system.admin.inc

<?php
// $Id$

/**
 * @file
 * Admin page callbacks for the system module.
 */

/**
 * Menu callback; Provide the administration overview page.
 */
function system_main_admin_page($arg = NULL) {
  // If we received an argument, they probably meant some other page.
  // Let's 404 them since the menu system cannot be told we do not
  // accept arguments.
  if (isset($arg) && substr($arg, 0, 3) != 'by-') {
    return drupal_not_found();
  }

  // Check for status report errors.
  if (system_status(TRUE) && user_access('administer site configuration')) {
    drupal_set_message(t('One or more problems were detected with your Drupal installation. Check the <a href="@status">status report</a> for more information.', array('@status' => url('admin/reports/status'))), 'error');
  }
  $blocks = array();
  if ($admin = db_query("SELECT menu_name, mlid FROM {menu_links} WHERE link_path = 'admin' AND module = 'system'")->fetchAssoc()) {
    $result = db_query("
      SELECT m.*, ml.*
      FROM {menu_links} ml
      INNER JOIN {menu_router} m ON ml.router_path = m.path
      WHERE ml.link_path != 'admin/help' AND menu_name = :menu_name AND ml.plid = :mlid AND hidden = 0", $admin, array('fetch' => PDO::FETCH_ASSOC));
    foreach ($result as $item) {
      _menu_link_translate($item);
      if (!$item['access']) {
        continue;
      }
      // The link 'description' either derived from the hook_menu 'description'
      // or entered by the user via menu module is saved as the title attribute.
      if (!empty($item['localized_options']['attributes']['title'])) {
        $item['description'] = $item['localized_options']['attributes']['title'];
      }
      $block = $item;
      $block['content'] = '';
      $block['show'] = FALSE;
      if ($item['block_callback'] && function_exists($item['block_callback'])) {
        $function = $item['block_callback'];
        $block['content'] .= $function();
      }
      $content = system_admin_menu_block($item);
      if ((isset($item['page_callback']) && !in_array($item['page_callback'], array('system_admin_menu_block_page', 'system_admin_config_page', 'system_settings_overview'))) || count($content)) {
        // Only show blocks for items which are not containers, or those which
        // are containers and do have items we can show.
        $block['show'] = TRUE;
        if (empty($content)) {
          // If no items found below, but access checks did not fail, show.
          $block['title'] = l($item['title'], $item['href'], $item['localized_options']);
        }
        else {
          // Theme items below.
          $block['content'] .= theme('admin_block_content', array('content' => $content));
        }
      }
      // Prepare for sorting as in function _menu_tree_check_access().
      // The weight is offset so it is always positive, with a uniform 5-digits.
      $blocks[(50000 + $item['weight']) . ' ' . $item['title'] . ' ' . $item['mlid']] = $block;
    }
  }
  if ($blocks) {
    ksort($blocks);
    return theme('admin_page', array('blocks' => $blocks));
  }
  else {
    return t('You do not have any administrative items.');
  }
}

/**
 * Menu callback; Provide the administration overview page.
 */
function system_admin_config_page() {
  // Check for status report errors.
  if (system_status(TRUE) && user_access('administer site configuration')) {
    drupal_set_message(t('One or more problems were detected with your Drupal installation. Check the <a href="@status">status report</a> for more information.', array('@status' => url('admin/reports/status'))), 'error');
  }
  $blocks = array();
  if ($admin = db_query("SELECT menu_name, mlid FROM {menu_links} WHERE link_path = 'admin/config' AND module = 'system'")->fetchAssoc()) {
    $result = db_query("
      SELECT m.*, ml.*
      FROM {menu_links} ml
      INNER JOIN {menu_router} m ON ml.router_path = m.path
      WHERE ml.link_path != 'admin/help' AND menu_name = :menu_name AND ml.plid = :mlid AND hidden = 0", $admin, array('fetch' => PDO::FETCH_ASSOC));
    foreach ($result as $item) {
      _menu_link_translate($item);
      if (!$item['access']) {
        continue;
      }
      // The link 'description' either derived from the hook_menu 'description'
      // or entered by the user via menu module is saved as the title attribute.
      if (!empty($item['localized_options']['attributes']['title'])) {
        $item['description'] = $item['localized_options']['attributes']['title'];
      }
      $block = $item;
      $block['content'] = '';
      $block['show'] = TRUE;
      if ($item['block_callback'] && function_exists($item['block_callback'])) {
        $function = $item['block_callback'];
        $block['content'] .= $function();
      }
      $block['content'] .= theme('admin_block_content', array('content' => system_admin_menu_block($item)));
      // Prepare for sorting as in function _menu_tree_check_access().
      // The weight is offset so it is always positive, with a uniform 5-digits.
      $blocks[(50000 + $item['weight']) . ' ' . $item['title'] . ' ' . $item['mlid']] = $block;
    }
  }
  if ($blocks) {
    ksort($blocks);
    return theme('admin_page', array('blocks' => $blocks));
  }
  else {
    return t('You do not have any administrative items.');
  }
}

