Swift Google Drive downloading file

Question

I can't figure out how to download a Google Drive file in Swift. I followed the modified quickstart from Google Objective-C API 'GTL' with Swift and that worked. I can't translate the objective C code from the google drive API on downloading files. I've searched around and can't find anything. How can I get this to work?

Keiwan · Answer 1 · 2016-09-19T17:41:05.410

You can use this function for downloading files with the Google Drive API in Swift:

func downloadFile(file: GTLDriveFile){
    let url = "https://www.googleapis.com/drive/v3/files/\(file.identifier!)?alt=media"

    let fetcher = drive.fetcherService.fetcherWithURLString(url)

    fetcher.beginFetchWithDelegate(
        self,
        didFinishSelector: #selector(ViewController.finishedFileDownload(_:finishedWithData:error:)))
}

(In this case drive is the GTLServiceDrive - the same as in the Documentation)

Then you need to implement the function finishedFileDownload that will be called once the download is completed:

func finishedFileDownload(fetcher: GTMSessionFetcher, finishedWithData data: NSData, error: NSError?){
    if let error = error {
        //show an alert with the error message or something similar
        return
    }

    //do something with data (save it...)
}

does the file identifier change whenever the file gets modified? — bluenowhere, Dec 15 '16 at 07:47
@bluenowhere no, the same file will always have the same identifier even if you modify it for example sending an `update` request. — Keiwan, Dec 15 '16 at 09:20

score 1 · Answer 2 · answered Sep 17 '20 at 11:18

1

Actual for Swift 5.

func download(file: GTLRDrive_File) {
    let url = "https://www.googleapis.com/drive/v3/files/\(file.identifier!)?alt=media"
    let fetcher = drive.fetcherService.fetcher(withURLString: url)
    fetcher.beginFetch(completionHandler: { data, error in
        if let error = error {
            print(error.localizedDescription)
        }

        //Do something with data
    })
}

answered Sep 17 '20 at 11:18

VyacheslavBakinkskiy

1,185
9
15

This solution is not worked for me please help me if you know something about how to download drive files in swift or objective-c – Virani Vivek Oct 03 '20 at 12:13
actually my code is run but only few amount of data received but actually my file is 200 mb or more – Virani Vivek Oct 05 '20 at 09:58
Sorry, but I can't help you, I download files about 150 mb without any problems. Maybe your problem is in the network connection or something else. Try to ask new question with your code – VyacheslavBakinkskiy Oct 05 '20 at 14:38
sure, but i got the solution. it's working like charm – Virani Vivek Oct 06 '20 at 05:34

score 0 · Answer 3 · answered Jun 21 '22 at 08:03

Swift 5 with progress block. file.size returns nil for some reason so I used fetcher.response?.expectedContentLength instead.

func download(file: GTLRDrive_File, service: GTLRDriveService) {
        
    let url = "https://www.googleapis.com/drive/v3/files/\(file.identifier)?alt=media"
    let fetcher = service.fetcherService.fetcher(withURLString: url)
    fetcher.beginFetch(completionHandler: { fileData, error in
        
        if error == nil {
            
            print("finished downloading Data...")
            print(fileData as Any)
            
        
        } else {
            
            print("Error: \(String(describing: error?.localizedDescription))")
        }
    })
    
    fetcher.receivedProgressBlock = { _, totalBytesReceived in
        
        if let fileSize = fetcher.response?.expectedContentLength {
            
            let progress: Double = Double(totalBytesReceived) / Double(fileSize)
            
            // update progress bar here
            print(progress)
        }
    }
}

Swift Google Drive downloading file

3 Answers3