A protocol that delegates of a URL connection implement to receive status about and provide feedback to the connection object.
- iOS 5.0+
- macOS 10.7+
- tvOS 9.0+
- watchOS 2.0+
NSURLConnection objects should implement either the
NSURLConnection protocol in addition to the
NSURLConnection protocol. Specifically:
Otherwise, the delegate class should implement the
Delegates that wish to perform custom authentication handling should implement the
connection(_: method, which is the preferred mechanism for responding to authentication challenges. (See
URLAuthentication for more information on authentication challenges.) If
connection(_: is not implemented, the older, deprecated methods
connection(_: are called instead.
connection(_: method is called at most once if an error occurs during the loading of a resource. The
connection method is called once, just before the loading of a resource begins.