/**
 * Provide a single block from the administration menu as a page.
 * This function is often a destination for these blocks.
 * For example, 'admin/structure/types' needs to have a destination to be valid
 * in the Drupal menu system, but too much information there might be
 * hidden, so we supply the contents of the block.
 *
 * @return
 *   The output HTML.
 */
function system_admin_menu_block_page() {
  $item = menu_get_item();
  if ($content = system_admin_menu_block($item)) {
    $output = theme('admin_block_content', array('content' => $content));
  }
  else {
    $output = t('You do not have any administrative items.');
  }
  return $output;
}

/**
 * Menu callback; prints a listing of admin tasks for each installed module.
 */
function system_admin_by_module() {

  $module_info = system_get_info('module');
  $menu_items = array();
  $help_arg = module_exists('help') ? drupal_help_arg() : FALSE;

  foreach ($module_info as $module => $info) {
    if ($module == 'help') {
      continue;
    }

    $admin_tasks = system_get_module_admin_tasks($module);

    // Only display a section if there are any available tasks.
    if (count($admin_tasks)) {

      // Check for help links.
      if ($help_arg && module_invoke($module, 'help', "admin/help#$module", $help_arg)) {
        $admin_tasks[100] = l(t('Get help'), "admin/help/$module");
      }

      // Sort.
      ksort($admin_tasks);

      $menu_items[$info['name']] = array($info['description'], $admin_tasks);
    }
  }
  return theme('system_admin_by_module', array('menu_items' => $menu_items));
}

/**
 * Menu callback; displays a module's settings page.
 */
function system_settings_overview() {
  // Check database setup if necessary
  if (function_exists('db_check_setup') && empty($_POST)) {
    db_check_setup();
  }

  $item = menu_get_item('admin/config');
  $content = system_admin_menu_block($item);

  $output = theme('admin_block_content', array('content' => $content));

  return $output;
}

/**
 * Retrieve the list of themes that are not hidden.
 */
function _system_theme_list() {
  // Get current list of themes.
  $themes = system_rebuild_theme_data();

  // Remove hidden themes from the display list.
  foreach ($themes as $theme_key => $theme) {
    if (!empty($theme->info['hidden'])) {
      unset($themes[$theme_key]);
    }
  }

  uasort($themes, 'system_sort_modules_by_info_name');
  return $themes;
}

/**
 * Menu callback; displays a listing of all themes.
 */
function system_themes_page() {
  // Get current list of themes.
  $themes =& _system_theme_list();

  $theme_default = variable_get('theme_default', 'garland');
  $theme_groups  = array();

  foreach ($themes as &$theme) {
    $admin_theme_options[$theme->name] = $theme->info['name'];
    $theme->is_default = ($theme->name == $theme_default);

    // Identify theme screenshot.
    $theme->screenshot = NULL;
    // Create a list which includes the current theme and all its base themes.
    if (isset($themes[$theme->name]->base_themes)) {
      $theme_keys = array_keys($themes[$theme->name]->base_themes);
      $theme_keys[] = $theme->name;
    }
    else {
      $theme_keys = array($theme->name);
    }
    // Look for a screenshot in the current theme or in its closest ancestor.
    foreach (array_reverse($theme_keys) as $theme_key) {
      if (isset($themes[$theme_key]) && file_exists($themes[$theme_key]->info['screenshot'])) {
        $theme->screenshot = array(
          'path' => $themes[$theme_key]->info['screenshot'],
          'alt' => t('Screenshot for !theme theme', array('!theme' => $theme->info['name'])),
          'title' => t('Screenshot for !theme theme', array('!theme' => $theme->info['name'])),
          'attributes' => array('class' => array('screenshot')),
          'getsize' => FALSE,
        );
        break;
      }
    }

