nserror

I have some Objective-C legacy code, that declares method like - (void)doSomethingWithArgument:(ArgType)argument error:(NSError **)error As written here https://developer.apple.com/library/ios/documentation/Swift/Conceptual/BuildingCocoaApps/AdoptingCocoaDesignPatterns.html Swift automatically translates Objective-C methods that produce errors into methods that throw an error according to Swift’s native error handling functionality. But in my project described methods are called like this: object.doSomething(argument: ArgType, error: NSErrorPointer) Moreover, it throws runtime exception when I

Let's say that you have a function like this: func getSomething(error: NSErrorPointer) -> Something and you typically use it this way: var error : NSError? = nil let a = getSomething(&error) What is an idiomatic way to check for error here? More specific questions: If error == nil can we assume that a will never be nil and vice versa? What should we check first: error (for its nilness) or a (to confirm that it's not a nil)? Can a != nil && error != nil be true in some cases? Thank you! Compare Handling Error Objects Returned From Methods in the "Error Handling Programming Guide": Important:

I am working on catching errors in my app, and I am looking into using NSError . I am slightly confused about how to use it, and how to populate it. Could someone provide an example on how I populate then use NSError ? Alex Well, what I usually do is have my methods that could error-out at runtime take a reference to a NSError pointer. If something does indeed go wrong in that method, I can populate the NSError reference with error data and return nil from the method. Example: - (id) endWorldHunger:(id)largeAmountsOfMonies error:(NSError**)error { // begin feeding the world's children... // it

I am working on an iOS project. In this application, I am downloading images from the server. Problem: While downloading images I am getting Request Timeout . According to documentation HTTP status code of request timeout is 408 . But in my application, I am getting HTTP status code 0 with the following error Error Domain=NSURLErrorDomain Code=-1001 "The request timed out." UserInfo=0xb9af710 {NSErrorFailingURLStringKey= http://xxxx.com/resources/p/PNG/1383906967_5621_63.jpg , NSErrorFailingURLKey= http://xxxx.com/resources/p/PNG/1383906967_5621_63.jpg , NSLocalizedDescription=The request

I have just completed an iPhone app programming course. As part of the course, I saw Objective-C provides exception handling using the @try directive The system library does not use exception handling, preferring to return nil I asked if I should use exception handling for new code I wrote (e.g. if I write both the front-end and logic code, so the communication between them is in my hands) but I was told no, one should not use exceptions for new code. (But he failed to elaborate, then the class moved on, I thought perhaps the reason would become clear later..) Surely exceptions are superior to