How to call Microsoft Graph API using VBA? - vba

Question

Question
Is it possible to call Microsoft Graph API using VBA code?
If yes, how to handle O365 authorization? I have seen plenty of topics saying to create an application in Microsoft Azure to get a token but I am surprised I must do that for a simple local use.
What I tried
After discovering Microsoft Graph, I tried this API in Graph Explorer
https://graph.microsoft.com/v1.0/planner/tasks
I was able to create a task in planner!
Consequently, in my mind, it was possible to call this API from VBA code executed directly in Outlook.
I created this macro in Outlook:
Sub TaskPlannerCreation()
Dim PlannerService As New MSXML2.XMLHTTP60
Dim sData As Variant
sData = " { "" ""planId"": ""K9Zv2QHm1U-GSAhd-PTGZfdFeOn"",""bucketId"": ""b6NVNiEIQkGZeBBzn7kWqJvAGvvs"",""title"": ""Outlook task"" } "
With PlannerService
.Open "POST", "https://graph.microsoft.com/v1.0/planner/tasks", False
.setRequestHeader "Content-Type", "application/json"
.setRequestHeader "Accept", "application/json"
.setRequestHeader "User-Agent", "xx"
.Send (sData)
I have an Authorization error with
error code 401
UPDATE on 12-03-2020 :
Solution found to get a Graph Api token analysing URL when calling Graph Explorer (works perfectly for me) :
Function GetToken()
Dim xml As New MSXML2.XMLHTTP60
Dim doc As MSHTML.HTMLDocument
Dim urltoken As String
'copy paste the URL you see when calling Microsoft Graph Explorer and add prompt + domain_hint parameters
urltoken = "https://login.microsoftonline.com/common/oauth2/v2.0/authorize?response_mode=form_post&nonce=graph_explorer&mkt=fr-FR&client_id={clientid}&response_type=token&scope=openid profile User.ReadWrite User.ReadBasic.All Sites.ReadWrite.All Contacts.ReadWrite People.Read Notes.ReadWrite.All Tasks.ReadWrite Mail.ReadWrite Files.ReadWrite.All Calendars.ReadWrite&prompt=none&domain_hint=organizations"
xml.Open "GET", urltoken, False
xml.Send
If xml.readyState = 4 And xml.Status = 200 Then
Set doc = New MSHTML.HTMLDocument
doc.Body.innerHTML = xml.responseText
GetToken = doc.getElementsByName("access_token")(0).Value
sSuccess = True
Else
MsgBox "Error" & vbNewLine & "Ready state: " & xml.readyState & _
vbNewLine & "HTTP request status: " & xml.Status
sSuccess = False
End If
Set xml = Nothing
End Function
So using VBA for calling Graph API is possible :)

Answer 1

So the code you show is only partially correct. Here is what I found to actually work. (This is with what you provided as I actually found a Json parser to work with the data better than the innerHTML methods, I also had to use a different version of MSXML since the one you reference wasnt working for me.)
Function GetToken()
Dim xml As New MSXML2.XMLHTTP60
Dim doc As MSHTML.HTMLDocument
Dim urltoken As String
'copy paste the URL you see when calling Microsoft Graph Explorer and add prompt + domain_hint parameters
urltoken = "https://login.microsoftonline.com/{tenent id}/oauth2/v2.0/token"
xml.Open "POST", urltoken, False
xml.Send("client_id={clientid}&scope=https://graph.microsoft.com/.default&grant_type=client_credentials&client_secret=(cleint secret}")
If xml.readyState = 4 And xml.Status = 200 Then
Set doc = New MSHTML.HTMLDocument
doc.Body.innerHTML = xml.responseText
GetToken = doc.getElementsByName("access_token")(0).Value
sSuccess = True
Else
MsgBox "Error" & vbNewLine & "Ready state: " & xml.readyState & _
vbNewLine & "HTTP request status: " & xml.Status
sSuccess = False
End If
Set xml = Nothing
End Function