# document-gallery/3.0.2/admin/class-admin.php

Document Gallery, version 3.0.2. 1,234 lines.

- Page: https://pluginprobe.com/plugins/document-gallery/3.0.2/code/admin/class-admin.php
- Raw: https://pluginprobe.com/plugins/document-gallery/3.0.2/raw/admin/class-admin.php
- Modified: 2015-03-05T00:06:12+00:00

Line numbers below start at 1. Link to a line or a range by appending a fragment to the
page URL, for example `https://pluginprobe.com/plugins/document-gallery/3.0.2/code/admin/class-admin.php#L10-L20`.

```php
<?php
defined('WPINC') OR exit;

class DG_Admin {
   /**
    * @var string The hook for the Document Gallery settings page.
    */
   private static $hook;

   /**
    * @var string The current tab being rendered.
    */
   private static $current;

   /**
    * NOTE: This should only ever be accessed through getTabs().
    * 
    * @var multitype:string Associative array containing all tab names, keyed by tab slug.
    */
   private static $tabs;

   /**
    * Returns reference to tabs array, initializing if needed.
    * 
    * NOTE: This cannot be done in a static constructor due to timing with i18n.
    */
   public static function &getTabs() {
      if (!isset(self::$tabs)) {
         self::$tabs = array(
            'General'    => __('General',                'document-gallery'),
            'Thumbnail'  => __('Thumbnail Management',   'document-gallery'),
            'Logging'    => __('Logging',                'document-gallery'),
            'Advanced'   => __('Advanced',               'document-gallery'));
      }

      return self::$tabs;
   }

   /**
    * Renders Document Gallery options page.
    */
   public static function renderOptions() { ?>
<div class="wrap">
   <h2><?php echo __('Document Gallery Settings', 'document-gallery'); ?></h2>

   <h2 class="nav-tab-wrapper">
<?php foreach (self::getTabs() as $tab => $name) {
   $class = ($tab == self::$current) ? ' nav-tab-active' : '';
   echo '<a class="nav-tab '.$tab.'-tab'.$class.'" href="?page=' . DG_OPTION_NAME . '&tab='.$tab.'">'.$name.'</a>';
} ?>
</h2>

   <form method="post" action="options.php" id="tab-<?php echo self::$current?>">
      <input type="hidden" name="<?php echo DG_OPTION_NAME; ?>[tab]" value="<?php echo self::$current; ?>" />
<?php
   settings_fields(DG_OPTION_NAME);
   do_settings_sections(DG_OPTION_NAME);
   if (self::$current != 'Thumbnail' && self::$current != 'Logging') {
      submit_button();
   }
?>
</form>

</div>
<?php }

   /**
    * Adds settings link to main plugin view.
    */
   public static function addSettingsLink($links) {
      $settings = '<a href="options-general.php?page=' . DG_OPTION_NAME . '">' .
          __('Settings', 'document-gallery') . '</a>';
      array_unshift($links, $settings);
      
      return $links;
   }

   /**
    * Adds donate link to main plugin view.
    */
   public static function addDonateLink($links, $file) {
      if ($file === DG_BASENAME) {
         global $dg_options;

         $donate = '<strong><a href="' . $dg_options['meta']['donate_link'] . '">' .
               __('Donate', 'document-gallery') . '</a></strong>';
         $links[] = $donate;
      }

      return $links;
   }

   /**
    * Adds Document Gallery settings page to admin navigation.
    */
   public static function addAdminPage() {
      DG_Admin::$hook = add_options_page(
          __('Document Gallery Settings', 'document-gallery'),
          __('Document Gallery', 'document-gallery'),
          'manage_options', DG_OPTION_NAME, array(__CLASS__, 'renderOptions'));
      add_action('admin_enqueue_scripts', array(__CLASS__, 'enqueueScriptsAndStyles'));
   }

   /**
    * Enqueues styles and scripts for the admin settings page.
    */
   public static function enqueueScriptsAndStyles($hook) {
      if ($hook !== DG_Admin::$hook) return;

      wp_enqueue_style('document-gallery-admin', DG_URL . 'assets/css/admin.css', null, DG_VERSION);
      wp_enqueue_script('document-gallery-admin', DG_URL . 'assets/js/admin.js', array('jquery'), DG_VERSION, true);
      wp_localize_script('document-gallery-admin', 'dg_admin_vars', array('upload_limit' => wp_max_upload_size()));
      if ($hook == 'post.php') {
         wp_localize_script('document-gallery-admin', 'ajax_object', array('ajax_url' => admin_url('admin-ajax.php')));
      }
   }

   /**
    * Registers settings for the Document Gallery options page.
    */
   public static function registerSettings() {
      if (empty($_REQUEST['tab']) || !array_key_exists($_REQUEST['tab'], self::getTabs())) {
         reset(self::getTabs());
         self::$current = key(self::getTabs());
      } else {
         self::$current = $_REQUEST['tab'];
      }

      register_setting(DG_OPTION_NAME, DG_OPTION_NAME, array(__CLASS__, 'validateSettings'));
      
      $funct = 'register' . self::$current . 'Settings';
      DG_Admin::$funct();
   }

   /**
    * Registers settings for the general tab.
