(Visual FoxPro) 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 ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

LOCAL lnSuccess
LOCAL loHttp
LOCAL loJson
LOCAL loResp
LOCAL lnStatusCode
LOCAL loSbSessionUri
LOCAL lcSessionUri
LOCAL loReq
LOCAL loUrl

* This example requires the Chilkat API to have been previously unlocked.
* See Global Unlock Sample for sample code.

lnSuccess = 1

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

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Http')
loHttp = CreateObject('Chilkat.Http')

loHttp.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"
* }

loHttp.SetRequestHeader("X-Upload-Content-Type","application/zip")
loHttp.SetRequestHeader("X-Upload-Content-Length","1366807")

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.JsonObject')
loJson = CreateObject('Chilkat.JsonObject')
loJson.UpdateString("name","myZip")

loResp = loHttp.PostJson3("https://www.googleapis.com/upload/drive/v3/files?uploadType=resumable","application/json",loJson)
IF (loHttp.LastMethodSuccess = 0) THEN
    ? loHttp.LastErrorText
    RELEASE loHttp
    RELEASE loJson
    CANCEL
ENDIF

lnStatusCode = loResp.StatusCode
IF (lnStatusCode <> 200) THEN
    ? loResp.BodyStr
    ? "response status = " + STR(lnStatusCode)
    RELEASE loHttp
    RELEASE loJson
    CANCEL
ENDIF

* The session URI is in the "Location" response header:
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.StringBuilder')
loSbSessionUri = CreateObject('Chilkat.StringBuilder')
loSbSessionUri.Append(loResp.GetHeaderField("Location"))
lcSessionUri = loSbSessionUri.GetAsString()
? "Session URI: " + lcSessionUri

RELEASE loResp

* 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.
loHttp.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.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.HttpRequest')
loReq = CreateObject('Chilkat.HttpRequest')

loReq.ContentType = "application/zip"
loReq.HttpVerb = "PUT"

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Url')
loUrl = CreateObject('Chilkat.Url')
loUrl.ParseUrl(lcSessionUri)

loReq.Path = loUrl.PathWithQueryParams
? "Path with Query Param: " + loUrl.PathWithQueryParams

* Specify that the request body is to be streamed directly from a file.
lnSuccess = loReq.StreamBodyFromFile("qa_data/zips/big.zip")
IF (lnSuccess = 0) THEN
    ? loReq.LastErrorText
    RELEASE loHttp
    RELEASE loJson
    RELEASE loSbSessionUri
    RELEASE loReq
    RELEASE loUrl
    CANCEL
ENDIF

loResp = loHttp.SynchronousRequest(loUrl.Host,loUrl.Port,loUrl.Ssl,loReq)
IF (loHttp.LastMethodSuccess = 0) THEN
    ? loHttp.LastErrorText
    RELEASE loHttp
    RELEASE loJson
    RELEASE loSbSessionUri
    RELEASE loReq
    RELEASE loUrl
    CANCEL
ENDIF

? loResp.BodyStr
? "response status = " + STR(lnStatusCode)

* Sample output:

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

RELEASE loResp

RELEASE loHttp
RELEASE loJson
RELEASE loSbSessionUri
RELEASE loReq
RELEASE loUrl