Breaking: #79196 - Toolbar item event handling changed

Description

With the introduction of the topbar reloading mechanism, the event handling of toolbar items has changed. Reason is that the event information gets lost, as the whole topbar is rendered from scratch after a reload.

Impact

After reloading the topbar, non-migrated events will not get triggered anymore.

Affected Installations

All installations with old-fashioned toolbar item registrations.

Migration

In most cases it's sufficient to replace the register function with Viewport.Topbar.Toolbar.registerEvent().

Example:

define(['jquery', 'TYPO3/CMS/Backend/Viewport'], function($, Viewport) {
   // old registration
   MyAwesomeItem.doStuff)

   // new registration
   Viewport.Topbar.Toolbar.registerEvent(MyAwesomeItem.doStuff);
});