    */
   private static function registerGeneralSettings() {
      global $dg_options;

      include_once DG_PATH . 'inc/class-gallery.php';
      include_once DG_PATH . 'inc/class-thumber.php';

      $defaults = $dg_options['gallery'];
      $active = $dg_options['thumber']['active'];

      add_settings_section(
        'gallery_defaults', __('Default Settings', 'document-gallery'),
        array(__CLASS__, 'renderDefaultSettingsSection'), DG_OPTION_NAME);

      add_settings_section(
        'thumbnail_generation', __('Thumbnail Generation', 'document-gallery'),
        array(__CLASS__, 'renderThumberSection'), DG_OPTION_NAME);

      add_settings_section(
          'css', __('Custom CSS', 'document-gallery'),
          array(__CLASS__, 'renderCssSection'), DG_OPTION_NAME);

      add_settings_field(
        'gallery_defaults_attachment_pg', 'attachment_pg',
        array(__CLASS__, 'renderCheckboxField'),
        DG_OPTION_NAME, 'gallery_defaults',
        array (
            'label_for'   => 'label_gallery_defaults_attachment_pg',
            'name'        => 'gallery_defaults][attachment_pg',
            'value'       => esc_attr($defaults['attachment_pg']),
            'option_name' => DG_OPTION_NAME,
            'description' => __('Link to attachment page rather than to file', 'document-gallery')
        ));

      add_settings_field(
         'gallery_defaults_columns', 'columns',
         array(__CLASS__, 'renderTextField'),
         DG_OPTION_NAME, 'gallery_defaults',
         array (
            'label_for'   => 'label_gallery_defaults_columns',
            'name'        => 'gallery_defaults][columns',
            'value'       => esc_attr($defaults['columns']),
            'type'        => 'number" min="1" step="1',
            'option_name' => DG_OPTION_NAME,
            'description' => __('The number of columns to display when not rendering descriptions.', 'document-gallery')
         ));

      add_settings_field(
        'gallery_defaults_descriptions', 'descriptions',
        array(__CLASS__, 'renderCheckboxField'),
        DG_OPTION_NAME, 'gallery_defaults',
        array (
            'label_for'   => 'label_gallery_defaults_descriptions',
            'name'        => 'gallery_defaults][descriptions',
            'value'       => esc_attr($defaults['descriptions']),
            'option_name' => DG_OPTION_NAME,
            'description' => __('Include document descriptions', 'document-gallery')
        ));

      add_settings_field(
        'gallery_defaults_fancy', 'fancy',
        array(__CLASS__, 'renderCheckboxField'),
        DG_OPTION_NAME, 'gallery_defaults',
        array (
            'label_for'   => 'label_gallery_defaults_fancy',
            'name'        => 'gallery_defaults][fancy',
            'value'       => esc_attr($defaults['fancy']),
            'option_name' => DG_OPTION_NAME,
            'description' => __('Use auto-generated document thumbnails', 'document-gallery')
        ));

      add_settings_field(
        'gallery_defaults_order', 'order',
        array(__CLASS__, 'renderSelectField'),
        DG_OPTION_NAME, 'gallery_defaults',
        array (
            'label_for'   => 'label_gallery_defaults_order',
            'name'        => 'gallery_defaults][order',
            'value'       => esc_attr($defaults['order']),
            'options'     => DG_Gallery::getOrderOptions(),
            'option_name' => DG_OPTION_NAME,
            'description' => __('Ascending or descending sorting of documents', 'document-gallery')
        ));

      add_settings_field(
        'gallery_defaults_orderby', 'orderby',
        array(__CLASS__, 'renderSelectField'),
        DG_OPTION_NAME, 'gallery_defaults',
        array (
            'label_for'   => 'label_gallery_defaults_orderby',
            'name'        => 'gallery_defaults][orderby',
            'value'       => esc_attr($defaults['orderby']),
            'options'     => DG_Gallery::getOrderbyOptions(),
            'option_name' => DG_OPTION_NAME,
            'description' => __('Which field to order documents by', 'document-gallery')
        ));

      add_settings_field(
        'gallery_defaults_relation', 'relation',
        array(__CLASS__, 'renderSelectField'),
        DG_OPTION_NAME, 'gallery_defaults',
        array (
            'label_for'   => 'label_gallery_defaults_relation',
            'name'        => 'gallery_defaults][relation',
            'value'       => esc_attr($defaults['relation']),
            'options'     => DG_Gallery::getRelationOptions(),
            'option_name' => DG_OPTION_NAME,
            'description' => __('Whether matched documents must have all taxa_names (AND) or at least one (OR)', 'document-gallery')
        ));

      add_settings_field(
         'gallery_defaults_limit', 'limit',
         array(__CLASS__, 'renderTextField'),
         DG_OPTION_NAME, 'gallery_defaults',
         array (
            'label_for'   => 'label_gallery_defaults_limit',
            'name'        => 'gallery_defaults][limit',
            'value'       => esc_attr($defaults['limit']),
            'type'        => 'number" min="-1" step="1',
            'option_name' => DG_OPTION_NAME,
            'description' => __('Limit the number of documents included. -1 means no limit.', 'document-gallery')
         ));

      add_settings_field(
         'gallery_defaults_mime_types', 'mime_types',
         array(__CLASS__, 'renderTextField'),
         DG_OPTION_NAME, 'gallery_defaults',
         array (
            'label_for'   => 'label_gallery_defaults_mime_types',
            'name'        => 'gallery_defaults][mime_types',
            'value'       => esc_attr($defaults['mime_types']),
            'type'        => 'text',
            'option_name' => DG_OPTION_NAME,
            'description' => __('Comma-delimited list of <a href="http://en.wikipedia.org/wiki/Internet_media_type#List_of_common_media_types">MIME types</a>.', 'document-gallery')
         ));
      
      add_settings_field(
        'gallery_defaults_post_status', 'post_status',
        array(__CLASS__, 'renderSelectField'),
        DG_OPTION_NAME, 'gallery_defaults',
        array (
            'label_for'   => 'label_gallery_defaults_post_status',
            'name'        => 'gallery_defaults][post_status',
            'value'       => esc_attr($defaults['post_status']),
            'options'     => DG_Gallery::getPostStatuses(),
            'option_name' => DG_OPTION_NAME,
            'description' => __('Which post status to look for when querying documents.', 'document-gallery')
        ));

      add_settings_field(
        'gallery_defaults_post_type', 'post_type',
        array(__CLASS__, 'renderSelectField'),
        DG_OPTION_NAME, 'gallery_defaults',
        array (
            'label_for'   => 'label_gallery_defaults_post_type',
            'name'        => 'gallery_defaults][post_type',
            'value'       => esc_attr($defaults['post_type']),
            'options'     => DG_Gallery::getPostTypes(),
            'option_name' => DG_OPTION_NAME,
            'description' => __('Which post type to look for when querying documents.', 'document-gallery')
        ));

      add_settings_field(
        'thumbnail_generation_av', 'Audio/Video',
        array(__CLASS__, 'renderCheckboxField'),
        DG_OPTION_NAME, 'thumbnail_generation',
        array (
            'label_for'   => 'label_thumbnail_generation_av',
