When an external app is launched using UIActivityViewController, can we detect which app was used in the completionHandler?
In Apple's documentation, there is mention of a property UIActivity.ActivityType, but it seems this is used only to detect "built-in activities". How can I detect if, eg. WhatsApp Messenger was launched?
When setting up your UIActivityViewController, use the completionWithItemsHandler to setup a completion closure that is called when the user makes a selection.
This completion block takes four parameters: the (optional) selected activity, a completion indicator, an optional array of returned items, and an error.
The selected activity is of type UIActivity.ActivityType. Its rawValue is a String representing the activity. If the activity type isn't one of the provided constants, compare its rawValue against a string you determine by running some tests to see its value for a given activity such as WhatsApp.