    if (empty($theme->status)) {
     // Ensure this theme is compatible with this version of core.
     // Require the 'content' region to make sure the main page
     // content has a common place in all themes.
      $theme->incompatible_core = !isset($theme->info['core']) || ($theme->info['core'] != DRUPAL_CORE_COMPATIBILITY) || (!isset($theme->info['regions']['content']));
      $theme->incompatible_php = version_compare(phpversion(), $theme->info['php']) < 0;
    }
    $query['token'] = drupal_get_token('system-theme-operation-link');
    $theme->operations = array();
    if (!empty($theme->status) || !$theme->incompatible_core && !$theme->incompatible_php) {
      // Create the operations links.
      $query['theme'] = $theme->name;
      if (drupal_theme_access($theme)) {
        $theme->operations[] = array(
          'title' => t('Settings'),
          'href' => 'admin/appearance/settings/' . $theme->name,
          'attributes' => array('title' => t('Settings for !theme theme', array('!theme' => $theme->info['name']))),
        );
      }
      if (!empty($theme->status)) {
        if (!$theme->is_default) {
          $theme->operations[] = array(
            'title' => t('Disable'),
            'href' => 'admin/appearance/disable',
            'query' => $query,
            'attributes' => array('title' => t('Disable !theme theme', array('!theme' => $theme->info['name']))),
          );
          $theme->operations[] = array(
            'title' => t('Set default'),
            'href' => 'admin/appearance/default',
            'query' => $query,
            'attributes' => array('title' => t('Set !theme as default theme', array('!theme' => $theme->info['name']))),
          );
        }
      }
      else {
        $theme->operations[] = array(
          'title' => t('Enable'),
          'href' => 'admin/appearance/enable',
          'query' => $query,
          'attributes' => array('title' => t('Enable !theme theme', array('!theme' => $theme->info['name']))),
        );
      }
    }

    // Add notes to default and administration theme.
    $theme->notes = array();
    $theme->classes = array();
    if ($theme->is_default) {
      $theme->classes[] = 'theme-default';
      $theme->notes[] = t('default theme');
    }

    // Sort enabled and disabled themes into their own groups.
    $theme_groups[$theme->status ? 'enabled' : 'disabled'][] = $theme;
  }

  // There are two possible theme groups.
  $theme_group_titles = array(
    'enabled' => format_plural(count($theme_groups['enabled']), 'Enabled theme', 'Enabled themes'),
  );
  if (!empty($theme_groups['disabled'])) {
    $theme_group_titles['disabled'] = format_plural(count($theme_groups['disabled']), 'Disabled theme', 'Disabled themes');
  };

  uasort($theme_groups['enabled'], 'system_sort_themes');
  drupal_alter('system_themes_page', $theme_groups);

  $admin_form = drupal_get_form('system_themes_admin_form', $admin_theme_options);
  return theme('system_themes_page', array('theme_groups' => $theme_groups, 'theme_group_titles' => $theme_group_titles)) . drupal_render($admin_form);
}

/**
 * Form to select the administration theme.
 *
 * @ingroup forms
 * @see system_themes_admin_form_submit()
 */
function system_themes_admin_form($form, &$form_state, $theme_options) {
  // Administration theme settings.
  $form['admin_theme'] = array(
    '#type' => 'fieldset',
    '#title' => t('Administration theme'),
  );
  $form['admin_theme']['admin_theme'] = array(
    '#type' => 'select',
    '#options' => array(0 => t('Default theme')) + $theme_options,
    '#title' => t('Administration theme'),
    '#description' => t('Choose "Default theme" to always use the same theme as the rest of the site.'),
    '#default_value' => variable_get('admin_theme', 0),
  );
  $form['admin_theme']['node_admin_theme'] = array(
    '#type' => 'checkbox',
    '#title' => t('Use the administration theme when editing or creating content'),
    '#default_value' => variable_get('node_admin_theme', '0'),
  );
  $form['admin_theme']['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Save configuration'),
  );
  return $form;
}

/**
 * Process system_themes_admin_form form submissions.
 */
function system_themes_admin_form_submit($form, &$form_state) {
  drupal_set_message(t('The configuration options have been saved.'));
  variable_set('admin_theme', $form_state['values']['admin_theme']);
  variable_set('node_admin_theme', $form_state['values']['node_admin_theme']);
}

/**
 * Menu callback; Enables a theme.
 */
function system_theme_enable() {
  if (isset($_REQUEST['theme']) && isset($_REQUEST['token']) && drupal_valid_token($_REQUEST['token'], 'system-theme-operation-link')) {
    $theme = $_REQUEST['theme'];
    // Get current list of themes.
    $themes =& _system_theme_list();

