Alamofire Use of undeclared type 'Serializer'

Question

I have updated to XCode 7 beta 6 and Alamofire needed to be updated to beta 3. In doing so, I'm having to update areas of the code that use Alamofire. One area in particular that I'm having difficulty updating is the code which is used to retrieve an image from a specified URL and load it into a UIImageView.

Previously, the extension for Alamofire that handled that was:

extension Alamofire.Request {
    class func imageResponseSerializer() -> Serializer {
        return { request, response, data in
            if data == nil {
                return (nil, nil)
            }

            let image = UIImage(data: data!, scale: UIScreen.mainScreen().scale)

            return (image, nil)
        }
    }

    func responseImage(completionHandler: (NSURLRequest, NSHTTPURLResponse?, UIImage?, NSError?) -> Void) -> Self {
        return response(serializer: Request.imageResponseSerializer(), completionHandler: { (request, response, image, error) in
            completionHandler(request!, response, image as? UIImage, error)
        })
    }
}

But not that is throwing the error

Use of undeclared type 'Serializer'

I do realize that Alamofire doesn't use Serializer anymore, but does anyone know where I can find some documentation or examples what to do now when retrieving images?

Answer 1

正如您在自述文件中所发现的那样，序列化被重写。

您可以使用以下方法：

public protocol ResponseObjectSerializable {
    init?(response: NSHTTPURLResponse, representation: AnyObject)
}

extension Request {
    public func responseObject<T: ResponseObjectSerializable>(completionHandler: Response<T, NSError> -> Void) -> Self {
        let responseSerializer = ResponseSerializer<T, NSError> { request, response, data, error in
            guard error == nil else { return .Failure(error!) }

            let JSONResponseSerializer = Request.JSONResponseSerializer(options: .AllowFragments)
            let result = JSONResponseSerializer.serializeResponse(request, response, data, error)

            switch result {
            case .Success(let value):
                if let
                    response = response,
                    responseObject = T(response: response, representation: value)
                {
                    return .Success(responseObject)
                } else {
                    let failureReason = "JSON could not be serialized into response object: \(value)"
                    let error = Error.errorWithCode(.JSONSerializationFailed, failureReason: failureReason)
                    return .Failure(error)
                }
            case .Failure(let error):
                return .Failure(error)
            }
        }

        return response(responseSerializer: responseSerializer, completionHandler: completionHandler)
    }
}

Answer 2

Alamofire的UIImage序列化器，针对Alamofire 2.0和Swift 2进行了更新

Alamofire 2.0 and Swift 2.0