NSErrorType protocol

NSErrorType.swift

// ----------------------------------------------------------------------
// MARK: NSErrorType protocol, with JSON extensions for NSError
// ----------------------------------------------------------------------

/** so if you have a ErrorType var, and you want to test for NSError ex (e is NSError), it always succeeds.
it can sometimes be hard to test for NSError.
but you can test for protocol conformance.
so now:

    e as? NSErrorType

will only succeed is e is actually NSError.
this shortcircuits the built in Swift 2 ErrorType to NSError conversion
*/
public protocol NSErrorType {
    var userInfo: [NSObject : AnyObject] { get }
    var domain: String { get }
    var code: Int { get }
}


extension NSError : NSErrorType {
    convenience init(error : ErrorType, jsonData : JSON) {
        let e = error as NSError
        var newUserInfo = e.userInfo
        newUserInfo[SquarespaceServerErrorDataKey] = jsonData.object
        self.init(domain: e.domain, code: e.code, userInfo:newUserInfo)
    }
}

public extension NSErrorType {
    var jsonData : JSON? {
        get {
            if let rawObject = self.userInfo[SquarespaceServerErrorDataKey] {
                return JSON(rawObject)
            }
            else {
                return nil
            }
        }
    }
}