    // Check if the specified theme is one recognized by the system.
    if (!empty($themes[$theme])) {
      theme_enable(array($theme));
      drupal_set_message(t('The %theme theme has been enabled.', array('%theme' => $themes[$theme]->info['name'])));
    }
    else {
      drupal_set_message(t('The %theme theme was not found.', array('%theme' => $theme)), 'error');
    }
    drupal_goto('admin/appearance');
  }
  return drupal_access_denied();
}

/**
 * Menu callback; Disables a theme.
 */
function system_theme_disable() {
  if (isset($_REQUEST['theme']) && isset($_REQUEST['token']) && drupal_valid_token($_REQUEST['token'], 'system-theme-operation-link')) {
    $theme = $_REQUEST['theme'];
    // Get current list of themes.
    $themes =& _system_theme_list();

    // Check if the specified theme is one recognized by the system.
    if (!empty($themes[$theme])) {
      if ($theme == variable_get('theme_default', 'garland')) {
        // Don't disable the default theme.
        drupal_set_message(t('%theme is the default theme and cannot be disabled.', array('%theme' => $themes[$theme]->info['name'])), 'error');
      }
      else {
        theme_disable(array($theme));
        drupal_set_message(t('The %theme theme has been disabled.', array('%theme' => $themes[$theme]->info['name'])));
      }
    }
    else {
      drupal_set_message(t('The %theme theme was not found.', array('%theme' => $theme)), 'error');
    }
    drupal_goto('admin/appearance');
  }
  return drupal_access_denied();
}

/**
 * Menu callback; Set the default theme.
 */
function system_theme_default() {
  if (isset($_REQUEST['theme']) && isset($_REQUEST['token']) && drupal_valid_token($_REQUEST['token'], 'system-theme-operation-link')) {
    $theme = $_REQUEST['theme'];
    // Get current list of themes.
    $themes =& _system_theme_list();

    // Check if the specified theme is one recognized by the system.
    if (!empty($themes[$theme])) {
      // Enable the theme if it is currently disabled.
      if (empty($themes[$theme]->status)) {
       theme_enable(array($theme));
      }
      // Set the default theme.
      variable_set('theme_default', $theme);
      // The status message depends on whether an admin theme is currently in use.
      $admin_theme = variable_get('admin_theme', 0);
      if ($admin_theme != $theme) {
        drupal_set_message(t('Please note that the administration theme is still set to the %admin_theme theme; consequently, the theme on this page remains unchanged. All non-administrative sections of the site, however, will show the selected %selected_theme theme by default.', array(
          '%admin_theme' => $themes[$admin_theme]->info['name'],
          '%selected_theme' => $themes[$theme]->info['name'],
        )));
      }
      else {
        drupal_set_message(t('%theme is now the default theme.', array('%theme' => $themes[$theme]->info['name'])));
      }
    }
    else {
      drupal_set_message(t('The %theme theme was not found.', array('%theme' => $theme)), 'error');
    }
    drupal_goto('admin/appearance');
  }
  return drupal_access_denied();
}

/**
 * Form builder; display theme configuration for entire site and individual themes.
 *
 * @param $key
 *   A theme name.
 * @return
 *   The form structure.
 * @ingroup forms
 * @see system_theme_settings_submit()
 */
function system_theme_settings($form, &$form_state, $key = '') {
  // Default settings are defined in theme_get_setting() in includes/theme.inc
  if ($key) {
    $var = 'theme_' . $key . '_settings';
    $themes = system_rebuild_theme_data();
    $features = $themes[$key]->info['features'];
  }
  else {
    $var = 'theme_settings';
  }

  $form['var'] = array('#type' => 'hidden', '#value' => $var);

  // Toggle settings
  $toggles = array(
    'logo'                      => t('Logo'),
    'name'                      => t('Site name'),
    'slogan'                    => t('Site slogan'),
    'node_user_picture'         => t('User pictures in posts'),
    'comment_user_picture'      => t('User pictures in comments'),
    'comment_user_verification' => t('User verification status in comments'),
    'favicon'                   => t('Shortcut icon'),
    'main_menu'                 => t('Main menu'),
    'secondary_menu'            => t('Secondary menu'),
  );

  // Some features are not always available
  $disabled = array();
  if (!variable_get('user_pictures', 0)) {
    $disabled['toggle_node_user_picture'] = TRUE;
    $disabled['toggle_comment_user_picture'] = TRUE;
  }