            'name'        => 'thumbnail_generation][av',
            'value'       => esc_attr($active['av']),
            'option_name' => DG_OPTION_NAME,
            'description' => esc_html__('Locally generate thumbnails for audio & video files.', 'document-gallery')
        ));

      add_settings_field(
        'thumbnail_generation_gs', 'Ghostscript',
        array(__CLASS__, 'renderCheckboxField'),
        DG_OPTION_NAME, 'thumbnail_generation',
        array (
            'label_for'   => 'label_thumbnail_generation_gs',
            'name'        => 'thumbnail_generation][gs',
            'value'       => esc_attr($active['gs']),
            'option_name' => DG_OPTION_NAME,
            'description' => DG_Thumber::isGhostscriptAvailable()
                              ? __('Use <a href="http://www.ghostscript.com/" target="_blank">Ghostscript</a> for faster local PDF processing (compared to Imagick).', 'document-gallery')
                              : __('Your server is not configured to run <a href="http://www.ghostscript.com/" target="_blank">Ghostscript</a>.', 'document-gallery'),
            'disabled'    => !DG_Thumber::isGhostscriptAvailable()
        ));

      add_settings_field(
        'thumbnail_generation_imagick', 'Imagick',
        array(__CLASS__, 'renderCheckboxField'),
        DG_OPTION_NAME, 'thumbnail_generation',
        array (
            'label_for'   => 'label_thumbnail_generation_imagick',
            'name'        => 'thumbnail_generation][imagick',
            'value'       => esc_attr($active['imagick']),
            'option_name' => DG_OPTION_NAME,
            'description' => DG_Thumber::isImagickAvailable()
                              ? __('Use <a href="http://www.php.net/manual/en/book.imagick.php" target="_blank">Imagick</a> to handle lots of filetypes locally.', 'document-gallery')
                              : __('Your server is not configured to run <a href="http://www.php.net/manual/en/book.imagick.php" target="_blank">Imagick</a>.', 'document-gallery'),
            'disabled'    => !DG_Thumber::isImagickAvailable()
        ));

      add_settings_field(
         'thumbnail_generation_width', 'Max Thumbnail Dimensions',
         array(__CLASS__, 'renderMultiTextField'),
         DG_OPTION_NAME, 'thumbnail_generation',
         array (
            array (
               'label_for'   => 'label_advanced_width',
               'name'        => 'thumbnail_generation][width',
               'value'       => esc_attr($dg_options['thumber']['width']),
               'type'        => 'number" min="1" step="1',
               'option_name' => DG_OPTION_NAME,
               'description' => ' x '),
            array (
               'label_for'   => 'label_advanced_height',
               'name'        => 'thumbnail_generation][height',
               'value'       => esc_attr($dg_options['thumber']['height']),
               'type'        => 'number" min="1" step="1',
               'option_name' => DG_OPTION_NAME,
               'description' => __('The max width and height (in pixels) that thumbnails will be generated.', 'document-gallery'))
         ));
   }

   /**
    * Registers settings for the thumbnail management tab.
    */
   private static function registerThumbnailSettings() {
      add_settings_section(
          'thumbnail_table', '',
         array(__CLASS__, 'renderThumbnailSection'), DG_OPTION_NAME);
   }

   /**
    * Registers settings for the logging tab.
    */
   private static function registerLoggingSettings() {
      add_settings_section(
          'logging_table', '',
         array(__CLASS__, 'renderLoggingSection'), DG_OPTION_NAME);
   }

   /**
    * Registers settings for the advanced tab.
    */
   private static function registerAdvancedSettings() {
      global $dg_options;

      add_settings_section(
         'advanced', __('Advanced Thumbnail Generation', 'document-gallery'),
         array(__CLASS__, 'renderAdvancedSection'), DG_OPTION_NAME);

      add_settings_field(
         'advanced_logging', 'Logging',
         array(__CLASS__, 'renderCheckboxField'),
         DG_OPTION_NAME, 'advanced',
         array (
            'label_for'   => 'label_advanced_logging',
            'name'        => 'logging',
            'value'       => esc_attr($dg_options['logging']),
            'option_name' => DG_OPTION_NAME,
            'description' => __('Whether to log debug and error information related to Document Gallery.', 'document-gallery')
         ));

      add_settings_field(
         'advanced_validation', 'Option Validation',
         array(__CLASS__, 'renderCheckboxField'),
         DG_OPTION_NAME, 'advanced',
         array (
            'label_for'   => 'label_advanced_validation',
            'name'        => 'validation',
            'value'       => esc_attr($dg_options['validation']),
            'option_name' => DG_OPTION_NAME,
            'description' => __('Whether option structure should be validated before save. This is not generally necessary.', 'document-gallery')
         ));

      add_settings_field(
         'advanced_thumb_timeout', 'Thumbnail Generation Timeout',
         array(__CLASS__, 'renderTextField'),
         DG_OPTION_NAME, 'advanced',
         array (
            'label_for'   => 'label_advanced_thumb_timeout',
            'name'        => 'timeout',
            'value'       => esc_attr($dg_options['thumber']['timeout']),
            'type'        => 'number" min="1" step="1',
            'option_name' => DG_OPTION_NAME,
            'description' => __('Max number of seconds to wait for thumbnail generation before defaulting to filetype icons.', 'document-gallery') .
                             ' <em>' . __('Note that generation will continue where timeout happened next time the gallery is loaded.', 'document-gallery') . '</em>'));

      add_settings_field(
        'advanced_gs', 'Ghostscript Absolute Path',
        array(__CLASS__, 'renderTextField'),
        DG_OPTION_NAME, 'advanced',
        array (
            'label_for'   => 'label_advanced_gs',
            'name'        => 'gs',
            'value'       => esc_attr($dg_options['thumber']['gs']),
            'option_name' => DG_OPTION_NAME,
            'description' => $dg_options['thumber']['gs']
               ? __('Successfully auto-detected the location of Ghostscript.', 'document-gallery')
               : __('Failed to auto-detect the location of Ghostscript.', 'document-gallery')
        ));

      add_settings_section(
         'advanced_options_dump', __('Options Array Dump', 'document-gallery'),
         array(__CLASS__, 'renderOptionsDumpSection'), DG_OPTION_NAME);
   }

   /**
    * Validates submitted options, sanitizing any invalid options.
    * @param array $values User-submitted new options.
    * @return array Sanitized new options.
    */
   public static function validateSettings($values) {
      if (empty($values['tab']) || !array_key_exists($values['tab'], self::getTabs())) {
         reset(self::getTabs());
         $values['tab'] = key(self::getTabs());
      }
      $funct = 'validate'.$values['tab'].'Settings';
      unset($values['tab']);
      return DG_Admin::$funct($values);
   }

   /**
    * Validates general settings, sanitizing any invalid options.
    * @param array $values User-submitted new options.
    * @return array Sanitized new options.
