(Visual Basic 6.0) Get GMail Message Metadata

Demonstrates how to get the metadata for each message in a list of message IDs.

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

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

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

Dim http As New ChilkatHttp

http.AuthToken = "ACCESS_TOKEN"

http.Accept = "application/json"

' Let's say we have the following JSON containing a list of message ID's

' {
'   "messages": [
'     {
'       "id": "1712bc1dc22da2a2",
'       "threadId": "1712bc1dc22da2a2"
'     },
'     {
'       "id": "1712b94fa2168040",
'       "threadId": "1712b94fa2168040"
'     },
'     {
'       "id": "1711e4bd96ded05e",
'       "threadId": "1711e4bd96ded05e"
'     },
'     {
'       "id": "1711de0d119e751e",
'       "threadId": "1711de0d119e751e"
'     },
'     {
'       "id": "1711c81a43050f59",
'       "threadId": "1711c81a43050f59"
'     },
'     {
'       "id": "1711c2c1516abce5",
'       "threadId": "1711c2c1516abce5"
'     },
'     {
'       "id": "1711c161e655c915",
'       "threadId": "1711c161e655c915"
'     },
'     {
'       "id": "171199c6e454558c",
'       "threadId": "171199c6e454558c"
'     },
'     {
'       "id": "17119474c8aa248e",
'       "threadId": "17119474c8aa248e"
'     }
'   ],
'   "nextPageToken": "16710921492249671162",
'   "resultSizeEstimate": 309
' }

' Normally your program would have the above JSON in a string variable (obtained from a previous call to get
' a list of message IDs from a GMail mailbox).  In this example, we'll load the JSON from a file.
Dim jsonMsgIds As New ChilkatJsonObject
Dim success As Long
success = jsonMsgIds.LoadFile("qa_data/json/gmail_message_ids.json")

Dim id As String
Dim i As Long
i = 0
Dim count_i As Long
count_i = jsonMsgIds.SizeOfArray("messages")
Do While i < count_i
    jsonMsgIds.I = i
    id = jsonMsgIds.StringOf("messages[i].id")

    ' Get the metadata for this message ID.
    success = http.SetUrlVar("id",id)

    Dim resp As ChilkatHttpResponse
    Set resp = http.QuickRequest("GET","https://www.googleapis.com/gmail/v1/users/userId/messages/{$id}?format=metadata")
    If (http.LastMethodSuccess <> 1) Then
        Debug.Print http.LastErrorText
        Exit Sub
    End If

    Debug.Print "Response Status Code: " & resp.StatusCode

    Dim jsonResponse As New ChilkatJsonObject
    success = jsonResponse.Load(resp.BodyStr)
    jsonResponse.EmitCompact = 0
    Debug.Print jsonResponse.Emit()

    If (resp.StatusCode <> 200) Then
        Debug.Print "Failed."

        Exit Sub
    End If

    i = i + 1
Loop

' Use this online tool to generate parsing code from sample JSON: 
' Generate Parsing Code from JSON