  $form['theme_settings'] = array(
    '#type' => 'fieldset',
    '#title' => t('Toggle display'),
    '#description' => t('Enable or disable the display of certain page elements.'),
  );
  foreach ($toggles as $name => $title) {
    if ((!$key) || in_array($name, $features)) {
      $form['theme_settings']['toggle_' . $name] = array('#type' => 'checkbox', '#title' => $title, '#default_value' => theme_get_setting('toggle_' . $name, $key));
      // Disable checkboxes for features not supported in the current configuration.
      if (isset($disabled['toggle_' . $name])) {
        $form['theme_settings']['toggle_' . $name]['#disabled'] = TRUE;
      }
    }
  }

  if (!element_children($form['theme_settings'])) {
    // If there is no element in the theme settings fieldset then do not show
    // it -- but keep it in the form if another module wants to alter.
    $form['theme_settings']['#access'] = FALSE;
  }

  // Logo settings
  if ((!$key) || in_array('logo', $features)) {
    $form['logo'] = array(
      '#type' => 'fieldset',
      '#title' => t('Logo image settings'),
      '#description' => t('If toggled on, the following logo will be displayed.'),
      '#attributes' => array('class' => array('theme-settings-bottom')),
    );
    $form['logo']['default_logo'] = array(
      '#type' => 'checkbox',
      '#title' => t('Use the default logo'),
      '#default_value' => theme_get_setting('default_logo', $key),
      '#tree' => FALSE,
      '#description' => t('Check here if you want the theme to use the logo supplied with it.')
    );
    $form['logo']['settings'] = array(
      '#type' => 'container',
      '#states' => array(
        // Hide the logo settings when using the default logo.
        'invisible' => array(
          'input[name="default_logo"]' => array('checked' => TRUE),
        ),
      ),
    );
    $logo_path = theme_get_setting('logo_path', $key);
    // If $logo_path is a public:// URI, display the path relative to the files
    // directory; stream wrappers are not end-user friendly.
    if (file_uri_scheme($logo_path) == 'public') {
      $logo_path = file_uri_target($logo_path);
    }
    $form['logo']['settings']['logo_path'] = array(
      '#type' => 'textfield',
      '#title' => t('Path to custom logo'),
      '#default_value' => $logo_path,
      '#description' => t('The path to the file you would like to use as your logo file instead of the default logo.'),
    );
    $form['logo']['settings']['logo_upload'] = array(
      '#type' => 'file',
      '#title' => t('Upload logo image'),
      '#maxlength' => 40,
      '#description' => t("If you don't have direct file access to the server, use this field to upload your logo.")
    );
  }

  if ((!$key) || in_array('favicon', $features)) {
    $form['favicon'] = array(
      '#type' => 'fieldset',
      '#title' => t('Shortcut icon settings'),
      '#description' => t("Your shortcut icon, or 'favicon', is displayed in the address bar and bookmarks of most browsers."),
    );
    $form['favicon']['default_favicon'] = array(
      '#type' => 'checkbox',
      '#title' => t('Use the default shortcut icon.'),
      '#default_value' => theme_get_setting('default_favicon', $key),
      '#description' => t('Check here if you want the theme to use the default shortcut icon.')
    );
    $form['favicon']['settings'] = array(
      '#type' => 'container',
      '#states' => array(
        // Hide the favicon settings when using the default favicon.
        'invisible' => array(
          'input[name="default_favicon"]' => array('checked' => TRUE),
        ),
      ),
    );
    $favicon_path = theme_get_setting('favicon_path', $key);
    // If $favicon_path is a public:// URI, display the path relative to the
    // files directory; stream wrappers are not end-user friendly.
    if (file_uri_scheme($favicon_path) == 'public') {
      $favicon_path = file_uri_target($favicon_path);
    }
    $form['favicon']['settings']['favicon_path'] = array(
      '#type' => 'textfield',
      '#title' => t('Path to custom icon'),
      '#default_value' => $favicon_path,
      '#description' => t('The path to the image file you would like to use as your custom shortcut icon.')
    );
    $form['favicon']['settings']['favicon_upload'] = array(
      '#type' => 'file',
      '#title' => t('Upload icon image'),
      '#description' => t("If you don't have direct file access to the server, use this field to upload your shortcut icon.")
    );
  }

  if ($key) {
    // Call engine-specific settings.
    $function = $themes[$key]->prefix . '_engine_settings';
    if (function_exists($function)) {
      $form['engine_specific'] = array(
        '#type' => 'fieldset',
        '#title' => t('Theme-engine-specific settings'),
        '#description' => t('These settings only exist for the themes based on the %engine theme engine.', array('%engine' => $themes[$key]->prefix)),
      );
      $function($form, $form_state);
    }

