A set of classes/extensions to abstract the parse logic and also using a Result enum to pass data around

Parse Layer

public extension PFCloud {
	
	public class func fetchObjectFromCloud<T>(functionName: String, parameters: [NSObject: AnyObject] = [:], completion: NetworkResponse<T>->Void) {
		PFCloud.callFunctionInBackground(functionName, withParameters: parameters) { result, error in
			if let error = error {
				completion(NetworkResponse.Failure(error))
			}
			else {
				completion(NetworkResponse.Success(result![0] as! T))
			}
		}
	}
	
	public class func fetchObjectsFromCloud<T>(functionName: String, parameters: [NSObject: AnyObject] = [:], completion: NetworkResponse<[T]>->Void) {
		PFCloud.callFunctionInBackground(functionName, withParameters: parameters) { result, error in
			if let error = error {
				completion(NetworkResponse.Failure(error))
			}
			else {
				let array = result as! [AnyObject]
				completion(NetworkResponse.Success(array.map { $0 as! T } ))
			}
		}
	}
}



public extension PFQuery {

	public func findObjectsInBackgroundWithCompletion <T> (completion: NetworkResponse<[T]>->Void) {
		findObjectsInBackgroundWithBlock { result, error in
			if let error = error {
				completion(NetworkResponse.Failure(error))
			}
			else {
				completion(NetworkResponse.Success(result!.map { $0 as! T }))
			}
		}
	}
	
	public func findObjectInBackgroundWithCompletion <T> (completion: NetworkResponse<T>->Void) {
		findObjectsInBackgroundWithBlock { result, error in
			if let error = error {
				completion(NetworkResponse.Failure(error))
			}
			else {
				if result!.count == 1 {
					completion(NetworkResponse.Success(result![0] as! T))
				}
				else if result!.count == 0 {
					completion(NetworkResponse.Failure(NetworkError.NoRecordsFound))
				}
				else {
					completion(NetworkResponse.Failure(NetworkError.MultipleRecordsFound))
				}
			}
		}
	}
	
	public func fetchObjectWithId<T>(id: String, completion: NetworkResponse<T>->Void) {
		getObjectInBackgroundWithId(id) { object, error in
			if let error = error {
				completion(NetworkResponse.Failure(error))
			}
			else {
				completion(NetworkResponse.Success(object as! T))
			}
		}
	}
}


public enum NetworkError: ErrorType {
	case MultipleRecordsFound
	case NoRecordsFound
}


public enum NetworkResponse<T> {

	case Success(T)
	case Failure(ErrorType)
	
	public var hasError: Bool {
		switch self {
		case .Success(_):
				return false
		case .Failure(_):
				return true
		}
	}
	
	public var result: T? {
		if case .Success(let data) = self {
			return data
		}
		
		return Optional.None
	}
	
	public var error: ErrorType? {
		if case .Failure(let error) = self {
			return error
		}
		
		return nil
	}
	
}