VBScript
Download GMail Message Attachment by ID

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

VBScript
Dim fso, outFile
Set fso = CreateObject("Scripting.FileSystemObject")
'Create a Unicode (utf-16) output text file.
Set outFile = fso.CreateTextFile("output.txt", True, True)

success = 0

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

set http = CreateObject("Chilkat.Http")

http.AuthToken = "ACCESS_TOKEN"
http.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".
attachmentId = "ANGjdJ-oy3aCuZISJKLAhUdaEksCEklbAPyMaWzFgqOMGbPCRkgwgeu_Kttd99C17OBTHROkDZGekibTKWXGfscB5ww7fw4E65_V1dQ-jHhb2TD1Cdm58-BbNw2iDxzptco8iILPiSnLLfFn5Ps7nsRcxHaGTt3r0yqFKCuIYNnPK1vM04BXI_cfzo-HnI4I3tD6oHNHOGVQrL01MdShFQjPELPUjXM8z1qs7Kom-QyvV1iOldUN-66UuhynsmDX-CMM5TIdB-8KD_lmdhf-0DqG8JnCA20XpXyfqwS8XFkPA-t-QSjb7SdkHQFtQ4lz2PcBREFzZ2eI5j0l0Y_dQHRPYTeMwkVl1yl4MfFT4C4iso3VSF-eqaIjiFCbXKCFNyeEIW5WFsv189dhlSqU"

messageId = "1712bc1dc22da2a2"

success = http.SetUrlVar("messageId",messageId)
success = http.SetUrlVar("attachmentId",attachmentId)

url = "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=="
' }

outputFilePath = "qa_output/helloWorld.pdf"

' Download into a StringBuilder.
set sbJson = CreateObject("Chilkat.StringBuilder")
success = http.DownloadSb(url,"utf-8",sbJson)
If (success = 0) Then
    outFile.WriteLine(http.LastErrorText)
    WScript.Quit
End If

If (http.LastStatus <> 200) Then
    ' Something failed.
    ' the JSON contains an error message.
    outFile.WriteLine(sbJson.GetAsString())
    WScript.Quit
End If

' Load into a Chilkat JSON object.
set json = CreateObject("Chilkat.JsonObject")
success = json.LoadSb(sbJson)

' Extract the base64url data into a BinData.
set bd = CreateObject("Chilkat.BinData")
success = json.BytesOf("data","base64url",bd)

' Save the data to a file.
success = bd.WriteFile("qa_output/helloWorld.pdf")

outFile.WriteLine("Success.")

outFile.Close