NSString *className; //assume this exists Class class = NSClassFromString(className); if ([class conformsToProtocol:@protocol(SomeProtocol)]) { id instance = [[class alloc] init]; [instance create]; }
One of the following should do it: Close the connection (reset or normal close) Write a malformed chunk (and close the connection) which will trigger client error Add a http trailer telling your client that something went wrong. Change your higher level protocol. Last piece of data you send is a hash or a length … Read more
Update. In the latest Swift version you can just write protocol TransmogrifiableView: NSView { func transmogrify() } , and this will enforce the conformer types to be either NSView, or a subclass of it. This means the compiler will “see” all members of NSView. Original answer There is a workaround by using associated types to … Read more
Use a generic type constrained to Encodable func saveObject<T : Encodable>(_ object: T, at location: String) { //Some code let data = try JSONEncoder().encode(object) //Some more code }
I’ve not had occasion to use it, but some time ago I bookmarked OS X URL handler to open links to local files which is exactly what you’re looking for. The important part of the linked procedure is adding an appropriate CFBundleURLTypes to your application’s Info.plist that describes the scheme. The example given there looks … Read more
Short answer: No. Long answer: how would this work? Imagine you could add methods to existing protocols? How would this work? Imagine we wanted to add another method to NSCoding, say -(NSArray *) codingKeys; This method is a required method that returns an array of the keys used to encoding the object. The problem is … Read more
LWT messages are not really concerned about detecting whether a client has gone offline or not (that task is handled by keepAlive messages). LWT messages are about what happens after the client has gone offline. The analogy is that of a real last will: If a person dies, she can formulate a testament, in which … Read more
Hyper Text Transfer Protocol (HTTP) is a protocol used for transferring web pages (like the one you’re reading right now). A protocol is really nothing but a standard way of doing things. If you were to meet the President of the United States, or the king of a country, there would be specific procedures that … Read more
Use a delegate if you want to talk to only one object. For example, a tableView has a delegate – only one object should be responsible for dealing with it. Use notifications if you want to tell everyone that something has happened. For example in low memory situations a notification is sent telling your app … Read more
Apple states in the “Swift Programming Languages Documentation”: If the protocol only requires a property to be gettable, the requirement can be satisfied by any kind of property, and it is valid for the property to be also settable if this is useful for your own code. For this reason, the five following Playground code … Read more