Swift API v2 Example of uploading a file using filesUploadSession(Start, Append, Finish)

I don't think we have a full sample using that published, but here's a very simple example I just put together: (apologies for the atrocious code formatting on the forum)

        // Write a file to the local documents directory

        let text = "Hello world. Usually something much longer here."

        let filename = "working-draft.txt"

        let localDir = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0] as String

        let localPath = localDir.stringByAppendingString(filename)

        try! text.writeToFile(localPath, atomically:true, encoding:NSUTF8StringEncoding)

        let fileURL = NSURL.fileURLWithPath(localPath)

        let fileLength = UInt64(text.lengthOfBytesUsingEncoding(NSUTF8StringEncoding))

        print(fileURL)

        print(fileLength)

        // start the upload session, passing along the NSURL to the whole file in this case, since it's small

        // there are also versions that take NSData or NSInputStream as the body

        client.filesUploadSessionStart(body: fileURL).response { response, error in

            if let result = response {

                // the call succeeded

                print(result)

                // also call filesUploadSessionAppend to add more data if/as necessary, as many times as necessary (be sure to track the offset)

                // we're ready to finish the upload and commit the file

                client.filesUploadSessionFinish(cursor: Files.UploadSessionCursor(sessionId: result.sessionId, offset: fileLength),

                                                commit: Files.CommitInfo(path: "/test_swift_upload_session.txt"),

                                                // no additional data to add at this point in this case

                                                body:NSData()).response { response, error in

                                                    if let result = response {

                                                        print(result)

                                                    } else {

                                                        print(error!)

                                                    }

                }

            } else {

                // the call failed

                print(error!)

            }

        }

If I try to load a 1GB files with a Stream input  using  filesUploadSessionStart  will the file get completely uploaded by the time it calls the response ? 

If not how do I find how much was transferred so I know where to start with subsequent filesUploadSessionAppend ... that's the part I am missing.

Each call to filesUploadSessionStart, filesUploadSessionAppend, or filesUploadSessionFinish uploads all of the data you give to it. So in your case, if you supply 1 GB, it will attempt to upload all of that data at once, before response is called. That will likely fail though, so you should instead only upload a piece at a time. E.g., you could use chunks of 4 MB, where you supply 4 MB to start, another 4 MB to append repeatedly as necessary, and then the remainder to finish.

Is there a reason why filesUploadSessionAppend takes an offset and Session ID and filesUploadSessionFinish takes a Files.UploadSessionCursor which wraps the Offset and Session ID ?

Seems like these calls should hava a similar calling convention except that SessionFinsish should have the extra  CommitInfo

Actually I think the API would be cleaner with a smple

   SessionStart -- NO Data just return the SessonID

   SessionAppend   Args would be SessionID, Data, and Offset

   SessionFinish     Args would be SessionID and Completion

Adding a data transfer to the SessionStart and SessionFinish makes the interface much more clunky ... and all you have saved is possibly one small packet transfer. You Currently need minimally 2 requests (Start and Finish), one can be small. With a cleaner interface you would need minimally 3 requests, two are small.

Thanks for the feedback! I don't know off hand why append and finish are different, but I'll be sure to pass this along.