system.updater.beforeUpdate

Triggered in System\Widgets\Updater.

Called before the software update process begins from the backend.

A non-null return value stops the update and is used as the AJAX response. Throwing an exception will halt the update with an error.

Example usage:

Event::listen('system.updater.beforeUpdate', function () {
    Flash::success('Update started');
    return Redirect::refresh();
});