) {
    $text = '<pre class="codeblock">' . $text . '</pre>';
  }
  return $text;
}

/**
 * Callback to replace content of the <code> elements.
 *
 * @param array $matches
 *   An array of matches passed by preg_replace_callback().
 *
 * @return string
 *   A formatted string.
 */
function _codefilter_prism_process_code_callback($matches) {
  return codefilter_prism_process_code($matches[2], $matches[1]);
}

/**
 * Callback to escape content of <code> elements.
 */
function _codefilter_prism_escape_code_tag_callback($matches) {

  // Extract a potentially existing class HTML attribute.
  $attributes = '';
  if (!empty($matches[1]) && preg_match('@class="[^"]+"@', $matches[1], $class_matches)) {
    $attributes = $class_matches[0];
  }
  return codefilter_prism_escape($matches[2], 'code', $attributes);
}

/**
 * Callback to escape content of <?php ?>, [?php ?], <% %>, and [% %] elements.
 */
function _codefilter_prism_escape_php_tag_callback($matches) {
  return codefilter_prism_escape($matches[2], 'php');
}

/**
 * Escape code blocks during input filter 'prepare'.
 *
 * @param string $text
 *   The string to escape.
 * @param string $type
 *   The type of code block, either 'code' or 'php'.
 * @param string $attributes
 *   (optional) The HTML attributes of the code block.
 *
 * @return string
 *   The escaped string.
 */
function codefilter_prism_escape($text, $type = 'code', $attributes = '') {

  // Note, pay attention to odd preg_replace-with-/e behaviour on slashes.
  $text = check_plain($text);

  // Protect newlines from line break converter.
  $text = str_replace(array(
    "\r",
    "\n",
  ), array(
    '',
    '&#10;',
  ), $text);

  // Prepare the class HTML attribute for the prism_code_filter tag.
  if (!empty($attributes)) {
    $attributes = ' ' . $attributes;
  }

  // Add prism_code_filter escape tags.
  $text = "[codefilter_prism_{$type}{$attributes}]{$text}[/codefilter_prism_{$type}]";
  return $text;
}

Functions

Name	Description
codefilter_prism_escape	Escape code blocks during input filter 'prepare'.
codefilter_prism_init	Implements hook_init().
codefilter_prism_library	Implements hook_library().
codefilter_prism_process_code	Processes chunks of escaped code into HTML.
codefilter_prism_process_php	Processes chunks of escaped PHP code into HTML.
codefilter_prism_return_library_location	Return appropriate library location.
_codefilter_prism_escape_code_tag_callback	Callback to escape content of <code> elements.
_codefilter_prism_escape_php_tag_callback	Callback to escape content of <?php ?>, [?php ?], <% %>, and [% %] elements.
_codefilter_prism_process_code_callback	Callback to replace content of the <code> elements.
_codefilter_prism_process_php_callback	Callback to replace content of the <?php ?> elements.