B4X

Download GMail Message Attachment by ID

See more GMail REST API Examples

Demonstrates how to download a GMail email attachment by the attachment ID. B4X

Dim success As Boolean = False

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

Dim http As ChilkatHttp
http.Initialize("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".
Dim attachmentId As String = "ANGjdJ-oy3aCuZISJKLAhUdaEksCEklbAPyMaWzFgqOMGbPCRkgwgeu_Kttd99C17OBTHROkDZGekibTKWXGfscB5ww7fw4E65_V1dQ-jHhb2TD1Cdm58-BbNw2iDxzptco8iILPiSnLLfFn5Ps7nsRcxHaGTt3r0yqFKCuIYNnPK1vM04BXI_cfzo-HnI4I3tD6oHNHOGVQrL01MdShFQjPELPUjXM8z1qs7Kom-QyvV1iOldUN-66UuhynsmDX-CMM5TIdB-8KD_lmdhf-0DqG8JnCA20XpXyfqwS8XFkPA-t-QSjb7SdkHQFtQ4lz2PcBREFzZ2eI5j0l0Y_dQHRPYTeMwkVl1yl4MfFT4C4iso3VSF-eqaIjiFCbXKCFNyeEIW5WFsv189dhlSqU"

Dim messageId As String = "1712bc1dc22da2a2"

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

Dim url As String = "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=="
'  }

Dim outputFilePath As String = "qa_output/helloWorld.pdf"

'  Download into a StringBuilder.
Dim sbJson As ChilkatStringBuilder
sbJson.Initialize
success = http.DownloadSb(url, "utf-8", sbJson)
If success = False Then
    Log(http.LastErrorText)
    Return
End If


If http.LastStatus <> 200 Then
    '  Something failed.
    '  the JSON contains an error message.
    Log(sbJson.GetAsString)
    Return
End If


'  Load into a Chilkat JSON object.
Dim json As ChilkatJsonObject
json.Initialize
success = json.LoadSb(sbJson)

'  Extract the base64url data into a BinData.
Dim bd As ChilkatBinData
bd.Initialize
success = json.BytesOf("data", "base64url", bd)

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

Log("Success.")