UIActivities in Swift 3

Question

Trying to re-integrate the sharing button in my application. Apple again changed things in Swift 3 for iOS 10. I just updated to the Xcode 8 release version and it's been giving me some issues with UIActivities.

Found that many of them now begin with UIActivityType. in order for the compiler to not fail. However many of them still are using com.apple it also made me cast the activityType array to type [Any] for some reason.

So with that... Does anyone know why they did that? and what do you put in the for argument in the activityTypesToExclude.contains(where: (Any) throws -> Bool) method?

 internal func _shouldExcludeActivityType(_ activity: UIActivity) -> Bool {

            let activityTypesToExclude = [

                "com.apple.reminders.RemindersEditorExtension",
                UIActivityType.openInIBooks,
                UIActivityType.print,
                UIActivityType.assignToContact,
                UIActivityType.postToWeibo,
                "com.google.Drive.ShareExtension",
                "com.apple.mobileslideshow.StreamShareService"

            ] as [Any]

            if let actType = activity.activityType {
                if activityTypesToExclude.contains(where: (Any) throws -> Bool) {
                    return true
                }
                else if super.excludedActivityTypes != nil {
                    return super.excludedActivityTypes!.contains(actType)
                }
            }
            return false
}

score 7 · Accepted Answer · answered Sep 20 '16 at 18:54

UIActivityType is a type-safe thin wrapper for String representation of activity type. If you have found some activity types which has no predefined constants, you can define your own with extension.

extension UIActivityType {
    static let remindersEditorExtension = UIActivityType(rawValue: "com.apple.reminders.RemindersEditorExtension")
    static let googleDriveShareExtension = UIActivityType(rawValue: "com.google.Drive.ShareExtension")
    static let streamShareService = UIActivityType(rawValue: "com.apple.mobileslideshow.StreamShareService")
}

With the extension above, you can write something like this:

internal func _shouldExcludeActivityType(_ activity: UIActivity) -> Bool {

    let activityTypesToExclude: [UIActivityType] = [
        .remindersEditorExtension,
        .openInIBooks,
        .print,
        .assignToContact,
        .postToWeibo,
        .googleDriveShareExtension,
        .streamShareService
    ]

    if let actType = activity.activityType {
        if activityTypesToExclude.contains(actType) {
            return true
        } else if let superExcludes = super.excludedActivityTypes {
            return superExcludes.contains(actType)
        }
    }
    return false
}

You should not use raw String representations directly in Swift 3 code.

So, about why they did that?: with this change, programmers get far less chance to accidentally include non-activityType Strings where activityType identifiers needed.

Similar changes have been made for some String constants, for example Notification.Name.

I'm kind of confused on how to use this function. I've tried ```activityViewController.excludedActivityTypes = [UIActivityType.streamShareService]``` and it doesnt work. Can you please explain how to use the function ```_shouldExcludeActivityType``` so that I can exclude ```com.apple.mobileslideshow.StreamShareService``` — breaktop, Dec 26 '16 at 21:58
First of all, check [this thread](http://stackoverflow.com/q/31792506/6541007). (Maybe you have already checked it, but again carefully.) As written in the accepted answer, `_shouldExcludeActivityType` is a private API and apps using this API are in risk rejected by Apple. And Apple, at any time, would change some detailed implementations without notifications. You can try them with your own risk, but I cannot explain "how to use it" because I do not know what actually will work. The answer above is just explaining how to create an instance of `UIActivityType`. — OOPer, Dec 27 '16 at 03:32

UIActivities in Swift 3

1 Answers1