    */
   private static function validateGeneralSettings($values) {
      global $dg_options;
      $ret = $dg_options;
      
      include_once DG_PATH . 'inc/class-gallery.php';
      
      $thumbs_cleared = false;

      // handle gallery shortcode defaults
      $errs = array();
      $ret['gallery'] = DG_Gallery::sanitizeDefaults(null, $values['gallery_defaults'], $errs);

      foreach ($errs as $k => $v) {
         add_settings_error(DG_OPTION_NAME, str_replace('_', '-', $k), $v);
      }

      // handle setting width
      if (isset($values['thumbnail_generation']['width'])) {
         $width = (int)$values['thumbnail_generation']['width'];
         if ($width > 0) {
            $ret['thumber']['width'] = $width;
         } else {
            add_settings_error(DG_OPTION_NAME, 'thumber-width',
               __('Invalid width given: ', 'document-gallery') . $values['thumbnail_generation']['width']);
         }
         
         unset($values['thumbnail_generation']['width']);
      }

      // handle setting height
      if (isset($values['thumbnail_generation']['height'])) {
         $height = (int)$values['thumbnail_generation']['height'];
         if ($height > 0) {
            $ret['thumber']['height'] = $height;
         } else {
            add_settings_error(DG_OPTION_NAME, 'thumber-height',
               __('Invalid height given: ', 'document-gallery') . $values['thumbnail_generation']['height']);
         }
         
         unset($values['thumbnail_generation']['width']);
      }

      // delete thumb cache to force regeneration if max dimensions changed
      if ($ret['thumber']['width'] !== $dg_options['thumber']['width'] ||
         $ret['thumber']['height'] !== $dg_options['thumber']['height']) {
         foreach ($ret['thumber']['thumbs'] as $v) {
            if (isset($v['thumber'])) {
               @unlink($v['thumb_path']);
            }
         }

         $ret['thumber']['thumbs'] = array();
         $thumbs_cleared = true;
      }

      // handle setting the active thumbers
      foreach (array_keys($ret['thumber']['active']) as $k) {
         $ret['thumber']['active'][$k] = isset($values['thumbnail_generation'][$k]);
      }

      // if new thumbers available, clear failed thumbnails for retry
      if (!$thumbs_cleared) {
         foreach ($dg_options['thumber']['active'] as $k => $v) {
            if (!$v && $ret['thumber']['active'][$k]) {
               foreach ($dg_options['thumber']['thumbs'] as $k => $v) {
                  if (empty($v['thumber'])) {
                     unset($ret['thumber']['thumbs'][$k]);
                  }
               }
               break;
            }
         }
      }

      // handle modified CSS
      if (trim($ret['css']['text']) !== trim($values['css'])) {
         $ret['css']['text'] = trim($values['css']);
         $ret['css']['minified'] = DocumentGallery::compileCustomCss($ret['css']['text']);
      }

      return $ret;
   }

   /**
    * Validates thumbnail management settings, sanitizing any invalid options.
    * @param array $values User-submitted new options.
    * @return array Sanitized new options.
    */
   private static function validateThumbnailSettings($values) {
      global $dg_options;
      $ret = $dg_options;
      $responseArr = array('result' => false);

      if (isset($values['entry'])) {
         $ID = intval($values['entry']);
      } else {
         $ID = -1;
      }

      // Thumbnail(s) cleanup;
      // cleanup value is a marker
      if ( isset($values['cleanup']) && isset($values['ids']) ) {
         $deleted = array_values(array_intersect(array_keys($dg_options['thumber']['thumbs']), $values['ids']));

         foreach ($deleted as $k) {
            if (isset($ret['thumber']['thumbs'][$k]['thumber'])) {
               @unlink($ret['thumber']['thumbs'][$k]['thumb_path']);
            }

            unset($ret['thumber']['thumbs'][$k]);
         }

         $responseArr['result'] = true;
         $responseArr['deleted'] = $deleted;
      }
      
      // Attachment title update
      // title value is a marker
      elseif ( isset($values['title']) && $ID != -1 ) {
         $attachment = array(
            'ID'         => $ID,
            'post_title' => rawurldecode(addslashes($values['title']))
         );
         if ( wp_update_post( $attachment ) ) {
            $responseArr['result'] = true;
         }
      }
      
      // Attachment description update
      // description value is a marker
      elseif ( isset($values['description']) && $ID != -1 ) {
         $attachment = array(
            'ID'           => $ID,
            'post_content' => rawurldecode(addslashes($values['description']))
         );
         if ( wp_update_post( $attachment ) ) {
            $responseArr['result'] = true;
         }
      }
      
      // Thumbnail file manual refresh (one at a time)
      // upload value is a marker
      elseif ( isset($values['upload']) && isset($_FILES['file']) && isset($ret['thumber']['thumbs'][$ID]) ) {
         $old_path = $ret['thumber']['thumbs'][$ID]['thumb_path'];
         $uploaded_filename = self::validateUploadedFile();
         if ($uploaded_filename && DG_Thumber::setThumbnail($ID, $uploaded_filename)) {
            if ($dg_options['thumber']['thumbs'][$ID]['thumb_path'] !== $old_path) {
               @unlink($old_path);
            }
            $responseArr['result'] = true;
            $responseArr['url'] = $dg_options['thumber']['thumbs'][$ID]['thumb_url'];
            $ret['thumber']['thumbs'][$ID] = $dg_options['thumber']['thumbs'][$ID];
         }
      }

      if (isset($values['ajax'])) {
         echo DG_Util::jsonEncode($responseArr);
         add_filter('wp_redirect', array(__CLASS__, '_exit'), 1, 0);
      }

      return $ret;
   }

   /**
    * Validates uploaded file as a semi for potential thumbnail.
    * @param  str $var   File field name.
    * @return bool|str   False on failure, path to temp file on success.
