<?php
if ( ! class_exists( 'wsScreenOptions12' ) ) :
/**
* Class for adding new panels to the "Screen Options" box.
*
* Do not access this class directly. Instead, use the add_screen_options_panel() function.
*
* @author Janis Elsts
* @copyright 2014
* @version 1.3
* @access public
*/
class wsScreenOptions13 {
var $registered_panels; //List of custom "Screen Options" panels
var $page_panels; //Index of panels registered for each page ($page => array of panel ids).
/**
* Class constructor
*
* @return void
*/
function init() {
$this->registered_panels = array();
$this->page_panels = array();
add_action( 'current_screen', array( $this, 'populate_page_panels' ) );
add_filter( 'screen_settings', array( &$this, 'append_screen_settings' ), 10, 2 );
add_action( 'admin_print_scripts', array( &$this, 'add_autosave_script' ) );
}
/**
* Add a new settings panel to the "Screen Options" box.
*
* @param string $id String to use in the 'id' attribute of the settings panel. Should be unique.
* @param string $title Title of the settings panel. Set to an empty string to omit title.
* @param callback $callback Function that fills the panel with the desired content. Should return its output.
* @param string|array $page The page(s) on which to show the panel (similar to add_meta_box()).
* @param callback $save_callback Optional. Function that saves the settings.
* @param bool $autosave Optional. If set, settings will be automatically saved (via AJAX) when the value of any input element in the panel changes. Defaults to false.
* @return void
*/
function add_screen_options_panel( $id, $title, $callback, $page, $save_callback = null, $autosave = false ) {
if ( ! is_array( $page ) ) {
$page = array( $page );
}
$new_panel = array(
'title' => $title,
'callback' => $callback,
'page' => $page,
'save_callback' => $save_callback,
'autosave' => $autosave,
);
$this->registered_panels[ $id ] = $new_panel;
if ( $save_callback ) {
add_action( 'wp_ajax_save_settings-' . $id, array( $this, 'ajax_save_callback' ) );
}
}
/**
* Populate a lookup array for screen -> panels queries.
*
* This is a callback for the "current_screen" action. We have to do it in this hook or WordPress will
* complain about "doing it wrong" and incorrectly suggest using the "add_meta_boxes" action.
*
* "add_meta_boxes" doesn't work here because it only gets called on CPT pages and we want the ability
* to add screen options to any page.
*/
function populate_page_panels() {
foreach ( $this->registered_panels as $id => $panel ) {
$page = $panel['page'];
//Convert page hooks/slugs to screen IDs
$page = array_map( array( $this, 'page_to_screen_id' ), $page );
$page = array_unique( $page );
//Store the panel ID in each relevant page's list
foreach ( $page as $page_id ) {
if ( ! isset( $this->page_panels[ $page_id ] ) ) {
$this->page_panels[ $page_id ] = array();
}
$this->page_panels[ $page_id ][] = $id;
}
}
}
/**
* Convert a page hook name to a screen ID.
*
* @uses convert_to_screen()
* @access private
*
* @param string $page
* @return string
*/
function page_to_screen_id( $page ) {
if ( function_exists( 'convert_to_screen' ) ) {
$screen = convert_to_screen( $page );
if ( isset( $screen->id ) ) {
return $screen->id;
} else {
return '';
}
} else {
return str_replace( array( '.php', '-new', '-add' ), '', $page );
}
}
/**
* Append custom panel HTML to the "Screen Options" box of the current page.
* Callback for the 'screen_settings' filter (available in WP 3.0 and up).
*
* @access private
*
* @param string $current
* @param string $screen Screen object (undocumented).
* @return string The HTML code to append to "Screen Options"
*/
function append_screen_settings( $current, $screen ) {
global $hook_suffix;
//Sanity check
if ( ! isset( $screen->id ) ) {
return $current;
}
//Are there any panels that want to appear on this page?
$panels = $this->get_panels_for_screen( $screen->id, $hook_suffix );
if ( empty( $panels ) ) {
return $current;
}
//Append all panels registered for this screen
foreach ( $panels as $panel_id ) {
$panel = $this->registered_panels[ $panel_id ];
//Add panel title
if ( ! empty( $panel['title'] ) ) {
$current .= "\n<h5>" . $panel['title'] . "</h5>\n";
}
//Generate panel contents
if ( is_callable( $panel['callback'] ) ) {
$contents = call_user_func( $panel['callback'] );
$classes = array(
'custom-options-panel',
);
if ( $panel['autosave'] ) {
$classes[] = 'requires-autosave';
}
$contents = sprintf(
'<div id="%s" class="%s"><input type="hidden" name="_wpnonce-%s" value="%s" />%s</div>',
esc_attr( $panel_id ),
implode( ' ', $classes ),
esc_attr( $panel_id ),
wp_create_nonce( 'save_settings-' . $panel_id ),
$contents
);
$current .= $contents;
}
}
return $current;
}
/**
* AJAX callback for the "Screen Options" autosave.
