minifyhtml.module in Minify Source HTML 7

Hook and helper functions for the Minify HTML module.

File

minifyhtml.module

<?php

/**
 * @file
 * Hook and helper functions for the Minify HTML module.
 */
define('MINIFYHTML_PLACEHOLDER', 'MINIFYHTML_' . md5(REQUEST_TIME));

/**
 * Implements hook_permission().
 */
function minifyhtml_permission() {
  return array(
    'administer minifyhtml' => array(
      'title' => t('Administer Minify HTML Module'),
      'description' => t('Perform administration tasks for Minify HTML module.'),
    ),
  );
}

/**
 * Implements hook_menu().
 */
function minifyhtml_menu() {
  $items['admin/config/development/performance/default'] = array(
    'title' => 'Performance',
    'type' => MENU_DEFAULT_LOCAL_TASK,
    'weight' => 1,
  );
  $items['admin/config/development/performance/minifyhtml'] = array(
    'access arguments' => array(
      'administer minifyhtml',
    ),
    'file' => 'minifyhtml.admin.inc',
    'page callback' => 'drupal_get_form',
    'page arguments' => array(
      'minifyhtml_settings_form',
    ),
    'title' => 'Minify Source HTML settings',
    'description' => 'Settings that control how the HTML is minified',
    'type' => MENU_LOCAL_TASK,
    'weight' => 2,
  );
  return $items;
}

/**
 * Implements hook_help().
 */
function minifyhtml_help($path, $arg) {
  switch ($path) {
    case 'admin/help#minifyhtml':
      $filepath = dirname(__FILE__) . '/README.md';
      if (file_exists($filepath)) {
        $readme = file_get_contents($filepath);
      }
      else {
        $filepath = dirname(__FILE__) . '/README.txt';
        if (file_exists($filepath)) {
          $readme = file_get_contents($filepath);
        }
      }
      if (!isset($readme)) {
        return NULL;
      }
      if (module_exists('markdown')) {
        $filters = module_invoke('markdown', 'filter_info');
        $info = $filters['filter_markdown'];
        if (function_exists($info['process callback'])) {
          $output = $info['process callback']($readme, NULL);
        }
        else {
          $output = '<pre>' . $readme . '</pre>';
        }
      }
      else {
        $output = '<pre>' . $readme . '</pre>';
      }
      return $output;
  }
}

/**
 * Implements hook_FORM_ID_alter().
 */
function minifyhtml_form_system_performance_settings_alter(&$form, &$form_state, $form_id) {
  if (user_access('administer minifyhtml')) {
    $form['bandwidth_optimization']['minifyhtml_minify'] = array(
      '#type' => 'checkbox',
      '#title' => t('Minified Source HTML.'),
      '#description' => t('Toggle minified HTML on or off.'),
      '#default_value' => variable_get('minifyhtml_minify', 0),
    );
  }
}

/**
 * Implements hook_exit().
 */
function minifyhtml_exit() {
  if (variable_get('minifyhtml_minify', 0)) {

    // Get current path value.
    $current_path = function_exists('current_path') ? current_path() : $_GET['q'];

    // The content type of the page must be text/html to proceed. All other
    // content types must be ignored - the name of the module is minifyhtml
    // after all.
    // Make sure to exclude image style images (is this even required
    // anymore??).
    // Make sure the buffer has a length.
    if (stripos(drupal_get_http_header('content-type'), 'text/html') !== FALSE && !is_file($current_path) && ob_get_length()) {

      // Catch the output buffer. Converted from ob_get_clean().
      $page = ob_get_contents();

      // If the content should be encoded, try to decode it.
      $decoded = FALSE;
      if (variable_get('page_compression', TRUE) && extension_loaded('zlib')) {
        $decoded = @gzinflate(substr(substr($page, 10), 0, -8));
        if ($decoded) {
          $page = $decoded;
        }
      }

      // Minify the HTML.
      minifyhtml_minify($page);

      // If the content was decoded before being minified, it needs to be
      // re-encoded.
      if (variable_get('page_compression', TRUE) && extension_loaded('zlib') && $decoded) {
        $page = gzencode($page, 9, FORCE_GZIP);
      }

      // If, for some reason, the minification failed and some artifacts still
      // remain in the source this will cause a mostly white unusable page. The
      // fallback for this scenario is to revert and notify.
      if (strpos($page, '%' . MINIFYHTML_PLACEHOLDER)) {
        $page = ob_get_contents();
        watchdog('minifyhtml', 'Minifyhtml failed on %path', array(
          '%path' => $current_path,
        ), WATCHDOG_WARNING, $current_path);
      }

      // Re-populate the output buffer.
      ob_clean();
      print $page;
    }
  }
}