    */
   public static function validateUploadedFile($var = 'file') {
      // checking if any file was delivered
      if (!isset($_FILES[$var]))
         return false;
      // we gonna process only first one
      if ( !is_array($_FILES[$var]['error']) ) {
         $upload_err  = $_FILES[$var]['error'];
         $upload_path = $_FILES[$var]['tmp_name'];
         $upload_size = $_FILES[$var]['size'];
         $upload_type = $_FILES[$var]['type'];
         $upload_name = $_FILES[$var]['name'];
      } else {
         $upload_err  = $_FILES[$var]['error'][0];
         $upload_path = $_FILES[$var]['tmp_name'][0];
         $upload_size = $_FILES[$var]['size'][0];
         $upload_type = $_FILES[$var]['type'][0];
         $upload_name = $_FILES[$var]['name'][0];
      }
      $info = getimagesize($upload_path);
      if ($info) {
         if ($info['mime']!=$upload_type) {// in DG_Thumber::getExt() we'll define and set appropriate extension
            DG_Logger::writeLog(
               DG_LogLevel::Warning,
               __('File extension doesn\'t match the MIME type of the image: ', 'document-gallery') .
               $upload_name.' - '.$info['mime']);
         }
         if ($upload_size>wp_max_upload_size()) {
            DG_Logger::writeLog(
               DG_LogLevel::Warning,
               __('Uploaded file size exceeds the allowable limit: ', 'document-gallery') .
               $upload_name.' - '.$upload_size.'b');
            return false;
         }
      } else {
         DG_Logger::writeLog(
            DG_LogLevel::Warning,
            __('Uploaded file is not an image: ', 'document-gallery') .
            $upload_name);
         return false;
      }
      if ($upload_err == UPLOAD_ERR_OK && $upload_size > 0) {
         $temp_file = $upload_path;
      } else {
         DG_Logger::writeLog(
            DG_LogLevel::Error,
            __('Failed to get uploaded file: ', 'document-gallery') .
            $upload_err);
         return false;
      }

      return $temp_file;
   }

   /**
    * Validates logging settings, sanitizing any invalid options.
    * @param array $values User-submitted new options.
    * @return array Sanitized new options.
    */
   private static function validateLoggingSettings($values) {
      global $dg_options;
      if (isset($values['clearLog'])) {
         DG_Logger::clearLog();
      }
      return $dg_options;
   }

   /**
    * Validates advanced settings, sanitizing any invalid options.
    * @param array $values User-submitted new options.
    * @return array Sanitized new options.
    */
   private static function validateAdvancedSettings($values) {
      global $dg_options;
      $ret = $dg_options;

      // handle setting the Ghostscript path
      if (isset($values['gs']) &&
         0 != strcmp($values['gs'], $ret['thumber']['gs'])) {
         if (false === strpos($values['gs'], ';')) {
            $ret['thumber']['gs'] = $values['gs'];
         } else {
            add_settings_error(DG_OPTION_NAME, 'thumber-gs',
               __('Invalid Ghostscript path given: ', 'document-gallery') . $values['gs']);
         }
      }

      // handle setting timeout
      if (isset($values['timeout'])) {
         $timeout = (int)$values['timeout'];
         if ($timeout > 0) {
            $ret['thumber']['timeout'] = $timeout;
         } else {
            add_settings_error(DG_OPTION_NAME, 'thumber-timeout',
               __('Invalid timeout given: ', 'document-gallery') . $values['timeout']);
         }
      }

      // validation checkbox
      $ret['validation'] = isset($values['validation']);
      
      // logging checkbox
      $ret['logging'] = isset($values['logging']);
      
      return $ret;
   }

   /**
    * @return bool Whether to register settings.
    */
   public static function doRegisterSettings() {
      if (!is_multisite()) {
         $script = !empty($GLOBALS['pagenow']) ? $GLOBALS['pagenow'] : null;
      } else {
         $script = parse_url($_SERVER['REQUEST_URI']);
         $script = basename($script['path']);
      }
      
      return !empty($script) && ('options-general.php' === $script || 'options.php' === $script);
   }

   /**
    * Render the Default Settings section.
    */
   public static function renderDefaultSettingsSection() { ?>
<p><?php _e('The following values will be used by default in the shortcode. You can still manually set each of these values in each individual shortcode.', 'document-gallery'); ?></p>
<?php }

   /**
    * Render the Thumber section.
    */
   public static function renderThumberSection() { ?>
<p><?php _e('Select which tools to use when generating thumbnails.', 'document-gallery'); ?></p>
<?php }

   /**
    * Renders a text field for use when modifying the CSS to be printed in addition to the default CSS.
    */
   public static function renderCssSection() {
      global $dg_options; ?>
<p><?php printf(
          __('Enter custom CSS styling for use with document galleries. To see which ids and classes you can style, take a look at <a href="%s" target="_blank">style.css</a>.'),
          DG_URL . 'assets/css/style.css'); ?></p>
<table class="form-table">
   <tbody>
      <tr valign="top">
         <td>
            <textarea name="<?php echo DG_OPTION_NAME; ?>[css]" rows="10" cols="50" class="large-text code"><?php echo $dg_options['css']['text']; ?></textarea>
         </td>
      </tr>
   </tbody>
</table>
<?php }

   /**
    * Render the Thumber Advanced section.
    */
   public static function renderAdvancedSection() {
      include_once DG_PATH . 'inc/class-thumber.php';?>
<p><?php _e('Unless you <em>really</em> know what you\'re doing, you should not touch these values.', 'document-gallery'); ?></p>
<?php if (!DG_Thumber::isExecAvailable()) : ?>
<p>
   <em><?php _e('NOTE: <code>exec()</code> is not accessible. Ghostscript will not function.', 'document-gallery'); ?></em>
</p>
<?php endif; ?>
   <?php }

   /**
    * Renders a readonly textfield containing a dump of current DG options.
    */
   public static function renderOptionsDumpSection() {
         global $dg_options; ?>
   <p><?php
      _e('The following <em>readonly text</em> should be provided when <a href="http://wordpress.org/support/plugin/document-gallery" target="_blank">reporting a bug</a>:', 'documet-gallery');
   ?></p>
   <table class="form-table">
      <tbody>
         <tr valign="top">
            <td>
               <textarea readonly="true" rows="10" cols="50" id="options-dump" class="large-text code"><?php print_r($dg_options); ?></textarea>
            </td>
         </tr>
      </tbody>
   </table>
   <?php }

   /**
    * Render the Thumbnail table.
