A proxy for data passed to an activity view controller.
- iOS 6.0+
You can use a provider object in situations where you want to make data available for use by an activity but you want to delay providing that data until it is actually needed. For example, you might use a provider object to represent a large video file that needs to be processed before it can be shared to a user’s social media account.
When you initialize a
UIActivity object, you can pass a provider object in addition to any other data objects. When the user selects an activity, the activity view controller adds your provider object (which is also an operation object) to an operation queue so that it can begin to gather or process the needed data.
You must subclass
UIActivity and implement its
item method, which is called to generate the item data. You implement this method instead of the normal
main() method you would implement for an operation object. (The
main() method calls the
item method when the operation object is executed.) Your implementation of the
item method should do whatever work is necessary to create and return the data.