Observable+Genome.swift

import Foundation
import RxSwift
import Genome
import PureJsonSerializer

enum JsonError: String {
    case CouldNotParseJSON
}

extension JsonError: ErrorType { }

extension Observable {
    
    typealias Dictionary = [String: AnyObject]
    
    /// Get given JSONified data, pass back objects
    func mapToObject<B: MappableObject>(classType: B.Type) -> Observable<B> {
        return self.map { json in
            guard let dict = json as? Dictionary else {
                throw JsonError.CouldNotParseJSON
            }
            return try B.newInstance(Json.from(dict))
        }
    }
    
    /// Get given JSONified data, pass back objects as an array
    func mapToObjectArray<B: MappableObject>(classType: B.Type) -> Observable<[B]> {
        return self.map { json in
            guard let array = json as? [AnyObject] else {
                throw JsonError.CouldNotParseJSON
            }
            
            guard let dicts = array as? [Dictionary] else {
                throw JsonError.CouldNotParseJSON
            }
            
            return  dicts.flatMap { json -> B? in
                do {
                    return try B.newInstance(Json.from(json))
                } catch {
                    return nil
                }
            }
        }
    }
}