# document-gallery/3.5.4/admin/class-admin.php

Document Gallery, version 3.5.4. 1,376 lines.

- Page: https://pluginprobe.com/plugins/document-gallery/3.5.4/code/admin/class-admin.php
- Raw: https://pluginprobe.com/plugins/document-gallery/3.5.4/raw/admin/class-admin.php
- Modified: 2015-11-14T04:06:48+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/3.5.4/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 array Associative array containing all tab names, keyed by tab slug.
	 */
	private static $tabs;

	/**
	 * @var array The URL parameters. Currently only used in the thumbnail mgmt tab.
	 */
	private static $URL_params;

	/**
	 * 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'] . '">' .
			           '<span class="dashicons dashicons-heart"></span> ' .
			           __( '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 ( in_array( $hook, array( DG_Admin::$hook, 'post.php', 'post-new.php' ), true ) ) {
			// Settings Page
			DG_Util::enqueueAsset( 'document-gallery-admin', 'assets/css/admin.css' );

			// gracefully degrade for older WP versions
			if ( version_compare( get_bloginfo( 'version' ), '3.8', '<' ) ) { ?>
				<style type="text/css">
					.dashicons, .nav-tab:before, .deleteSelected:before, .clearLog:before, .expandAll:before,
					.collapseAll:before, .logLabel.date:before, .collapser:after, .expander:after,
					#ThumbsTable .title a:after, #LogTable>tbody a:after {
						display: none !important;
					}
				</style>
			<?php }

			DG_Util::enqueueAsset( 'document-gallery-admin', 'assets/js/admin.js', array( 'jquery' ) );
			wp_localize_script( 'document-gallery-admin', 'dg_admin_vars', array( 'upload_limit' => wp_max_upload_size() ) );
			if ( $hook !== self::$hook ) { //if $hook is 'post.php' or 'post-new.php'
				wp_localize_script( 'document-gallery-admin', 'ajax_object', array( 'ajax_url' => admin_url( 'admin-ajax.php' ) ) );

				// Media Manager
				global $dg_options;
				DG_Util::enqueueAsset( 'document-gallery-media-manager', 'assets/js/media_manager.js', array( 'media-views' ) );
				wp_localize_script( 'document-gallery-media-manager', 'DGl10n', array(
					'documentGalleryMenuTitle'   => __( 'Create Document Gallery', 'document-gallery' ),
					'documentGalleryButton'      => __( 'Create a new Document Gallery', 'document-gallery' ),
					'cancelDocumentGalleryTitle' => '&#8592; ' . __( 'Cancel Document Gallery', 'document-gallery' ),
					'updateDocumentGallery'      => __( 'Update Document Gallery', 'document-gallery' ),
					'insertDocumentGallery'      => __( 'Insert Document Gallery', 'document-gallery' ),
					'addToDocumentGallery'       => __( 'Add to Document Gallery', 'document-gallery' ),
					'addToDocumentGalleryTitle'  => __( 'Add to Document Gallery', 'document-gallery' ),
					'editDocumentGalleryTitle'   => __( 'Edit Document Gallery', 'document-gallery' )
				) );
				wp_localize_script( 'document-gallery-media-manager', 'documentGalleryDefaults', $dg_options['gallery'] );
			}
		}
	}

	/**
	 * Load Document Gallery Custom templates.
	 */
	public static function loadCustomTemplates() {
		include_once DG_PATH . 'admin/media-manager-template.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_new_window', 'new_window',
			array( __CLASS__, 'renderCheckboxField' ),
			DG_OPTION_NAME, 'gallery_defaults',
			array(
				'label_for'   => 'label_gallery_defaults_new_window',
				'name'        => 'gallery_defaults][new_window',
				'value'       => esc_attr( $defaults['new_window'] ),
				'option_name' => DG_OPTION_NAME,
				'description' => __( 'Open thumbnail links in new window', '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', 'document-gallery' ),
			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', 'document-gallery' ),
			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_enabled', __( 'Logging Enabled', 'document-gallery' ),
			array( __CLASS__, 'renderCheckboxField' ),
			DG_OPTION_NAME, 'advanced',
			array(
				'label_for'   => 'label_advanced_logging_enabled',
				'name'        => 'logging_enabled',
				'value'       => esc_attr( $dg_options['logging']['enabled'] ),
				'option_name' => DG_OPTION_NAME,
				'description' => __( 'Whether to log debug and error information related to Document Gallery.', 'document-gallery' )
			) );

