(Swift 3,4,5...) Google Drive - Resumable Upload

Demonstrates how to do a resumable upload to Google Drive.

For more information, see https://developers.google.com/drive/api/v3/manage-uploads#resumable

Chilkat Downloads for the Swift Programming Language MAC OS X (Cocoa) Objective-C/Swift Libs iOS Objective-C/Swift Libs

func chilkatTest() {
    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    var success: Bool = true

    // This example uses a previously obtained access token having permission for the 
    // Google Drive scope. 
    // See Get Google Drive OAuth2 Access Token

    let http = CkoHttp()!

    http.authToken = "GOOGLE_DRIVE_ACCESS_TOKEN"

    // First we want to initiate the resumable upload.
    // We send a POST to get a session URI, which will be used to upload the file, and resume if needed.

    // Our POST will look like this:

    // POST https://www.googleapis.com/upload/drive/v3/files?uploadType=resumable HTTP/1.1
    // Authorization: Bearer [YOUR_AUTH_TOKEN]          <-- Chilkat automatically adds this header because the AuthToken property was set.
    // Content-Length: 38                               <-- Chilkat will automatically add this header.
    // Content-Type: application/json; charset=UTF-8    <-- This is the type of this POST, and is specified in the call to PostJson3.
    // X-Upload-Content-Type: application/zip           <-- The type of file we'll be uploading
    // X-Upload-Content-Length: 1366807                 <-- The size of the file we'll be uploading
    // 
    // {
    //   "name": "myObject"
    // }

    http.setRequestHeader("X-Upload-Content-Type", value: "application/zip")
    http.setRequestHeader("X-Upload-Content-Length", value: "1366807")

    let json = CkoJsonObject()!
    json.update("name", value: "myZip")

    var resp: CkoHttpResponse? = http.postJson3("https://www.googleapis.com/upload/drive/v3/files?uploadType=resumable", contentType: "application/json", json: json)
    if http.lastMethodSuccess == false {
        print("\(http.lastErrorText!)")
        return
    }

    var statusCode: Int = resp!.statusCode.intValue
    if statusCode != 200 {
        print("\(resp!.bodyStr!)")
        print("response status = \(statusCode)")
        return
    }

    // The session URI is in the "Location" response header:
    let sbSessionUri = CkoStringBuilder()!
    sbSessionUri.append(resp!.getHeaderField("Location"))
    var sessionUri: String? = sbSessionUri.getAsString()
    print("Session URI: \(sessionUri!)")

    resp = nil

    // Here's a sample session URI:  https://www.googleapis.com/upload/drive/v3/files?uploadType=resumable&upload_id=AEnB2UrszR8lDqlo3mtXJw_0rYI_Hi1oVh1NPFcLfoyBq9NcSjk85kFopoZaVEgT38OSmLl0XsObPf4iCSJwHlrOvvIJQ_ckIQ

    // -----------------------------------------------------------------------------
    // The next step is to upload the file using the session URI:

    // We'll send a PUT that looks like this:

    // PUT https://www.googleapis.com/upload/drive/v3/files?uploadType=resumable&upload_id=xa298sd_sdlkj2 HTTP/1.1
    // Content-Length: 1366807
    // Content-Type: application/zip
    // 
    // [BYTES 0-1366806]

    // First remove the X-Upload-Content-Type and X-Upload-Content-Length request headers we specified earlier, so they don't get sent with subsequent requests.
    http.clearHeaders()

    // Because the file is likely large, we'll use SynchronousRequest which allows to to pass an HTTP request object where the body can be streamed directly from a file.
    let req = CkoHttpRequest()!

    req.contentType = "application/zip"
    req.httpVerb = "PUT"

    let url = CkoUrl()!
    url.parseUrl(sessionUri)

    req.path = url.pathWithQueryParams
    print("Path with Query Param: \(url.pathWithQueryParams!)")

    // Specify that the request body is to be streamed directly from a file.
    success = req.streamBody(fromFile: "qa_data/zips/big.zip")
    if success == false {
        print("\(req.lastErrorText!)")
        return
    }

    resp = http.synchronousRequest(url.host, port: url.port.intValue, ssl: url.ssl, req: req)
    if http.lastMethodSuccess == false {
        print("\(http.lastErrorText!)")
        return
    }

    print("\(resp!.bodyStr!)")
    print("response status = \(statusCode)")

    // Sample output:

    // {
    //  "kind": "drive#file",
    //  "id": "1rx20i53eurtkVQ-RT7Ry8Ct85PgPYMET",
    //  "name": "myZip",
    //  "mimeType": "application/zip"
    // }
    // 
    // response status = 200

    resp = nil

}