"Aliases" tab missing in network site settings

[villeveikkoilen]

Problem

One day I noticed that the Aliases settings tab was missing in network site settings. I traced the problem to The Events Calendar PRO plugin. When that plugin was activated, the tab disappeared, and when I deactivated it, the tab re-appeared.

In my understanding, the problem is in the following lines of code:

Mercator/admin.php

Lines 64 to 66 in 9240e7c

	if ( $GLOBALS['parent_file'] !== 'sites.php' || $GLOBALS['submenu_file'] !== 'sites.php' ) {
	return;
	}

For some reason, I don't know why, when TEC plugin is activated, $GLOBALS['submenu_file'] value is NULL, when it should be sites.php.

Versions

• WordPress: 5.9.3
• The Events Calendar PRO: 5.14.0.1
• Mercator: 1.0.3

Possible fix (POC)

There's a proper way of getting current admin screen instead of reading globals. My suggestion would be to replace these lines:

Mercator/admin.php

Lines 64 to 66 in 9240e7c

	if ( $GLOBALS['parent_file'] !== 'sites.php' || $GLOBALS['submenu_file'] !== 'sites.php' ) {
	return;
	}

with:

$current_screen = get_current_screen();

if ( empty($current_screen->id) || ($current_screen->id !== 'site-info-network' && $current_screen->id !== 'admin-network' ) ) {
	return;
}

[rumspeed]

Interesting find @villeveikkoilen. I have confirmed this behavior as I have a multisite using The Events Calendar and another one without it. The one that has TEC is missing the Aliases tab. I have discovered another issue as well.

Problem: When viewing a custom tab that has been added to a multisite using the network_edit_site_nav_links filter, the Alias tab also disappears.

From what I can see, Mercator is adding the Aliases tab using Javascript.

Mercator/admin.php

Lines 53 to 59 in 55e3f01

	/**
	* Output the site tab if we're on the right page
	*
	* Outputs the link, then moves it into place using JS, as there are no hooks to
	* speak of.
	*/
	function maybe_output_site_tab() {

At the time this might have been the only way to do it however there is a hook that can be used to avoid using JavaScript. Perhaps something like this to replace maybe_output_site_tab() ...

add_filter( 'network_edit_site_nav_links', 'mercator_add_settings_tab' );
 
function mercator_add_settings_tab( $tabs ) {

    // add a new tab to the Edit Site area for Sites
    $tabs['mercator-aliases-nav-link'] = array(
        'label' => 'Aliases',
        'url' => 'admin.php?action=mercator-aliases',
        'cap' => 'manage_sites'
    );

    return $tabs;
}