		add_settings_field(
			'advanced_logging_purge_interval', __( 'Logging Purge Interval', 'document-gallery' ),
			array( __CLASS__, 'renderTextField' ),
			DG_OPTION_NAME, 'advanced',
			array(
				'label_for'   => 'label_advanced_logging_purge_interval',
				'name'        => 'logging_purge_interval',
				'value'       => esc_attr( $dg_options['logging']['purge_interval'] ),
				'type'        => 'number" min="0" step="1',
				'option_name' => DG_OPTION_NAME,
				'description' => __( 'Number of days to keep old log entries (0 disables purging).', 'document-gallery' )
			) );

		add_settings_field(
			'advanced_gs', __( 'Ghostscript Absolute Path', 'document-gallery' ),
			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 ) {
		// NOTE: WP double-calls this function -- below logic prevents potential
		//       side effects by processing a maximum of one call to validate
		//       per page load, re-returning the previous result on any
		//       subsequent calls.
		static $ret = null;
		if ( is_null( $ret ) ) {
			if ( empty( $values['tab'] ) || ! array_key_exists( $values['tab'], self::getTabs() ) ) {
				global $dg_options;
				return $dg_options;
			} else {
				if ( array_key_exists( 'ajax', $values ) ) {
					unset( $values['ajax'] );
					define( 'DOING_AJAX', true );
				}

				$funct = 'validate' . $values['tab'] . 'Settings';
				unset( $values['tab'] );
				$ret = DG_Admin::$funct( $values );
			}
		}

		return $ret;
	}

	/**
	 * 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 $k2 => $v2 ) {
						if ( empty( $v['thumber'] ) ) {
							unset( $ret['thumber']['thumbs'][ $k2 ] );
						}
					}
					break;
				}
			}
		}

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

		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          = DG_Util::hasThumb( $ID ) ? $ret['thumber']['thumbs'][ $ID ]['thumb_path'] : null;
			$uploaded_filename = self::validateUploadedFile();
			if ( $uploaded_filename && DG_Thumber::setThumbnail( $ID, $uploaded_filename ) ) {
				if ( ! is_null( $old_path ) && $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 ( defined( 'DOING_AJAX' ) && DOING_AJAX ) {
			@header( 'Content-Type: application/json; charset=' . get_option( 'blog_charset' ) );
			echo wp_json_encode( $responseArr );
			add_filter( 'wp_redirect', array( __CLASS__, '_exit' ), 1, 0 );
		}

		return $ret;
	}

	/**
	 * Validates uploaded file as a semi for potential thumbnail.
	 *
	 * @param  string $var File field name.
	 *
	 * @return bool|string   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'] );
			}
		}

		// logging settings
		$ret['logging']['enabled'] = isset( $values['logging_enabled'] );
		if ( isset( $values['logging_purge_interval'] ) ) {
			$purge_interval = (int) $values['logging_purge_interval'];
			if ( $purge_interval >= 0 ) {
				$ret['logging']['purge_interval'] = $purge_interval;
			} else {
				add_settings_error( DG_OPTION_NAME, 'thumber-logging-purge-interval',
					__( 'Invalid logging purge interval given: ', 'document-gallery' ) . $values['logging_purge_interval'] );
			}
		}

		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>.', 'document-gallery' ),
				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';
		static $limit_options = array( 10, 25, 75 );
		static $order_options = array( 'asc', 'desc' );
		static $orderby_options = array( 'date', 'title' );
		$options = DG_Thumber::getOptions();

		// find subset of thumbs to be included
		self::$URL_params = array( 'page' => DG_OPTION_NAME, 'tab' => 'Thumbnail' );
		$orderby = self::$URL_params['orderby'] = self::getOrderbyParam($orderby_options);
		$order = self::$URL_params['order'] = self::getOrderParam($order_options);
		$limit = self::$URL_params['limit'] = self::getLimitParam($limit_options);

		$thumbs        = $options['thumbs'];
		uasort( $thumbs, array( __CLASS__, 'cmpThumb' ) );
		$thumbs_number = count( $options['thumbs'] );
		$lastsheet     = ceil( $thumbs_number / $limit );
		$sheet         = array_key_exists( 'sheet', $_REQUEST ) ? absint( $_REQUEST['sheet'] ) : 1;
		if ( $sheet === 0 || $sheet > $lastsheet ) {
			$sheet = 1;
		}