    */
   public static function renderThumbnailSection() {
      include_once DG_PATH . 'inc/class-thumber.php';
      $options = DG_Thumber::getOptions();

      $URL_params = array('page' => DG_OPTION_NAME, 'tab' => 'Thumbnail');
      $att_ids = array();

      if (isset($_REQUEST['orderby']) && in_array(strtolower($_REQUEST['orderby']), array('title', 'date'))) {
         $orderby = strtolower($_REQUEST['orderby']);
         $URL_params['orderby'] = $orderby;

         switch ($orderby) {
            case 'date':
               foreach ($options['thumbs'] as $key => $node) {
                  $keyArray[$key] = $node['timestamp'];
                  $options['thumbs'][$key]['thumb_id'] = $att_ids[] = $key;
               }
               break;

            case 'title':
               foreach ($options['thumbs'] as $key => $node) {
                  $keyArray[$key] = basename($node['thumb_path']);
                  $options['thumbs'][$key]['thumb_id'] = $att_ids[] = $key;
               }
               break;
         }

         $order = strtolower($_REQUEST['order']);
         if (!isset($_REQUEST['order']) || !in_array($order, array('asc', 'desc'))) {
            $order = 'asc';
         }
         $URL_params['order'] = $order;

         if ($order == 'asc') {
            array_multisort($keyArray, SORT_ASC, $options['thumbs']);
         } else {
            array_multisort($keyArray, SORT_DESC, $options['thumbs']);
         }
      } else {
         $orderby = '';
         foreach ($options['thumbs'] as $key => $node) {
            $options['thumbs'][$key]['thumb_id'] = $att_ids[] = $key;
         }
      }

      static $limit_options = array(10, 25, 75);
      if (!isset($_REQUEST['limit']) || !in_array(intval($_REQUEST['limit']), $limit_options)) {
         $limit = $limit_options[0];
      } else {
         $limit = intval($_REQUEST['limit']);
      }

      $URL_params['limit'] = $limit;
      $select_limit = '';
      foreach ($limit_options as $l_o) {
         $select_limit .= '<option value="'.$l_o.'"'.selected($limit, $l_o, false).'>'.$l_o.'</option>'.PHP_EOL;
      }
      $thumbs_number = count($options['thumbs']);
      $lastsheet = ceil($thumbs_number/$limit);
      $sheet = isset($_REQUEST['sheet']) ? intval($_REQUEST['sheet']) : 1;
      if ($sheet <= 0 || $sheet > $lastsheet) {
         $sheet = 1;
      }

      $offset = ($sheet - 1) * $limit;

      $att_ids = array_slice($att_ids, $offset, $limit);
      
      // https://core.trac.wordpress.org/ticket/12212
	  $atts = array();
	  if (!empty($att_ids)) {
		  $atts = get_posts(
			 array(
				'post_type'   => 'any',
				'post_status' => 'any',
				'numberposts' => -1,
				'post__in'    => $att_ids,
				'orderby'     => 'post__in'
		  ));
	  }
	  
      $titles = array();
      $contents = array();
      foreach ($atts as $att) {
         $path_parts = pathinfo($att->guid);
         $titles[$att->ID] = $att->post_title;
         $types[$att->ID] = $path_parts['extension'];
         $contents[$att->ID] = $att->post_content;
      }
      unset($atts);

      $thead = '<tr>'.
            '<th scope="col" class="manage-column column-cb check-column">'.
               '<label class="screen-reader-text" for="cb-select-all-%1$d">'.__('Select All', 'document-gallery').'</label>'.
               '<input id="cb-select-all-%1$d" type="checkbox">'.
            '</th>'.
            '<th scope="col" class="manage-column column-icon">'.__('Thumbnail', 'document-gallery').'</th>'.
            '<th scope="col" class="manage-column column-title '.(($orderby != 'title')?'sortable desc':'sorted '.$order).'"><a href="?'.http_build_query(array_merge($URL_params, array('orderby'=>'title','order'=>(($orderby != 'title')?'asc':(($order == 'asc')?'desc':'asc'))))).'"><span>'.__('File name', 'document-gallery').'</span><span class="sorting-indicator"></span></th>'.
            '<th scope="col" class="manage-column column-description">'.__('Description', 'document-gallery').'</th>'.
            '<th scope="col" class="manage-column column-thumbupload"></th>'.
            '<th scope="col" class="manage-column column-date '.(($orderby != 'date')?'sortable asc':'sorted '.$order).'"><a href="?'.http_build_query(array_merge($URL_params, array('orderby'=>'date','order'=>(($orderby != 'date')?'desc':(($order == 'asc')?'desc':'asc'))))).'"><span>'.__('Date', 'document-gallery').'</span><span class="sorting-indicator"></span></th>'.
         '</tr>';

      $pagination = '<div class="alignleft bulkactions"><button class="button action deleteSelected">'.__('Delete Selected', 'document-gallery').'</button></div><div class="tablenav-pages">'.
            '<span class="displaying-num">'.
            $thumbs_number.' '._n('item', 'items', $thumbs_number).
            '</span>'.($lastsheet>1?
            '<span class="pagination-links">'.
               '<a class="first-page'.( $sheet==1 ? ' disabled' : '').'" title="'.__('Go to the first page', 'document-gallery').'"'.( $sheet==1 ? '' : ' href="?'.http_build_query($URL_params).'"').'>«</a>'.
               '<a class="prev-page'.( $sheet==1 ? ' disabled' : '').'" title="'.__('Go to the previous page', 'document-gallery').'"'.( $sheet==1 ? '' : ' href="?'.http_build_query(array_merge($URL_params, array('sheet'=>$sheet-1))).'"').'>‹</a>'.
               '<span class="paging-input">'.
                  '<input class="current-page" title="'.__('Current page', 'document-gallery').'" type="text" name="paged" value="'.$sheet.'" size="'.strlen($sheet).'" maxlength="'.strlen($sheet).'"> '.__('of', 'document-gallery').' <span class="total-pages">'.$lastsheet.'</span></span>'.
               '<a class="next-page'.( $sheet==$lastsheet ? ' disabled' : '').'" title="'.__('Go to the next page', 'document-gallery').'"'.( $sheet==$lastsheet ? '' : ' href="?'.http_build_query(array_merge($URL_params, array('sheet'=>$sheet+1))).'"').'>›</a>'.
               '<a class="last-page'.( $sheet==$lastsheet ? ' disabled' : '').'" title="'.__('Go to the last page', 'document-gallery').'"'.( $sheet==$lastsheet ? '' : ' href="?'.http_build_query(array_merge($URL_params, array('sheet'=>$lastsheet))).'"').'>»</a>'.
            '</span>':' <b>|</b> ').
            '<span class="displaying-num"><select dir="rtl" class="limit_per_page">'.$select_limit.'</select> '.__('items per page', 'document-gallery').'</span>'.
         '</div>'.
