Alamofire JSONSerializable Extensions

AlamofireExtensions.swift

import Foundation
import Alamofire
import SwiftyJSON

typealias AlamofireResponseCompletion = (NSURLRequest, NSHTTPURLResponse?, AnyObject?, NSError?) -> Void

private let QueueIdentifier: String = "com.alamofire.Alamofire.SerializationQueue"
private let ErrorDomain: String = "com.alamofire.Alamofire.responseJSONSerializable"

// MARK: - Serializer for the API

internal extension Alamofire.Request {
    func responseJSONSerializableCollection<T: JSONSerializable>(completionHandler: ((NSURLRequest, NSHTTPURLResponse?, [T]?, Int?, NSError?) -> Void)) -> Self {
        let serializationQueue = dispatch_queue_create(QueueIdentifier, DISPATCH_QUEUE_SERIAL)
        
        return responseSwiftyJSON(queue: serializationQueue, options: .MutableContainers, completionHandler: { request, response, JSON, error in
            var objects: [T] = []
            var requestError: NSError?
            
            if error != nil {
                let APIError = Error(json: JSON)
                var userInfo = error?.userInfo ?? [:]
                userInfo["APIError"] = APIError
                
                requestError = NSError(domain: ErrorDomain, code: error?.code ?? -1, userInfo: userInfo)
            } else {
                if let collection = JSON.array {
                    objects = collection.map { T(json: $0) }
                }
            }
            
            dispatch_async(dispatch_get_main_queue()) {
                completionHandler(request, response, objects, -1, requestError)
            }
        })
    }
    
    func responseJSONSerializable<T: JSONSerializable>(completionHandler: ((NSURLRequest, NSHTTPURLResponse?, T?, NSError?) -> Void)) -> Self {
        let serializationQueue = dispatch_queue_create(QueueIdentifier, DISPATCH_QUEUE_SERIAL)
        
        return responseSwiftyJSON(queue: serializationQueue, options: .MutableContainers, completionHandler: { request, response, JSON, error in
            var object: T?
            var requestError: NSError?
            
            if error != nil {
                let APIError = Error(json: JSON)
                var userInfo = error?.userInfo ?? [:]
                userInfo["APIError"] = APIError
                
                requestError = NSError(domain: ErrorDomain, code: error?.code ?? -1, userInfo: userInfo)
            } else {
                object = T(json: JSON)
            }
            
            dispatch_async(dispatch_get_main_queue()) {
                completionHandler(request, response, object, requestError)
            }
        })
    }
}

// MARK: - Serializer for Swifty JSON

extension Alamofire.Request {
    
    /**
    Adds a handler to be called once the request has finished.
    
    :param: completionHandler A closure to be executed once the request has finished. The closure takes 4 arguments: the URL request, the URL response, if one was received, the SwiftyJSON enum, if one could be created from the URL response and data, and any error produced while creating the SwiftyJSON enum.
    
    :returns: The request.
    */
    internal func responseSwiftyJSON(completionHandler: (NSURLRequest, NSHTTPURLResponse?, SwiftyJSON.JSON, NSError?) -> Void) -> Self {
        return responseSwiftyJSON(queue: nil, options: NSJSONReadingOptions.AllowFragments, completionHandler: completionHandler)
    }
    
    /**
    Adds a handler to be called once the request has finished.
    
    :param: queue The queue on which the completion handler is dispatched.
    :param: options The JSON serialization reading options. `.AllowFragments` by default.
    :param: completionHandler A closure to be executed once the request has finished. The closure takes 4 arguments: the URL request, the URL response, if one was received, the SwiftyJSON enum, if one could be created from the URL response and data, and any error produced while creating the SwiftyJSON enum.
    
    :returns: The request.
    */
    internal func responseSwiftyJSON(queue: dispatch_queue_t? = nil, options: NSJSONReadingOptions = .AllowFragments, completionHandler: (NSURLRequest, NSHTTPURLResponse?, JSON, NSError?) -> Void) -> Self {
        
        return response(queue: queue, serializer: Alamofire.Request.JSONResponseSerializer(options: options), completionHandler: { (request, response, object, error) -> Void in
            
            dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), {
                
                var responseJSON: JSON
                if object == nil {
                    responseJSON = JSON.nullJSON
                } else {
                    responseJSON = SwiftyJSON.JSON(object!)
                }
                
                dispatch_async(queue ?? dispatch_get_main_queue(), {
                    completionHandler(self.request, self.response, responseJSON, error)
                })
            })
        })
    }
}