(PureBasic) 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 PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkBinData.pb"
IncludeFile "CkHttp.pb"
IncludeFile "CkStringBuilder.pb"
IncludeFile "CkJsonObject.pb"

Procedure ChilkatExample()

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

    http.i = CkHttp::ckCreate()
    If http.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success.i

    CkHttp::setCkAuthToken(http, "ACCESS_TOKEN")
    CkHttp::setCkAccept(http, "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.s = "ANGjdJ-oy3aCuZISJKLAhUdaEksCEklbAPyMaWzFgqOMGbPCRkgwgeu_Kttd99C17OBTHROkDZGekibTKWXGfscB5ww7fw4E65_V1dQ-jHhb2TD1Cdm58-BbNw2iDxzptco8iILPiSnLLfFn5Ps7nsRcxHaGTt3r0yqFKCuIYNnPK1vM04BXI_cfzo-HnI4I3tD6oHNHOGVQrL01MdShFQjPELPUjXM8z1qs7Kom-QyvV1iOldUN-66UuhynsmDX-CMM5TIdB-8KD_lmdhf-0DqG8JnCA20XpXyfqwS8XFkPA-t-QSjb7SdkHQFtQ4lz2PcBREFzZ2eI5j0l0Y_dQHRPYTeMwkVl1yl4MfFT4C4iso3VSF-eqaIjiFCbXKCFNyeEIW5WFsv189dhlSqU"

    messageId.s = "1712bc1dc22da2a2"

    CkHttp::ckSetUrlVar(http,"messageId",messageId)
    CkHttp::ckSetUrlVar(http,"attachmentId",attachmentId)

    url.s = "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.s = "qa_output/helloWorld.pdf"

    ; Download into a StringBuilder.
    sbJson.i = CkStringBuilder::ckCreate()
    If sbJson.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkHttp::ckDownloadSb(http,url,"utf-8",sbJson)
    If success = 0
        Debug CkHttp::ckLastErrorText(http)
        CkHttp::ckDispose(http)
        CkStringBuilder::ckDispose(sbJson)
        ProcedureReturn
    EndIf

    If CkHttp::ckLastStatus(http) <> 200
        ; Something failed.
        ; the JSON contains an error message.
        Debug CkStringBuilder::ckGetAsString(sbJson)
        CkHttp::ckDispose(http)
        CkStringBuilder::ckDispose(sbJson)
        ProcedureReturn
    EndIf

    ; Load into a Chilkat JSON object.
    json.i = CkJsonObject::ckCreate()
    If json.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkJsonObject::ckLoadSb(json,sbJson)

    ; Extract the base64url data into a BinData.
    bd.i = CkBinData::ckCreate()
    If bd.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkJsonObject::ckBytesOf(json,"data","base64url",bd)

    ; Save the data to a file.
    success = CkBinData::ckWriteFile(bd,"qa_output/helloWorld.pdf")

    Debug "Success."


    CkHttp::ckDispose(http)
    CkStringBuilder::ckDispose(sbJson)
    CkJsonObject::ckDispose(json)
    CkBinData::ckDispose(bd)


    ProcedureReturn
EndProcedure