Manually highlight Wordpress admin menu item - wordpress

Question

Under Pages menu in Wordpress Admin page, I got this layout:
Pages
Edit (url: edit-pages.php)
Add New (url: page-new.php)
Special Pages (url: edit-pages.php?special-pages=true)
as you can see, I've added a new submenu item called Special Pages which is pretty much a link to to Edit page with custom filter. Because Wordpress use file name to identify and highlight the submenu item, so whenever I click on Special Pages, the Edit submenu item is selected. Is there anyway to force Wordpress to select Special Pages menu item instead?
Cheers

Answer 1

better solution:
add_filter('parent_file', 'my_plugin_select_submenu');
function my_plugin_select_submenu($file) {
global $plugin_page;
if ('__my-current-submenu-slug__' == $plugin_page) {
$plugin_page = '__my-submenu-slug-to-select__';
}
return $file;
}

Answer 2

To further clarify Ken Vu's answer, edit the global variables $submenu_file and $parent_file. E.g., to highlight your page:
global $submenu_file;
$submenu_file = "edit-pages.php?special-pages=true";
If you need to change the top-level item highlighted, use $parent_file. E.g., highlight the "Writing" setting page:
global $parent_file;
global $submenu_file;
$parent_file = 'options-general.php';
$submenu_file = 'options-writing.php';

Answer 3

Solution: use $submenu_file variable
$submenu_file = "edit-pages.php?special-pages=true"

Answer 4

Thanks Ken Vu and Jonathan Brinley. Using your answers, I finally got the highlighting of my admin menu to work properly. As I struggled a bit to get it to work, I though I would post the entire result here, so other people can find it more easily :
The idea is to call the parent_file filter (undocumented, as many Wordpress parts unfornatunately). In my case, I was adding a custom menu instead of the default generated when creating a custom post type.
In my custom post code, I call the add_meta_boxes action. Within this hook, I issue my call to the parent_file filter :
add_filter('parent_file', array(&$this, 'highlight_admin_menu'));
_
Then this is how my hightlight_admin_menu function looks like :
function highlight_admin_menu($some_slug){
global $parent_file;
$parent_file = 'post.php?post=149&action=edit';
return $parent_file;
}
_
This got my menu to highlight properly. Try playing around with you own code to know where to issue the add_filter('parent_file', ...) code. Find a bit of code executed only on that particular page load, but soon enough that it is still possible to modify the $parent_file variable.
I hope this helps!

Answer 5

For changing the highlighted menu item for a submenu item, the proper filter is submenu_file.
add_filter('submenu_file', 'menuBold');
static function menuBold($submenu_file)
{
if ( checkProperPage($_GET) ) {
// The address of the link to be highlighted
return 'post-new?post_type=foobar&foo=bar';
}
// Don't change anything
return $submenu_file;
}
The check happens in WP's ~/wp-admin/menu-header.php file on line 194 (Wordpress 4.5.3):
if ( isset( $submenu_file ) ) {
if ( $submenu_file == $sub_item[2] )
$class[] = 'current';
...
}

Answer 6

You can modify this code to work for you. You can change both parent and submenu with that. Tested code.
function change_active_parent($submenu_file)
{
global $parent_file;
$zone = 'edit-tags.php?taxonomy=zone&post_type=product';
$storefront = 'edit-tags.php?taxonomy=storefront&post_type=product';
$container = 'edit-tags.php?taxonomy=container&post_type=product';
if (esc_html($zone) == $submenu_file) {
$parent_file = 'parent';
$submenu_file = $zone;
}
elseif (esc_html($storefront) == $submenu_file) {
$parent_file = 'parent';
$submenu_file = $storefront;
}
elseif (esc_html($container) == $submenu_file) {
$parent_file = 'parent';
$submenu_file = $container;
}
return $submenu_file;
}
add_filter( 'submenu_file', 'change_active_parent' );

Answer 7

Use the load-{$page_hook} action hook and modify the necessary globals:
/**
* For giggles, lets make an admin page that is not "in the menu" to play with.
*/
add_action('admin_menu', 'mort1305_admin_menu');
function mort1305_admin_menu() {
add_submenu_page(
NULL,
'Page Title',
'',
'administrator',
'my_slug',
'mort1305_page_content'
);
}
/**
* The menu item to highlight and the submenu item to embolden.
*/
add_action('load-admin_page_my_slug', 'mort1305_on_page_load');
function mort1305_on_page_load(){
global $plugin_file, $submenu_file, $title;
$plugin_page = 'slug-of-menu-item-to-be-highlighted';
$submenu_file = 'slug-of-submenu-item-to-be-bold';
foreach($submenu[NULL] as $submenu_arr) {
if($submenu_arr[2] === 'test_page_slug') {
$title = $submenu_arr[3];
break;
}
}
}
/**
* Page content to display.
*/
function mort_1305_page_content() {
echo This is the '. get_admin_page_title() .' page. The slug of my parent is '. get_admin_page_parent() .'.';
}