(Visual FoxPro) Download GMail Message Attachment by ID

Demonstrates how to download a GMail email attachment by the attachment ID.

For more information, see https://developers.google.com/gmail/api/v1/reference/users/messages/attachments/get

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

LOCAL loHttp
LOCAL lnSuccess
LOCAL lcAttachmentId
LOCAL lcMessageId
LOCAL lcUrl
LOCAL lcOutputFilePath
LOCAL loSbJson
LOCAL loJson
LOCAL loBd

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

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

loHttp.AuthToken = "ACCESS_TOKEN"
loHttp.Accept = "application/json"

* See the following example:  Get GMail Message (format=full)
* It shows how to download an email by message ID, and it shows how to parse the JSON
* response which includes attachment names, ids, and other information.

* This example will assume we already have the attachment id and filename.

* This is the attachment ID for a file named "helloWorld.pdf".
lcAttachmentId = "ANGjdJ-oy3aCuZISJKLAhUdaEksCEklbAPyMaWzFgqOMGbPCRkgwgeu_Kttd99C17OBTHROkDZGekibTKWXGfscB5ww7fw4E65_V1dQ-jHhb2TD1Cdm58-BbNw2iDxzptco8iILPiSnLLfFn5Ps7nsRcxHaGTt3r0yqFKCuIYNnPK1vM04BXI_cfzo-HnI4I3tD6oHNHOGVQrL01MdShFQjPELPUjXM8z1qs7Kom-QyvV1iOldUN-66UuhynsmDX-CMM5TIdB-8KD_lmdhf-0DqG8JnCA20XpXyfqwS8XFkPA-t-QSjb7SdkHQFtQ4lz2PcBREFzZ2eI5j0l0Y_dQHRPYTeMwkVl1yl4MfFT4C4iso3VSF-eqaIjiFCbXKCFNyeEIW5WFsv189dhlSqU"

lcMessageId = "1712bc1dc22da2a2"

loHttp.SetUrlVar("messageId",lcMessageId)
loHttp.SetUrlVar("attachmentId",lcAttachmentId)

lcUrl = "https://www.googleapis.com/gmail/v1/users/userId/messages/{$messageId}/attachments/{$attachmentId}"

* When we download, the response is JSON that contains the attachment data base64url encoded, like this:
* {
*  "size": 934,
*  "data": "JVBERi0xLjM ... CiUlRU9GCg=="
* }

lcOutputFilePath = "qa_output/helloWorld.pdf"

* Download into a StringBuilder.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.StringBuilder')
loSbJson = CreateObject('Chilkat.StringBuilder')
lnSuccess = loHttp.DownloadSb(lcUrl,"utf-8",loSbJson)
IF (lnSuccess = 0) THEN
    ? loHttp.LastErrorText
    RELEASE loHttp
    RELEASE loSbJson
    CANCEL
ENDIF

IF (loHttp.LastStatus <> 200) THEN
    * Something failed.
    * the JSON contains an error message.
    ? loSbJson.GetAsString()
    RELEASE loHttp
    RELEASE loSbJson
    CANCEL
ENDIF

* Load into a Chilkat JSON object.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.JsonObject')
loJson = CreateObject('Chilkat.JsonObject')
lnSuccess = loJson.LoadSb(loSbJson)

* Extract the base64url data into a BinData.
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.BinData')
loBd = CreateObject('Chilkat.BinData')
lnSuccess = loJson.BytesOf("data","base64url",loBd)

* Save the data to a file.
lnSuccess = loBd.WriteFile("qa_output/helloWorld.pdf")

? "Success."

RELEASE loHttp
RELEASE loSbJson
RELEASE loJson
RELEASE loBd