Using Restkit with Swift

Question

I am trying to use RestKit in my Swift based project. It seems like I can't use Swift primitive data types such as Int, Double, Bool, etc., Except for String, Array and Dictionaries (which seems to be due to the fact that they are duty-free connected to NSString. NSArray and NSDictionary)

With objective-c, I could define properties in my objects as primitive data types as properties that are assigned. In Swift, I can only use objects (String, NSNumber, Array, Dictionary), otherwise the application will fail using "setValue: forUndefinedKey: this class is not suitable for encoding the key for the aBool key".

Example: Here is how my object will look in Objective-C:

@interface TestObject : NSObject @property (strong, nonatomic) NSString *aString; @property (assign, nonatomic) BOOL aBool; @property (assign, nonatomic) CGFloat aFloat; @end 

and the "equivalent" in Swift:

 class TestObject:NSObject { var aString:NSString? var aBool:Bool? var aFloat:Double? } 

What happens, and when I understand WHY it crashes, I would like to know if there is another workaround than using NSNumber for Booleans, Integer and Floats, just like it works in Objective-C?

(If any of the RestKit developers reads this: First of all, thanks for your work, and then: Are there any plans for Swift support / port for Swift?)

Answer 1

I am making an application in Swift, and we started work in the summer of 2014 when Swift was completely new. I started using RestKit to handle REST communication with the server, and I spent at least a full month setting up RestKit for my use.

Until I know your use case, it was easier for me to use Alamofire and SwiftyJSON to work. It saved me many hours. It also means that I manually do the conversion from dynamic types to object types, but the time spent on it is much less than the time I previously spent setting up RestKit.

If this is not a viable way for you, you might want to take a look at the RKValueTransformer classes available in RestKit; in your RKObjectMapping you can specify your own transformers for individual properties. But then again, I think the time is better spent on Alamofire and SwiftyJSON. After all, these are native Swift libraries.

Answer 2

For those who cannot refuse RestKit in the Swift project, this solution can be useful.

In my case, the application crashes because RestKit was not able to match the "true" / "false" strings from JSON to type Bool in Swift.

I decided to add another String attribute to my class and update the required boolean using the didSet method. In your case, it will be:

 class TestObject:NSObject { var aString:NSString? var aBool:Bool? var aFloat:Double? var aBoolString: String? { didSet { self.aBool = aBoolString.lowercased() == "true" } } } 

Hope this helps!