    // Create a list which includes the current theme and all its base themes.
    if (isset($themes[$key]->base_themes)) {
      $theme_keys = array_keys($themes[$key]->base_themes);
      $theme_keys[] = $key;
    }
    else {
      $theme_keys = array($key);
    }

    // Save the name of the current theme (if any), so that we can temporarily
    // override the current theme and allow theme_get_setting() to work
    // without having to pass the theme name to it.
    $default_theme = !empty($GLOBALS['theme_key']) ? $GLOBALS['theme_key'] : NULL;
    $GLOBALS['theme_key'] = $key;

    // Process the theme and all its base themes.
    foreach ($theme_keys as $theme) {
      // Include the theme-settings.php file.
      $filename = DRUPAL_ROOT . '/' . str_replace("/$theme.info", '', $themes[$theme]->filename) . '/theme-settings.php';
      if (file_exists($filename)) {
        require_once $filename;
      }

      // Call theme-specific settings.
      $function = $theme . '_form_system_theme_settings_alter';
      if (function_exists($function)) {
        $function($form, $form_state);
      }
    }

    // Restore the original current theme.
    if (!is_null($default_theme)) {
      $GLOBALS['theme_key'] = $default_theme;
    }
    else {
      unset($GLOBALS['theme_key']);
    }
  }

  $form = system_settings_form($form, FALSE);
  // We don't want to call system_settings_form_submit(), so change #submit.
  array_pop($form['#submit']);
  $form['#submit'][] = 'system_theme_settings_submit';
  $form['#validate'][] = 'system_theme_settings_validate';
  return $form;
}

/**
 * Validator for the system_theme_settings() form.
 */
function system_theme_settings_validate($form, &$form_state) {
  // Handle file uploads.
  $validators = array('file_validate_is_image' => array());

  // Check for a new uploaded logo.
  $file = file_save_upload('logo_upload', $validators);
  if (isset($file)) {
    // File upload was attempted.
    if ($file) {
      // Put the temporary file in form_values so we can save it on submit.
      $form_state['values']['logo_upload'] = $file;
    }
    else {
      // File upload failed.
      form_set_error('logo_upload', t('The logo could not be uploaded.'));
    }
  }

  // Check for a new uploaded favicon.
  $file = file_save_upload('favicon_upload');
  if (isset($file)) {
    // File upload was attempted.
    if ($file) {
      // Put the temporary file in form_values so we can save it on submit.
      $form_state['values']['favicon_upload'] = $file;
    }
    else {
      // File upload failed.
      form_set_error('logo_upload', t('The favicon could not be uploaded.'));
    }
  }

  // If the user provided a path for a logo or favicon file, make sure a file
  // exists at that path.
  if ($form_state['values']['logo_path']) {
    $path = _system_theme_settings_validate_path($form_state['values']['logo_path']);
    if (!$path) {
      form_set_error('logo_path', t('The custom logo path is invalid.'));
    }
  }
  if ($form_state['values']['favicon_path']) {
    $path = _system_theme_settings_validate_path($form_state['values']['favicon_path']);
    if (!$path) {
      form_set_error('favicon_path', t('The custom favicon path is invalid.'));
    }
  }
}

/**
 * Helper function for the system_theme_settings form.
 *
 * Attempts to validate normal system paths, paths relative to the public files
 * directory, or stream wrapper URIs. If the given path is any of the above,
 * returns a valid path or URI that the theme system can display.
 *
 * @param $path
 *   A path relative to the Drupal root or to the public files directory, or
 *   a stream wrapper URI.
 * @return mixed
 *   A valid path that can be displayed through the theme system, or FALSE if
 *   the path could not be validated.
 */
function _system_theme_settings_validate_path($path) {
  if (drupal_realpath($path)) {
    // The path is relative to the Drupal root, or is a valid URI.
    return $path;
  }
  $uri = 'public://' . $path;
  if (file_exists($uri)) {
    return $uri;
  }
  return FALSE;
}

/**
 * Process system_theme_settings form submissions.
 */
function system_theme_settings_submit($form, &$form_state) {
  $values = $form_state['values'];