		$offset = ( $sheet - 1 ) * $limit;
		$thumbs = array_slice( $thumbs, $offset, $limit, true );

		// https://core.trac.wordpress.org/ticket/12212
		$posts = array();
		if ( ! empty( $thumbs ) ) {
			$posts = get_posts(
				array(
					'post_type'   => 'any',
					'post_status' => 'any',
					'numberposts' => - 1,
					'post__in'    => array_keys( $thumbs ),
					'orderby'     => 'post__in'
				) );
		}

		foreach ( $posts as $post ) {
			$path_parts         = pathinfo( $post->guid );

			$t                  = &$thumbs[$post->ID];
			$t['title']         = !empty( $post->post_title ) ? $post->post_title : $path_parts['filename'];
			$t['ext']           = array_key_exists( 'extension', $path_parts ) ? $path_parts['extension'] : '';
			$t['description']   = $post->post_content;
			$t['icon']          = array_key_exists( 'thumb_url', $t )
										? $t['thumb_url']
										: DG_Thumber::getDefaultThumbnail( $post->ID );
		}
		unset( $posts );

		$select_limit        = '';
		foreach ( $limit_options as $l_o ) {
			$select_limit .= '<option value="' . $l_o . '"' . selected( $limit, $l_o, false ) . '>' . $l_o . '</option>' . PHP_EOL;
		}

		$thead = '<tr>' .
		         '<th scope="col" class="manage-column column-cb check-column">' .
		         '<label class="screen-reader-text" for="cb-select-all-%1$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 ' . $order ) . '"><a href="?' . http_build_query( array_merge( self::$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 ' . $order ) . '"><a href="?' . http_build_query( array_merge( self::$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' ) . '"' . ( $sheet == 1 ? '' : ' href="?' . http_build_query( self::$URL_params ) . '"' ) . '>«</a>' .
				'<a class="prev-page' . ( $sheet == 1 ? ' disabled' : '' ) . '" title="' . __( 'Go to the previous page', 'document-gallery' ) . '"' . ( $sheet == 1 ? '' : ' href="?' . http_build_query( array_merge( self::$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 == $lastsheet ? '' : ' href="?' . http_build_query( array_merge( self::$URL_params, array( 'sheet' => $sheet + 1 ) ) ) . '"' ) . '>›</a>' .
				'<a class="last-page' . ( $sheet == $lastsheet ? ' disabled' : '' ) . '" title="' . __( 'Go to the last page', 'document-gallery' ) . '"' . ( $sheet == $lastsheet ? '' : ' href="?' . http_build_query( array_merge( self::$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 wp_json_encode( self::$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
					foreach ( $thumbs as $tid => $thumb ) {
						$icon        = $thumb['icon'];
						$title       = $thumb['title'];
						$ext         = $thumb['ext'];
						$description = $thumb['description'];
						$date        = DocumentGallery::localDateTimeFromTimestamp( $thumb['timestamp'] );
						?>
						<tr data-entry="<?php echo $tid; ?>">
							<td scope="row" class="check-column">
								<input
									type="checkbox"
									class="cb-ids"
									name="<?php echo DG_OPTION_NAME; ?>[ids][]"
									value="<?php echo $tid; ?>">
							</td>
							<td class="column-icon media-icon"><img src="<?php echo $icon; ?>" /></td>
							<td class="title column-title">
								<strong>
									<a
										href="<?php echo home_url( '/?attachment_id=' . $tid ); ?>"
										target="_blank"
										title="<?php sprintf( __( "View '%s' attachment page", 'document-gallery' ), $title ); ?>">
										<span class="editable-title"><?php echo $title; ?></span>
										<sup><?php echo $ext; ?></sup>
									</a>
								</strong>
								<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"><?php echo $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 class="dashicons dashicons-update"></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<?php echo $tid; ?>" type="file" />
										<input id="trigger-button<?php echo $tid; ?>" type="button" value="Select File" class="button" />
									</span>
								</span>
								<div class="progress animate invis">
									<span><span></span></span>
								</div>
							</td>
							<td class="date column-date"><?php echo $date; ?></td>
						</tr>
						<?php
					} ?>
					</tbody>
				</table>
				<div class="tablenav bottom"><?php echo $pagination; ?></div>
			</div>
		</div>
	<?php }

