(VB.NET) BatchModify - Add a Label to each Message in Search Results

Searchs GMail for messages meeting a criteria and adds a label to each message found.

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

Dim success As Boolean

Dim http As New Chilkat.Http
http.AuthToken = "GMAIL-ACCESS-TOKEN"

Dim userId As String = "me"
http.SetUrlVar("userId",userId)

Dim query As String = "subject:questions"
http.SetUrlVar("query",query)

Dim url As String = "https://www.googleapis.com/gmail/v1/users/{$userId}/messages?q={$query}"

Dim sb As New Chilkat.StringBuilder
success = http.QuickGetSb(url,sb)
If (success <> True) Then
    Debug.WriteLine(http.LastErrorText)
    Exit Sub
End If


Dim json As New Chilkat.JsonObject
json.LoadSb(sb)
json.EmitCompact = False
Debug.WriteLine(json.Emit())

If (http.LastStatus <> 200) Then
    Debug.WriteLine("Failed.")
    Exit Sub
End If


' If successful, the received JSON looks like this:
' {
'   "messages": [
'     {
'       "id": "166f583051d36144",
'       "threadId": "166f583051d36144"
'     },
'     {
'       "id": "166f5815e1f36144",
'       "threadId": "166f5815e1f36144"
'     },
' 	...
'     {
'       "id": "166f580639e36144",
'       "threadId": "166f580639e36144"
'     },
'     {
'       "id": "15dbc2e28ec789c6",
'       "threadId": "15dbc2e28ec789c6"
'     }
'   ],
'   "nextPageToken": "13434766102274844688",
'   "resultSizeEstimate": 103
' }
' 

' Next, we'll be sending an HTTP POST to add the label "questions" to each message in the
' search results.  The JSON to be sent for the batchModify is this:

' 	{
' 	  "ids": [
' 	    string
' 	  ],
' 	  "addLabelIds": [
' 	    string
' 	  ],
' 	  "removeLabelIds": [
' 	    string
' 	  ]
' 	}

' We'll omit "removeLabelIds" because we're not removing any labels.
' We are parsing the JSON search results, and at the same time building the batchModify JSON.

Dim json2 As New Chilkat.JsonObject

Dim i As Integer = 0
Dim numMessages As Integer = json.SizeOfArray("messages")
While (i < numMessages)
    json.I = i
    Dim id As String = json.StringOf("messages[i].id")
    json2.I = i
    json2.UpdateString("ids[i]",id)
    i = i + 1
End While

' We need the id of the label (not the name).
' I know the name of the label is "questions", but I need to know the id.
' See this example: Get Label Id by Name
' The id of my label named "questions" is "Label_43"
Dim labelId As String = "Label_43"
json2.UpdateString("addLabelIds[0]",labelId)
json2.UpdateNewArray("removeLabelIds")

json2.EmitCompact = False
Debug.WriteLine(json2.Emit())

' Send the batchModify
url = "https://www.googleapis.com/gmail/v1/users/{$userId}/messages/batchModify"
Dim resp As Chilkat.HttpResponse = http.PostJson3(url,"application/json",json2)
If (http.LastMethodSuccess <> True) Then
    Debug.WriteLine(http.LastErrorText)
    Exit Sub
End If


Debug.WriteLine("status = " & resp.StatusCode)

' A 204 response status indicate success.
If (resp.StatusCode <> 204) Then
    Debug.WriteLine(resp.BodyStr)
    Debug.WriteLine("Failed.")

    Exit Sub
End If


' The 204 response has an empty response body..


Debug.WriteLine("BatchModify success!")