  // If the user uploaded a new logo or favicon, save it to a permanent location
  // and use it in place of the default theme-provided file.
  if ($file = $values['logo_upload']) {
    unset($values['logo_upload']);
    $filename = file_unmanaged_copy($file->uri);
    $values['default_logo'] = 0;
    $values['logo_path'] = $filename;
    $values['toggle_logo'] = 1;
  }
  if ($file = $values['favicon_upload']) {
    unset($values['favicon_upload']);
    $filename = file_unmanaged_copy($file->uri);
    $values['default_favicon'] = 0;
    $values['favicon_path'] = $filename;
    $values['toggle_favicon'] = 1;
  }

  // If the user entered a path relative to the system files directory for
  // a logo or favicon, store a public:// URI so the theme system can handle it.
  if (!empty($values['logo_path'])) {
    $values['logo_path'] = _system_theme_settings_validate_path($values['logo_path']);
  }
  if (!empty($values['favicon_path'])) {
    $values['favicon_path'] = _system_theme_settings_validate_path($values['favicon_path']);
  }

  if (empty($values['default_favicon']) && !empty($values['favicon_path'])) {
    $values['favicon_mimetype'] = file_get_mimetype($values['favicon_path']);
  }
  $key = $values['var'];

  // Exclude unnecessary elements before saving.
  unset($values['var'], $values['submit'], $values['reset'], $values['form_id'], $values['op'], $values['form_build_id'], $values['form_token']);
  variable_set($key, $values);
  drupal_set_message(t('The configuration options have been saved.'));

  cache_clear_all();
}

/**
 * Recursively check compatibility.
 *
 * @param $incompatible
 *   An associative array which at the end of the check contains all
 *   incompatible files as the keys, their values being TRUE.
 * @param $files
 *   The set of files that will be tested.
 * @param $file
 *   The file at which the check starts.
 * @return
 *   Returns TRUE if an incompatible file is found, NULL (no return value)
 *   otherwise.
 */
function _system_is_incompatible(&$incompatible, $files, $file) {
  if (isset($incompatible[$file->name])) {
    return TRUE;
  }
  // Recursively traverse required modules, looking for incompatible modules.
  foreach ($file->requires as $requires) {
    if (isset($files[$requires]) && _system_is_incompatible($incompatible, $files, $files[$requires])) {
      $incompatible[$file->name] = TRUE;
      return TRUE;
    }
  }
}

/**
 * Menu callback; provides module enable/disable interface.
 *
 * The list of modules gets populated by module.info files, which contain each module's name,
 * description and information about which modules it requires.
 * @see drupal_parse_info_file for information on module.info descriptors.
 *
 * Dependency checking is performed to ensure that a module:
 * - can not be enabled if there are disabled modules it requires.
 * - can not be disabled if there are enabled modules which depend on it.
 *
 * @param $form_state
 *   An associative array containing the current state of the form.
 * @ingroup forms
 * @see theme_system_modules()
 * @see system_modules_submit()
 * @return
 *   The form array.
 */
function system_modules($form, $form_state = array()) {
  // Get current list of modules.
  $files = system_rebuild_module_data();

  // Remove hidden modules from display list.
  foreach ($files as $filename => $file) {
    if (!empty($file->info['hidden']) || !empty($file->info['required'])) {
      unset($files[$filename]);
    }
  }

  uasort($files, 'system_sort_modules_by_info_name');

  // If the modules form was submitted, then system_modules_submit() runs first
  // and if there are unfilled required modules, then $form_state['storage'] is
  // filled, triggering a rebuild. In this case we need to display a
  // confirmation form.
  if (!empty($form_state['storage'])) {
    return system_modules_confirm_form($files, $form_state['storage']);
  }

  $modules = array();
  $form['modules'] = array('#tree' => TRUE);

  // Used when checking if module implements a help page.
  $help_arg = module_exists('help') ? drupal_help_arg() : FALSE;