	/**
	 * @param $limit_options array The possible options for limit. If no limit was provided then this is used to find a default limit.
	 *
	 * @return int The limit, which may or may not be a member of $limit_options.
	 */
	private static function getLimitParam($limit_options) {
		return array_key_exists( 'limit', $_REQUEST ) ? DG_Util::posint( $_REQUEST['limit'] ) : $limit_options[0];
	}

	/**
	 * @param $order_options array The possible options for order.
	 *
	 * @return string The order value.
	 */
	private static function getOrderParam($order_options) {
		$ret = array_key_exists( 'order', $_REQUEST ) ? strtolower( $_REQUEST['order'] ) : '';
		return in_array($ret, $order_options) ? $ret : $order_options[0];
	}

	/**
	 * @param $orderby_options array The possible options for orderby.
	 *
	 * @return string The orderby value.
	 */
	private static function getOrderbyParam($orderby_options) {
		$ret = array_key_exists( 'orderby', $_REQUEST ) ? strtolower( $_REQUEST['orderby'] ) : '';
		return in_array($ret, $orderby_options) ? $ret : $orderby_options[0];
	}

	/**
	 * 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'
			);
		}
		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 ] ) ) {
			$old_path          = DG_Util::hasThumb($ID) ? $dg_options['thumber']['thumbs'][ $ID ]['thumb_path'] : null;
			$uploaded_filename = self::validateUploadedFile();
			if ( $uploaded_filename && DG_Thumber::setThumbnail( $ID, $uploaded_filename ) ) {
				if ( ! is_null($old_path) && $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'] ) ) {
			wp_send_json( $responseArr );
		}
	}

	/**
	 * 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() ) );

			$fmt =
				'<tr>' .
				'<th scope="col" class="manage-column column-date sorted desc"><a href="javascript:void(0);">' .
				'<span>%s</span><span class="sorting-indicator"></span></a>' .
				'</th>' .
				'<th scope="col" class="manage-column column-level"><span>%s</span></th>' .
				'<th scope="col" class="manage-column column-message"><span>%s</span></th>' .
				'</tr>';

			$thead = sprintf( $fmt,
				__( 'Date', 'document-gallery' ),
				__( 'Level', 'document-gallery' ),
				__( 'Message', 'document-gallery' ) );

			?>
			<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
						for ( $i = count( $log_list ); $i > 0; $i -- ) {
							$log_entry = $log_list[ $i - 1 ];
							$date      = DocumentGallery::localDateTimeFromTimestamp( $log_entry[0] );

							// convert attachment names to links
							$log_entry[2] = preg_replace( '/[ ^](attachment #)(\d+)[.,: ]/i', ' <a href="' . home_url() . '/?attachment_id=\2" target="_blank">\1<strong>\2</strong></a> ', $log_entry[2] );

							// bold the place where log entry was submitted
							$log_entry[2] = preg_replace( '/^(\((?:\w+(?:::|->))?\w+\)) /', '<strong>\1</strong> ', $log_entry[2] );

							// italicize any function references within log entry
							$log_entry[2] = preg_replace( '/(\(?\w+(?:::|->)\w+\)?)/m', '<i>\1</i>', $log_entry[2] );

							echo '<tr><td class="date column-date" data-sort-value="' . $log_entry[0] . '"><span class="logLabel date">' . $date . '</span></td>' .
							     '<td class="column-level">' . $levels[ $log_entry[1] ] . '</td>' .
							     '<td class="column-entry">' . ( empty( $log_entry[3] ) ? '<pre>' . $log_entry[2] . '</pre>' : '<div class="expander" title="Click to Expand"><pre>' . $log_entry[2] . '</pre><div><span class="dashicons dashicons-arrow-down-alt2"></span></div></div><div class="spoiler-body"><pre>' . $log_entry[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'];
	}

	/**
	 * @param $t1 array Thumbnail array #1.
	 * @param $t2 array Thumbnail array #2
	 *
	 * @return int The result of comparing the two thumbnail arrays using arguments in $URL_params.
	 */
	public static function cmpThumb($t1, $t2) {
		$ret = 0;
		switch (self::$URL_params['orderby']) {
			case 'date':
				$ret = $t1['timestamp'] - $t2['timestamp'];
				break;

			case 'title':
				$ret = strcmp( basename( $t1['thumb_path'] ), basename( $t2['thumb_path'] ) );
				break;
		}

		return 'asc' === self::$URL_params['order'] ? $ret : -$ret;
	}

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

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

	}
}
```