         '<br class="clear" />';
      ?>

<script type="text/javascript">
   var URL_params = <?php echo DG_Util::jsonEncode($URL_params); ?>;
</script>
<div class="thumbs-list-wrapper">
   <div>
      <div class="tablenav top"><?php echo $pagination; ?></div>
      <table id="ThumbsTable" class="wp-list-table widefat fixed media"
         cellpadding="0" cellspacing="0">
         <thead>
               <?php printf($thead, 1); ?>
            </thead>
         <tfoot>
               <?php printf($thead, 2); ?>
            </tfoot>
         <tbody><?php
               $i = 0;
               foreach ($options['thumbs'] as $v) {
                  if ($i < $offset) { $i++; continue; }
                  if (++$i > $offset + $limit) { break; }

                  $icon = isset($v['thumb_url']) ? $v['thumb_url'] : DG_Thumber::getDefaultThumbnail($v['thumb_id']);
                  $title = isset($titles[$v['thumb_id']]) ? $titles[$v['thumb_id']] : '';
                  $type = $types[$v['thumb_id']];
                  $description = $contents[$v['thumb_id']];
                  $date = DocumentGallery::localDateTimeFromTimestamp($v['timestamp']);
                  
                  echo '<tr data-entry="'.$v['thumb_id'].'"><td scope="row" class="check-column"><input type="checkbox" class="cb-ids" name="' . DG_OPTION_NAME . '[ids][]" value="' .
                          $v['thumb_id'].'"></td><td class="column-icon media-icon"><img src="' .
                          $icon.'" />'.'</td><td class="title column-title">' .
                          ($title ? '<strong><a href="' . home_url('/?attachment_id='.$v['thumb_id']).'" target="_blank" title="'.__('View', 'document-gallery').' \'' .
                           $title.'\' '.__('attachment page', 'document-gallery').'"><span class="editable-title">'.$title.'</span> <sup>'.$type.'</sup></a></strong>' : __('Attachment not found', 'document-gallery')) .
                           '<span class="dashicons dashicons-edit"></span><span class="edit-controls"><span class="dashicons dashicons-yes"></span> <span class="dashicons dashicons-no"></span></span></td><td class="column-description"><div class="editable-description">'.$description.'</div><span class="dashicons dashicons-edit"></span><span class="edit-controls"><span class="dashicons dashicons-yes"></span> <span class="dashicons dashicons-no"></span></span>'.                           '</td><td class="column-thumbupload">' .
                              '<span class="manual-download">' .
                                 '<span class="dashicons dashicons-upload"></span>' .
                                 '<span class="html5dndmarker">Drop file here<span> or </span></span>' .
                                 '<span class="buttons-area">' .
                                    '<input id="upload-button'.$v['thumb_id'].'" type="file" />' .
                                    '<input id="trigger-button'.$v['thumb_id'].'" type="button" value="Select File" class="button" />' .
                                 '</span>' .
                              '</span>' .
                          '</td><td class="date column-date">'.$date.'</td></tr>'.PHP_EOL;
               } ?>
            </tbody>
      </table>
      <div class="tablenav bottom"><?php echo $pagination; ?></div>
   </div>
</div>
<?php }

   /**
    * Adds meta box to the attchements' edit pages.
    */
   public static function addMetaBox() {
      $screens = array( 'attachment' );
      foreach ( $screens as $screen ) {
         add_meta_box(
               DG_OPTION_NAME.'_gen_box',
               __( '<b>Thumbnail</b> for <i><b>Document Gallery</b></i>', 'document-gallery' ),
               array(__CLASS__, 'renderMetaBox'),
               $screen,
               'normal'
            );
      }
      DG_Admin::$hook = 'post.php';
      add_action('admin_enqueue_scripts', array(__CLASS__, 'enqueueScriptsAndStyles'));
   }

   /**
    * Render a Meta Box.
    */
   public static function renderMetaBox($post) {
      global $dg_options;
      wp_nonce_field( DG_OPTION_NAME.'_meta_box', DG_OPTION_NAME.'_meta_box_nonce' );
      $ID = $post->ID;
                  $icon = isset($dg_options['thumber']['thumbs'][$ID]['thumb_url']) ? $dg_options['thumber']['thumbs'][$ID]['thumb_url'] : DG_Thumber::getDefaultThumbnail($ID);

                  echo '<table id="ThumbsTable" class="wp-list-table widefat fixed media" cellpadding="0" cellspacing="0">'.
                     '<tbody><tr data-entry="'.$ID.'"><td class="column-icon media-icon"><img src="' .
                     $icon.'" />'.'</td><td class="column-thumbupload">' .
                        '<span class="manual-download">' .
                           '<span class="dashicons dashicons-upload"></span>' .
                           '<span class="html5dndmarker">Drop file here<span> or </span></span>' .
                           '<span class="buttons-area">' .
                              '<input id="upload-button'.$ID.'" type="file" />' .
                              '<input id="trigger-button'.$ID.'" type="button" value="Select File" class="button" />' .
                           '</span>' .
                        '</span>' .
                     '</td></tr></tbody></table>'.
                     (empty($dg_options['thumber']['thumbs'][$ID]) ? '<span class="dashicons dashicons-info"></span><span class="">Please note this attachment hasn&#39;t been used in any Document Gallery instance and so there is no autogenerated thumbnail, in the meantime default one is used instead.</span>' : '').PHP_EOL;
   }

   /**
    * Save a Meta Box.
    */
   public static function saveMetaBox($post_id) {
      // Check if our nonce is set.
      // Verify that the nonce is valid.
      // If this is an autosave, our form has not been submitted, so we don't want to do anything.
      if ( !isset($_POST[DG_OPTION_NAME.'_meta_box_nonce']) || !wp_verify_nonce($_POST[DG_OPTION_NAME.'_meta_box_nonce'], DG_OPTION_NAME.'_meta_box') || (defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE) ) {
         return;
      }
      
      global $dg_options;
      $responseArr = array('result' => false);
      if (isset($_POST[DG_OPTION_NAME]['entry'])) {
         $ID = intval($_POST[DG_OPTION_NAME]['entry']);
      } else {
         $ID = -1;
      }
      if ( isset($_POST[DG_OPTION_NAME]['upload']) && isset($_FILES['file']) && isset($dg_options['thumber']['thumbs'][$ID]) ) {
         $old_path = $dg_options['thumber']['thumbs'][$ID]['thumb_path'];
         $uploaded_filename = self::validateUploadedFile();
         if ($uploaded_filename && DG_Thumber::setThumbnail($ID, $uploaded_filename)) {
            if ($dg_options['thumber']['thumbs'][$ID]['thumb_path'] !== $old_path) {
               @unlink($old_path);
            }
            $responseArr['result'] = true;
            $responseArr['url'] = $dg_options['thumber']['thumbs'][$ID]['thumb_url'];
         }
      }
      if (isset($_POST[DG_OPTION_NAME]['ajax'])) {
         echo DG_Util::jsonEncode($responseArr);
         wp_die();
      }
   }

   /**
    * Render the Logging table.