  // Iterate through each of the modules.
  foreach ($files as $filename => $module) {
    $extra = array();
    $extra['enabled'] = (bool) $module->status;
    // If this module requires other modules, add them to the array.
    foreach ($module->requires as $requires => $v) {
      if (!isset($files[$requires])) {
        $extra['requires'][$requires] = t('@module (<span class="admin-missing">missing</span>)', array('@module' => drupal_ucfirst($requires)));
        $extra['disabled'] = TRUE;
      }
      else {
        $requires_name = $files[$requires]->info['name'];
        if ($incompatible_version = drupal_check_incompatibility($v, str_replace(DRUPAL_CORE_COMPATIBILITY . '-', '', $files[$requires]->info['version']))) {
          $extra['requires'][$requires] = t('@module (<span class="admin-missing">incompatible with</span> version @version)', array(
            '@module' => $requires_name . $incompatible_version,
            '@version' => $files[$requires]->info['version'],
          ));
          $extra['disabled'] = TRUE;
        }
        elseif ($files[$requires]->status) {
          $extra['requires'][$requires] = t('@module (<span class="admin-enabled">enabled</span>)', array('@module' => $requires_name));
        }
        else {
          $extra['requires'][$requires] = t('@module (<span class="admin-disabled">disabled</span>)', array('@module' => $requires_name));
        }
      }
    }
    // Generate link for module's help page, if there is one.
    if ($help_arg && $module->status && in_array($filename, module_implements('help'))) {
      if (module_invoke($filename, 'help', "admin/help#$filename", $help_arg)) {
        $extra['links']['help'] = array(
          '#type' => 'link',
          '#title' => t('Help'),
          '#href' => "admin/help/$filename",
          '#options' => array('attributes' => array('class' =>  array('module-link', 'module-link-help'), 'title' => t('Help'))),
        );
      }
    }
    // Generate link for module's permission, if the user has access to it.
    if ($module->status && user_access('administer permissions') && in_array($filename, module_implements('permission'))) {
      $extra['links']['permissions'] = array(
        '#type' => 'link',
        '#title' => t('Permissions'),
        '#href' => 'admin/config/people/permissions',
        '#options' => array('fragment' => 'module-' . $filename, 'attributes' => array('class' => array('module-link', 'module-link-permissions'), 'title' => t('Configure permissions'))),
      );
    }
    // Generate link for module's configuration page, if the module provides
    // one.
    if ($module->status && isset($module->info['configure'])) {
      $configure_link = menu_get_item($module->info['configure']);
      if ($configure_link['access']) {
        $extra['links']['configure'] = array(
          '#type' => 'link',
          '#title' => t('Configure'),
          '#href' => $configure_link['href'],
          '#options' => array('attributes' => array('class' => array('module-link', 'module-link-configure'), 'title' => $configure_link['description'])),
        );
      }
    }

    // Mark dependents disabled so the user cannot remove required modules.
    $dependents = array();
    // If this module is required by other modules, list those, and then make it
    // impossible to disable this one.
    foreach ($module->required_by as $required_by => $v) {
      // Hidden modules are unset already.
      if (isset($files[$required_by])) {
        if ($files[$required_by]->status == 1) {
          $extra['required_by'][] = t('@module (<span class="admin-enabled">enabled</span>)', array('@module' => $files[$required_by]->info['name']));
          $extra['disabled'] = TRUE;
        }
        else {
          $extra['required_by'][] = t('@module (<span class="admin-disabled">disabled</span>)', array('@module' => $files[$required_by]->info['name']));
        }
      }
    }
    $form['modules'][$module->info['package']][$filename] = _system_modules_build_row($module->info, $extra);
  }
  // Add basic information to the fieldsets.
  foreach (element_children($form['modules']) as $package) {
    $form['modules'][$package] += array(
      '#type' => 'fieldset',
      '#title' => t($package),
      '#collapsible' => TRUE,
      '#theme' => 'system_modules_fieldset',
      '#header' => array(
        array('data' => t('Enabled'), 'class' => array('checkbox')),
        t('Name'),
        t('Version'),
        t('Description'),
        array('data' => t('Operations'), 'colspan' => 3),
      ),
    );
  }

  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Save configuration'),
  );
  $form['#action'] = url('admin/config/modules/list/confirm');

  return $form;
}

/**
 * Array sorting callback; sorts modules or themes by their name.
 */
function system_sort_modules_by_info_name($a, $b) {
  return strcasecmp($a->info['name'], $b->info['name']);
}

/**
 * Array sorting callback; sorts modules or themes by their name.
 */
function system_sort_themes($a, $b) {
  if ($a->is_default) {
    return -1;
  }
  if ($b->is_default) {
    return 1;
  }
  return strcasecmp($a->info['name'], $b->info['name']);
}

/**
 * Build a table row for the system modules page.
 */
function _system_modules_build_row($info, $extra) {
  // Add in the defaults.
  $extra += array(
    'requires' => array(),
    'required_by' => array(),
    'disabled' => FALSE,
    'enabled' => FALSE,
    'links' => array(),
  );
  $form = array(
    '#tree' => TRUE,
  );
  // Set the basic properties.
  $form['name'] = array(
    '#markup' => $info['name'],
  );
  $form['description'] = array(
    '#markup' => t($info['description']),
  );
  $form['version'] = array(
    '#markup' => $info['version'],
  );