Note:

If an update is targeted to multiple items during one operation call, the observer is informed only once about the completion. This is done, when the update operation as a whole has been completed.

When the application updates itself, installation requires the shutdown of the application. Then, the updater will continue the update operation in the background but callbacks to nonexisting observers are skipped. After installation is finished, the updated application will be restarted if that information is included in CIAUpdateParameters.

An application may also update itself without a need for restart. For example, when plug-ins are retrieved for the application. Then, the callback functions of the observer can be called from the updater. And, the observer will know when the necessary updates have been installed.