Classic ASP
Microsoft Graph -- List Users (Automatic OAuth2 Client Credentials)

Simplify OAuth2 client credentials by using Chilkat to automatically obtain the necessary access token. This example demonstrates the technique with the Microsoft Graph API's "List Users" request.
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Classic ASP
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<%
success = 0

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

' Instead of directly sending a POST request to obtain an OAuth2 access token, 
' you can provide Chilkat with the necessary information to automatically fetch 
' the token using the Client Credentials flow. During the first HTTP request, 
' Chilkat will obtain the token if it doesn't have one yet, and then use it for 
' all subsequent requests. When the token is expired or about to expire, Chilkat 
' will automatically obtain a new one, eliminating the need for your application 
' to manage token expiration and renewal manually. This approach also reduces the 
' number of HTTP requests by utilizing valid tokens as long as possible.

set json = Server.CreateObject("Chilkat.JsonObject")
success = json.UpdateString("client_secret","CLIENT_SECRET")
success = json.UpdateString("client_id","CLIENT_ID")
success = json.UpdateString("token_endpoint","https://login.microsoftonline.com/TENANT_ID/oauth2/v2.0/token")
success = json.UpdateString("scope","https://graph.microsoft.com/.default")

set http = Server.CreateObject("Chilkat.Http")

' Provide the information to let Chilkat automatically obtain the access token.
http.AuthToken = json.Emit()

set sbResponse = Server.CreateObject("Chilkat.StringBuilder")

success = http.QuickGetSb("https://graph.microsoft.com/v1.0/users",sbResponse)
If (success <> 1) Then
    Response.Write "<pre>" & Server.HTMLEncode( http.LastErrorText) & "</pre>"
    Response.End
End If

success = json.LoadSb(sbResponse)
json.EmitCompact = 0

Response.Write "<pre>" & Server.HTMLEncode( "Status code = " & http.LastStatus) & "</pre>"
If (http.LastStatus <> 200) Then
    Response.Write "<pre>" & Server.HTMLEncode( json.Emit()) & "</pre>"
    Response.Write "<pre>" & Server.HTMLEncode( "Failed.") & "</pre>"
End If

Response.Write "<pre>" & Server.HTMLEncode( json.Emit()) & "</pre>"

' Sample output
' {
'   "@odata.context": "https://graph.microsoft.com/v1.0/$metadata#users",
'   "value": [
'     {
'       "@odata.id": "https://graph.microsoft.com/v2/6d8ddd66-68d1-43b0-af5c-e31b4b7dd5cd/directoryObjects/fca490d8-5918-4201-8079-c5dcbeafcdc9/Microsoft.DirectoryServices.User",
'       "businessPhones": [
'       ],
'       "displayName": "Joe Sample",
'       "givenName": "Joe",
'       "jobTitle": null,
'       "mail": null,
'       "mobilePhone": null,
'       "officeLocation": null,
'       "preferredLanguage": null,
'       "surname": "Sample",
'       "userPrincipalName": "admin_chilkatsoft.com#EXT#@adminchilkatsoft.onmicrosoft.com",
'       "id": "fca490d8-5918-4201-8079-c5dcbeafcdc9"
'     }
'   ]
' }

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

odata_context = json.StringOf("""@odata.context""")
i = 0
count_i = json.SizeOfArray("value")
Do While i < count_i
    json.I = i
    odata_id = json.StringOf("value[i].""@odata.id""")
    displayName = json.StringOf("value[i].displayName")
    givenName = json.StringOf("value[i].givenName")
    jobTitle = json.StringOf("value[i].jobTitle")
    mail = json.StringOf("value[i].mail")
    mobilePhone = json.StringOf("value[i].mobilePhone")
    officeLocation = json.StringOf("value[i].officeLocation")
    preferredLanguage = json.StringOf("value[i].preferredLanguage")
    surname = json.StringOf("value[i].surname")
    userPrincipalName = json.StringOf("value[i].userPrincipalName")
    id = json.StringOf("value[i].id")
    j = 0
    count_j = json.SizeOfArray("value[i].businessPhones")
    Do While j < count_j
        json.J = j
        j = j + 1
    Loop
    i = i + 1
Loop

%>
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