/**
 * Implements hook_module_implements_alter().
 */
function minifyhtml_module_implements_alter(&$implementations, $hook) {

  // Move this module's hook_exit() to the end of the call order.
  if ($hook == 'exit' && isset($implementations['minifyhtml'])) {
    $group = $implementations['minifyhtml'];
    unset($implementations['minifyhtml']);
    $implementations['minifyhtml'] = $group;
  }
}

/**
 * Helper function to minify HTML.
 *
 * @param string $page
 *   The entire html source of the page.
 */
function minifyhtml_minify(&$page) {
  $callbacks = array(
    'minifyhtml_placeholder_callback_textarea' => '/\\s*<textarea(\\b[^>]*?>[\\s\\S]*?<\\/textarea>)\\s*/i',
    'minifyhtml_placeholder_callback_pre' => '/\\s*<pre(\\b[^>]*?>[\\s\\S]*?<\\/pre>)\\s*/i',
    'minifyhtml_placeholder_callback_iframe' => '/\\s*<iframe(\\b[^>]*?>[\\s\\S]*?<\\/iframe>)\\s*/i',
    'minifyhtml_placeholder_callback_script' => '/\\s*<script(\\b[^>]*?>[\\s\\S]*?<\\/script>)\\s*/i',
    'minifyhtml_placeholder_callback_style' => '/\\s*<style(\\b[^>]*?>[\\s\\S]*?<\\/style>)\\s*/i',
  );

  // Only strip HTML comments if required.
  if (variable_get('minifyhtml_strip_comments', TRUE)) {
    $callbacks['minifyhtml_remove_html_comment'] = '/<!--([\\s\\S]*?)-->/';
  }
  foreach ($callbacks as $callback => $pattern) {
    $content = minifyhtml_minify_callback($pattern, $callback, $page);
    if (!is_null($content)) {
      $page = $content;
    }
  }

  // Minify the page.
  minifyhtml_minify_html($page);

  // Restore all values that are currently represented by a placeholder.
  global $_minifyhtml_placeholders;
  if (!empty($_minifyhtml_placeholders)) {
    $page = str_replace(array_keys($_minifyhtml_placeholders), array_values($_minifyhtml_placeholders), $page);
  }
}

/**
 * Helper function to catch any errors with preg_replace().
 *
 * @param string $pattern
 *   The pattern for the search.
 * @param string $callback
 *   The callback function to use.
 * @param string $content
 *   The subject of the search.
 *
 * @return string
 *   The content with placeholders.
 */
function minifyhtml_minify_callback($pattern, $callback, $content) {
  $content = preg_replace_callback($pattern, $callback, $content);
  $error = preg_last_error();
  if ($error > PREG_NO_ERROR) {
    watchdog('minifyhtml', 'Preg error. The error code is %error. You can view what this error code is by viewing http://php.net/manual/en/function.preg-last-error.php', array(
      '%error' => $error,
    ));
  }
  return $content;
}

/**
 * Helper function to add place holder for <textarea> tag.
 *
 * @param array $matches
 *   Matches from initial preg_replace().
 *
 * @return string
 *   The placeholder string.
 */
function minifyhtml_placeholder_callback_textarea(array $matches) {
  return minifyhtml_placeholder_replace(trim($matches[0]));
}

/**
 * Helper function to add place holder for <pre> tag.
 *
 * @param array $matches
 *   Matches from initial preg_replace().
 *
 * @return string
 *   The placeholder string.
 */
function minifyhtml_placeholder_callback_pre(array $matches) {
  return minifyhtml_placeholder_replace(trim($matches[0]));
}

/**
 * Helper function to add place holder for <iframe> tag.
 *
 * @param array $matches
 *   Matches from initial preg_replace().
 *
 * @return string
 *   The placeholder string.
 */
function minifyhtml_placeholder_callback_iframe(array $matches) {
  $iframe = preg_replace('/^\\s+|\\s+$/m', '', $matches[0]);
  return minifyhtml_placeholder_replace(trim($iframe));
}

/**
 * Helper function to add place holder for <script> tag.
 *
 * @param array $matches
 *   Matches from initial preg_replace().
 *
 * @return string
 *   The placeholder string.
 */
function minifyhtml_placeholder_callback_script(array $matches) {
  $search = array();
  $replace = array();

  // Only strip multi-line comments in <script> if required.
  if (variable_get('minifyhtml_strip_comments', TRUE)) {
    $search[] = '!/\\*.*?\\*/!s';
    $replace[] = '';
  }

  // Trim each line.
  $search[] = '/^\\s+|\\s+$/m';
  $replace[] = "\n";