    */
   public static function renderLoggingSection() {
      $log_list = DG_Logger::readLog();
      if ($log_list) {
         $levels = array_map(array(__CLASS__, 'getLogLabelSpan'), array_keys(DG_LogLevel::getLogLevels()));

         $thead = '<tr>'.
               '<th scope="col" class="manage-column column-date"><span>'.__('Date', 'document-gallery').'</span></th>'.
               '<th scope="col" class="manage-column column-level"><span>'.__('Level', 'document-gallery').'</span></th>'.
               '<th scope="col" class="manage-column column-message"><span>'.__('Message', 'document-gallery').'</span></th>'.
            '</tr>';

         ?>
<div class="log-list-wrapper">
   <div>
      <div class="tablenav top">
         <div class="alignleft bulkactions">
            <button class="action expandAll">
               <?php echo __('Expand All', 'document-gallery'); ?>
            </button>
            <button class="action collapseAll">
               <?php echo __('Collapse All', 'document-gallery'); ?>
            </button>
         </div>
         <div class="levelSelector">
            <input type="checkbox" id="allLevels" name="lswitch" value="all" checked />
            <label for="allLevels" class="allLevels">ALL</label>
            <?php
               foreach (array_keys(DG_LogLevel::getLogLevels()) as $k) { ?>
                  <?php
                     $lower = strtolower($k);
                     $upper = strtoupper($k);
                  ?>
                  <input type="checkbox" id="<?php echo $lower; ?>Level" name="lswitch" value="<?php echo $lower; ?>" checked />
                  <label for="<?php echo $lower; ?>Level" class="<?php echo $lower; ?>Level"><?php echo $upper; ?></label>
               <?php }
            ?>
         </div>
      </div>
      <table id="LogTable" class="wp-list-table widefat fixed media" cellpadding="0" cellspacing="0">
         <thead>
            <?php echo $thead; ?>
         </thead>
         <tfoot>
            <?php echo $thead; ?>
         </tfoot>
         <tbody><?php
            $i = 0;
            foreach ($log_list as $v) {
               $date = DocumentGallery::localDateTimeFromTimestamp($v[0]);
               
               // convert attachment names to links
               $v[2] = preg_replace('/[ ^](attachment #)(\d+)[., ]/i', ' <a href="' . home_url() . '/?attachment_id=\2" target="_blank">\1<strong>\2</strong></a> ', $v[2]);
               
               // bold the place where log entry was submitted
               $v[2] = preg_replace('/^(\(\w+::\w+\)) /', '<strong>\1</strong> ', $v[2]);
               
               // italicize any function references within log entry
               $v[2] = preg_replace('/(\(?\w+::\w+\)?)/m', '<i>\1</i>', $v[2]);

               echo '<tr><td class="date column-date" data-sort-value="'.$v[0].'"><span class="logLabel date">'.$date.'</span></td>' .
                  '<td class="column-level">'.$levels[$v[1]].'</td>' .
                  '<td class="column-entry">'.(empty($v[3]) ? '<pre>'.$v[2].'</pre>' : '<div class="expander" title="Click to Expand"><pre>'.$v[2].'</pre><div><span class="dashicons dashicons-arrow-down-alt2"></span></div></div><div class="spoiler-body"><pre>'.$v[3].'</pre></div>').'</td>' .
                  '</tr>'.PHP_EOL;
            } ?>
         </tbody>
      </table>
      <div class="tablenav bottom">
         <div class="alignright bulkactions">
            <button class="button action clearLog" name = '<?php echo DG_OPTION_NAME; ?>[clearLog]' value = 'true'>
               <?php echo __('Clear Log', 'document-gallery'); ?>
            </button>
         </div>
      </div>
   </div>
</div>
<?php } else {
         echo '<div class="noLog">'.__('There are no log entries at this time.', 'document-gallery').'<br />'.__('For Your information:', 'document-gallery').' <strong><i>'.__('Logging', 'document-gallery').'</i></strong> '.(DG_Logger::logEnabled()?'<span class="loggingON">'.__('is turned ON', 'document-gallery').'!</span>':'<span class="loggingOFF">'.__('is turned OFF', 'document-gallery').'!</span>').'</div>';
      }
   }

   /**
    * Takes label name and returns SPAN tag.
    * @param string $e label name.
    * @return string SPAN tag
    */
   private static function getLogLabelSpan($e) {
      return '<span class="logLabel ' . strtolower($e) . '">' . strtoupper($e) . '</span>';
   }
   
   /**
    * Render a checkbox field.
    * @param array $args
    */
   public static function renderCheckboxField($args) {
      $args['disabled'] = isset($args['disabled']) ? $args['disabled'] : false;
      printf('<label><input type="checkbox" value="1" name="%1$s[%2$s]" id="%3$s" %4$s %5$s/> %6$s</label>',
          $args['option_name'],
          $args['name'],
          $args['label_for'],
          checked($args['value'], 1, false),
          disabled($args['disabled'], true, false),
          $args['description']);
   }

   /**
    * Render a text field.
    * @param array $args
    */
   public static function renderTextField($args) {
      printf('<input type="%1$s" value="%2$s" name="%3$s[%4$s]" id="%5$s" /> %6$s',
         isset($args['type']) ? $args['type'] : 'text',
         $args['value'],
         $args['option_name'],
         $args['name'],
         $args['label_for'],
         $args['description']);
   }

   /**
    * Accepts a two-dimensional array where each inner array consists of valid arguments for renderTextField.
    * @param array $args
    */
   public static function renderMultiTextField($args) {
      foreach ($args as $arg) {
         self::renderTextField($arg);
      }
   }

   /**
    * Render a select field.
    * @param array $args
    */
   public static function renderSelectField($args) {
      printf('<select name="%1$s[%2$s]" id="%3$s">',
          $args['option_name'],
          $args['name'],
          $args['label_for']);

      foreach ($args['options'] as $val) {
         printf('<option value="%1$s" %2$s>%3$s</option>',
             $val,
             selected($val, $args['value'], false),
             $val,
             $args['description']);
      }

      print '</select> ' . $args['description'];
   }

   /**
    * Wraps the PHP exit language construct.
    */
   public static function _exit() {
      exit;
   }

   /**
    * Blocks instantiation. All functions are static.
    */
   private function __construct() {

   }
}
```