*
* @access private
* @return void
*/
function ajax_save_callback() {
if ( empty( $_POST['action'] ) ) {
die( '0' );
}
//The 'action' argument is in the form "save_settings-panel_id"
$id = end( explode( '-', $_POST['action'], 2 ) );
//Basic security check.
check_ajax_referer( 'save_settings-' . $id, '_wpnonce-' . $id );
//Hand the request to the registered callback, if any
if ( ! isset( $this->registered_panels[ $id ] ) ) {
exit( '0' );
}
$panel = $this->registered_panels[ $id ];
if ( is_callable( $panel['save_callback'] ) ) {
call_user_func( $panel['save_callback'], $_POST );
die( '1' );
} else {
die( '0' );
}
}
/**
* Add/enqueue supporting JavaScript for the autosave function of custom "Screen Options" panels.
*
* Checks if the current page is supposed to contain any autosave-enabled
* panels and adds the script only if that's the case.
*
* @return void
*/
function add_autosave_script() {
//Get the page id/hook/slug/whatever.
global $hook_suffix;
//Check if we have some panels with autosave registered for this page.
$panels = $this->get_panels_for_screen( '', $hook_suffix );
if ( empty( $panels ) ) {
return;
}
$got_autosave = false;
foreach ( $panels as $panel_id ) {
if ( $this->registered_panels[ $panel_id ]['autosave'] ) {
$got_autosave = true;
break;
}
}
if ( $got_autosave ) {
//Enqueue the script itself
$url = plugins_url( 'screen-options.js', __FILE__ );
wp_enqueue_script( 'screen-options-custom-autosave', $url, array( 'jquery' ) );
}
}
/**
* Get custom panels registered for a particular screen and/or page.
*
* @param string $screen_id Screen ID.
* @param string $page Optional. Page filename or hook name.
* @return array Array of custom panels.
*/
function get_panels_for_screen( $screen_id, $page = '' ) {
if ( isset( $this->page_panels[ $screen_id ] ) && ! empty( $this->page_panels[ $screen_id ] ) ) {
$panels = $this->page_panels[ $screen_id ];
} else {
$panels = array();
}
if ( ! empty( $page ) ) {
$page_as_screen = $this->page_to_screen_id( $page );
if ( isset( $this->page_panels[ $page_as_screen ] ) && ! empty( $this->page_panels[ $page_as_screen ] ) ) {
$panels = array_merge( $panels, $this->page_panels[ $page_as_screen ] );
}
}
return array_unique( $panels );
}
}
//All versions of the class are stored in a global array
//and only the latest version is actually used.
global $ws_screen_options_versions;
if ( ! isset( $ws_screen_options_versions ) ) {
$ws_screen_options_versions = array();
}
$ws_screen_options_versions['1.3'] = 'wsScreenOptions13';
endif;
if ( ! function_exists( 'add_screen_options_panel' ) ) {
/**
* Add a new settings panel to the "Screen Options" box.
*
* @see wsScreenOptions10::add_screen_options_panel()
*
* @param string $id String to use in the 'id' attribute of the settings panel. Should be unique.
* @param string $title Title of the settings panel. Set to an empty string to omit title.
* @param callback $callback Function that fills the panel with the desired content. Should return its output.
* @param string|array $page The page(s) on which to show the panel (similar to add_meta_box()).
* @param callback $save_callback Optional. Function that saves the settings contained in the panel.
* @param bool $autosave Optional. If set, settings will be automatically saved (via AJAX) when the value of any input element in the panel changes. Defaults to false.
* @return void
*/
function add_screen_options_panel( $id, $title, $callback, $page, $save_callback = null, $autosave = false ) {
global $ws_screen_options_versions;
static $instance = null; /** @var wsScreenOptions13 $instance */
if ( is_null( $instance ) ) {
//Instantiate the latest version of the wsScreenOptions class
uksort( $ws_screen_options_versions, 'version_compare' );
$className = end( $ws_screen_options_versions );
$instance = new $className;
$instance->init();
}
$instance->add_screen_options_panel( $id, $title, $callback, $page, $save_callback, $autosave );
}
}