  // Remove multiple empty line.
  $search[] = '/\\n(\\s*\\n)+/';
  $replace[] = "\n";
  $script = preg_replace($search, $replace, $matches[0]);
  return minifyhtml_placeholder_replace(trim($script));
}

/**
 * Helper function to add place holder for <style> tag.
 *
 * @param array $matches
 *   Matches from initial preg_replace().
 *
 * @return string
 *   The placeholder string.
 */
function minifyhtml_placeholder_callback_style(array $matches) {
  $search = array();
  $replace = array();

  // Only strip multi-line comments in <style> if required.
  if (variable_get('minifyhtml_strip_comments', TRUE)) {
    $search[] = '!/\\*.*?\\*/!s';
    $replace[] = '';
  }

  // Trim each line.
  $search[] = '/^\\s+|\\s+$/m';
  $replace[] = '';
  $style = preg_replace($search, $replace, $matches[0]);
  return minifyhtml_placeholder_replace(trim($style));
}

/**
 * Helper function to add tag key and value for further replacement.
 *
 * @param string $content
 *   String before the placeholder replacement.
 *
 * @return string
 *   The placeholder string.
 */
function minifyhtml_placeholder_replace($content) {
  global $_minifyhtml_placeholders;

  // PHP 7.2 fix, if the variable is not set count() will emit a warning.
  if (!isset($_minifyhtml_placeholders)) {
    $_minifyhtml_placeholders = array();
  }
  $placeholder = '%' . MINIFYHTML_PLACEHOLDER . count($_minifyhtml_placeholders) . '%';
  $_minifyhtml_placeholders[$placeholder] = $content;
  return $placeholder;
}

/**
 * Helper function to remove HTML comments.
 *
 * Comments containing IE conditionals will be ignored.
 *
 * @param array $matches
 *   Matches from initial preg_replace().
 *
 * @return string
 *   String with removed HTML comments.
 */
function minifyhtml_remove_html_comment(array $matches) {
  return 0 === strpos($matches[1], '[') || FALSE !== strpos($matches[1], '<![') ? $matches[0] : '';
}

/**
 * Helper function to minify the HTML.
 *
 * @param string $page
 *   The HTML source of the page.
 */
function minifyhtml_minify_html(&$page) {
  $search = array();
  $replace = array();

  // Remove whitespaces after tags, except space.
  $search[] = '/\\>[^\\S ]+/s';
  $replace[] = '>';

  // Remove whitespaces before tags, except space.
  $search[] = '/[^\\S ]+\\</s';
  $replace[] = '<';

  // Shorten multiple whitespace sequences.
  $search[] = '/(\\s)+/s';
  $replace[] = '\\1';

  // Remove whitespaces around block/undisplayed elements.
  $search[] = '/\\s+(<\\/?(?:area|base(?:font)?|blockquote|body' . '|caption|center|col(?:group)?|dd|dir|div|dl|dt|fieldset|form' . '|frame(?:set)?|h[1-6]|head|hr|html|legend|li|link|map|menu|meta' . '|ol|opt(?:group|ion)|p|param|t(?:able|body|head|d|h||r|foot|itle)' . '|ul)\\b[^>]*>)/i';
  $replace[] = '$1';

  // Trim each line.
  $search[] = '/^\\s+|\\s+$/m';
  $replace[] = '';
  $page = preg_replace($search, $replace, $page);
}

Functions

Name	Description
minifyhtml_exit	Implements hook_exit().
minifyhtml_form_system_performance_settings_alter	Implements hook_FORM_ID_alter().
minifyhtml_help	Implements hook_help().
minifyhtml_menu	Implements hook_menu().
minifyhtml_minify	Helper function to minify HTML.
minifyhtml_minify_callback	Helper function to catch any errors with preg_replace().
minifyhtml_minify_html	Helper function to minify the HTML.
minifyhtml_module_implements_alter	Implements hook_module_implements_alter().
minifyhtml_permission	Implements hook_permission().
minifyhtml_placeholder_callback_iframe	Helper function to add place holder for <iframe> tag.
minifyhtml_placeholder_callback_pre	Helper function to add place holder for <pre> tag.
minifyhtml_placeholder_callback_script	Helper function to add place holder for <script> tag.
minifyhtml_placeholder_callback_style	Helper function to add place holder for <style> tag.
minifyhtml_placeholder_callback_textarea	Helper function to add place holder for <textarea> tag.
minifyhtml_placeholder_replace	Helper function to add tag key and value for further replacement.
minifyhtml_remove_html_comment	Helper function to remove HTML comments.

Constants

Name	Description
MINIFYHTML_PLACEHOLDER	@file Hook and helper functions for the Minify HTML module.