RxAlamofire+ObjectMapper.swift

//
//  Extension.swift
//
//  Created by Jasmin Suljic on 11/01/16.
//  Copyright © 2016 Leftor d.o.o. All rights reserved.
//

import Foundation
import RxSwift
import RxBlocking
import ObjectMapper
import Alamofire
import AlamofireObjectMapper

extension Request{
    public static func GenericResponseSerializer<T:Mappable>(
        keyPath: String? = nil,
        options: NSJSONReadingOptions = .AllowFragments
        )
        -> ResponseSerializer<T, NSError>
    {
        return ResponseSerializer { request, response, data, error in
            guard error == nil else {
                return .Failure(error!)
            }
            
            guard let _ = data else {
                let failureReason = "Data could not be serialized. Input data was nil."
                let error = Error.errorWithCode(.DataSerializationFailed, failureReason: failureReason)
                return .Failure(error)
            }
            
            let JSONResponseSerializer = Request.JSONResponseSerializer(options: .AllowFragments)
            let result = JSONResponseSerializer.serializeResponse(request, response, data, error)
            let JSONToMap: AnyObject?
            if let keyPath = keyPath where keyPath.isEmpty == false {
                JSONToMap = result.value?.valueForKeyPath(keyPath)
            } else {
                JSONToMap = result.value
            }
            
            if let parsedObject = Mapper<T>().map(JSONToMap){
                return .Success(parsedObject)
            }
            
            let failureReason = "ObjectMapper failed to serialize response."
            let error = Error.errorWithCode(.DataSerializationFailed, failureReason: failureReason)
            return .Failure(error)
        }
    }
}



/**
 Creates an observable of the returned decoded JSON.
 
 - parameter method: Alamofire method object
 - parameter URLString: An object adopting `URLStringConvertible`
 - parameter parameters: A dictionary containing all necessary options
 - parameter encoding: The kind of encoding used to process parameters
 - parameter header: A dictionary containing all the addional headers
 
 - returns: An observable of the decoded JSON as `T`
 */
public func JSON<T:Mappable>(method: Alamofire.Method,
    _ URLString: URLStringConvertible,
    parameters: [String: AnyObject]? = nil,
    encoding: ParameterEncoding = .URL,
    headers: [String: String]? = nil)
    -> Observable<T>
{
    return Manager.sharedInstance.rx_object(
        method,
        URLString,
        parameters: parameters,
        encoding: encoding,
        headers: headers
    )
}
extension Manager{
    /**
     Creates an observable of the data decoded from JSON and processed as `T:Mappable`.
     
     - parameter URLRequest: An object adopting `URLRequestConvertible`
     - parameter mapTo: An Type from T
     - parameter parameters: A dictionary containing all necessary options
     - parameter encoding: The kind of encoding used to process parameters
     - parameter header: A dictionary containing all the addional headers
     
     - returns: An observable of `T`
     */
    public func rx_object<T:Mappable>(method: Alamofire.Method,
        _ URLString: URLStringConvertible,
        parameters: [String: AnyObject]? = nil,
        encoding: ParameterEncoding = .URL,
        headers: [String: String]? = nil
        )
        -> Observable<T>
    {
        return rx_request(
            method,
            URLString,
            parameters: parameters,
            encoding: encoding,
            headers: headers
            ).flatMap { $0.rx_object() }
    }
}

extension Request{
    /**
     Returns an `Observable` of a serialized JSON for the current request.
     
     - parameter options: Reading options for JSON decoding process, **default:** `.AllowFragments`
     
     - returns: An instance of `Observable<T>`
     */
    public func rx_object<T:Mappable>(options: NSJSONReadingOptions = .AllowFragments) -> Observable<T> {
        return rx_result(responseSerializer: Request.GenericResponseSerializer(options: options));
    }
}

Usage example: https://gist.github.com/jasminsuljic/56a56c980d390802a144