Download File Using Alamofire 4.0 (Swift 3)

Question

In older version of Alamofire. This is how I download file

    let destinationPath = Alamofire.Request.suggestedDownloadDestination( directory: .documentDirectory, domain: .userDomainMask);

    Alamofire.download(.GET, urlString, destination: destinationPath)
        .progress { bytesRead, totalBytesRead, totalBytesExpectedToRead in
//                print(totalBytesRead)
        }
        .response { request, response, _, error in

            let downloadedFilePath = destinationPath(URL(string: "")!, response!);

            NSUserDefaultsHelper.saveURL(downloadedFilePath, key: urlString);

            completion(downloadedFilePath, true);
    }

But now in the new version, my code is completely unusable and there is no similar function in the Alamofire library.

Any ideas please?

Solution 1

I used to use this statements:

let destination = DownloadRequest.suggestedDownloadDestination(for: .documentDirectory)

Alamofire.download(
    url,
    method: .get,
    parameters: parameters,
    encoding: JSONEncoding.default,
    headers: nil,
    to: destination).downloadProgress(closure: { (progress) in
        //progress closure
    }).response(completionHandler: { (DefaultDownloadResponse) in
        //here you able to access the DefaultDownloadResponse
        //result closure
    })

For more details read more in Alamofire docs about Migration to 4.0:

Solution 2

Swift 4.0

 let destination: DownloadRequest.DownloadFileDestination = { _, _ in
            var documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
            documentsURL.appendPathComponent("file.csv")
            return (documentsURL, [.removePreviousFile])
        }

        Alamofire.download(url, to: destination).responseData { response in
            if let destinationUrl = response.destinationURL {
               print("destinationUrl \(destinationUrl.absoluteURL)")
            }
        }

Solution 3

There are several enhancements in Alamofire 4. The first of which is the optionality of the destination closure. Now, by default, the destination closure is nil which means the file is not moved anywhere on the file system and the temporary URL is returned.

This is the default execution:-

Alamofire.download(urlString).responseData { response in
    print("Temporary URL: \(response.temporaryURL)")
}

This is my code to download file with Alamofire 4.0 which return destination Url of file:-

let destination: DownloadRequest.DownloadFileDestination = { _, _ in
        var documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
        documentsURL.appendPathComponent("duck.png")
        return (documentsURL, [.removePreviousFile])
    }

    Alamofire.download(url, to: destination).responseData { response in
    if let destinationUrl = response.destinationURL ? {
        completionHandler(destinationUrl)
    }
}

Solution 4

Downloading mp3 file with Alamofire 4.0 Swift 4.x

Since almost all samples seems to be about downloading an image or a JSON file, it took me hours to find the right solution.
I will share it here hoping it would help others to save some time.

func startDownload(audioUrl:String) -> Void {
    let fileUrl = self.getSaveFileUrl(fileName: audioUrl)
    let destination: DownloadRequest.DownloadFileDestination = { _, _ in
        return (fileUrl, [.removePreviousFile, .createIntermediateDirectories])
    }

    Alamofire.download(audioUrl, to:destination)
        .downloadProgress { (progress) in
            self.progressLabel.text = (String)(progress.fractionCompleted)
        }
        .responseData { (data) in
            self.progressLabel.text = "Completed!"
    }
}

func getSaveFileUrl(fileName: String) -> URL {
    let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
    let nameUrl = URL(string: fileName)
    let fileURL = documentsURL.appendingPathComponent((nameUrl?.lastPathComponent)!)
    NSLog(fileURL.absoluteString)
    return fileURL;
}

Solution 5

For the latest versions this is how it should look like:

let destination: DownloadRequest.Destination = { _, _ in
        let documentsURL = FileManager.default.urls(for: .picturesDirectory, in: .userDomainMask)[0]
            let fileURL = documentsURL.appendingPathComponent("image.png")

            return (fileURL, [.removePreviousFile, .createIntermediateDirectories])
    }

    AF.download("https://httpbin.org/image/png", to: destination).response { response in
        debugPrint(response)

        if response.error == nil, let imagePath = response.fileURL?.path {
            let image = UIImage(contentsOfFile: imagePath)
        }
    }

View more solutions

Comments

[JayVDiyk]

The code block inside the response is DefaultDownloadResponse, I am having problem in getting the final 'downloadedFilePath'

[pedrouan]

The actual downloaded file path is destination + nameOfTheFile, isn't it?

[JayVDiyk]

yes, but if you look at my code, the file name is generated automatically by Alamofire. That is why I used the destinationPath function to get the full path.

[pedrouan]

I may misunderstood. An answer updated. Is this what you are looking for?

[Dumitru Rogojinaru]

i am sorry, but I am now in programming, I have downloaded an audio file, how do I get the url Path where it's saved correctly, in order to play the sound? thanks

[ami rt]

why you use documentsURL, [.removePreviousFile]

[Praburaj]

Can anyone tell how to open the file using the destination url after the file has been downloaded..

[Gene Z. Ragan]

DefaultDownloadResponse.destinationURL contains the url to the downloaded data

[Monish]

how can i get parameters in completionHandler ?

[famfamfam]

Hi. I downloaded success but can not find where is my video, can u help?

[Pankaj Jangid]

@famfamfam you can find the file in document directory

[famfamfam]

Hi. here is my file url : 'file:///Users/thehe/Library/Developer/CoreSimulator/Devices‌​/01F3C177-1B6A-4CB4-‌​AABE-45EB0D57A3C1/da‌​ta/Containers/Data/A‌​pplication/DEA4544E-‌​54A9-4104-9A7A-CAF5B‌​9D172B3/Documents/Ci‌​viX_HistoryVideo_19-‌​1-2019_7h59m28s.mp4' , then my error i got is 'The file “CiviX_HistoryVideo_19-1-2019_7h59m28s.mp4” couldn’t be saved in the folder “Documents”.'

[Pankaj Jangid]

@famfamfam please check progress rate, If it is 100% then It will be saved into document directory