Breaking: #63431 - Backend toolbar refactored

See forge#63431

Description

The upper right backend toolbar has been refactored with TYPO3 CMS 7.0. A new PHP interface and a new registration were introduced.

Impact

Extensions that are not adapted to the new interface will not show up in the toolbar anymore, but will not throw a fatal PHP error.

Method BackendController::addToolbarItem() has been marked as deprecated.

Affected installations

If a TYPO3 CMS instance uses extensions based on the old interface and registration, the according items will no longer show up in the toolbar.

Migration

Extensions must implement the new interface TYPO3CMSBackendToolbarToolbarItemInterface and must be registered in $GLOBALS['TYPO3_CONF_VARS']['BE']['toolbarItems'].

Warning: The new interface is not 100% finished, method checkAccess() will probably be substituted by two other methods in later versions of TYPO3 CMS.