(PowerBuilder) Microsoft Graph -- Renew Expiring Access Token (Azure AD Endpoint)

Demonstrates how to renew an expiring access token using the refresh token. This example is for renewing an access token using the Azure AD endpoint (not the Azure AD v2.0 endpoint).

An app needs to watch for the expiration of these tokens and renew the expiring access token before the refresh token expires.

This example requires Chilkat v9.5.0.67 or greater.

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

integer li_rc
oleobject loo_Json
integer li_Success
oleobject loo_DtExpire
oleobject loo_Req
oleobject loo_Http
oleobject loo_Resp
oleobject loo_Fac

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

// We previously obtained an access token and saved the JSON to a file using this example:
// Get Access Token using Azure AD Endpoint

// This example will examine the JSON and expiration date, and if near expiration will
// refresh the access token.

loo_Json = create oleobject
// Use "Chilkat_9_5_0.JsonObject" for versions of Chilkat < 10.0.0
li_rc = loo_Json.ConnectToNewObject("Chilkat.JsonObject")
if li_rc < 0 then
    destroy loo_Json
    MessageBox("Error","Connecting to COM object failed")
    return
end if
li_Success = loo_Json.LoadFile("qa_data/tokens/microsoftGraphAzureAD.json")
if li_Success <> 1 then
    destroy loo_Json
    return
end if

// The contents of the JSON look like this:
// {
//     "token_type":"Bearer",
//     "scope": "Calendar.ReadWrite Directory.Read.All Files.ReadWrite Group.ReadWrite.All Mail.ReadWrite Mail.Send User.ReadBasic.All",
//     "expires_in":"3599",
//     "ext_expires_in": "0",
//     "expires_on":"1426551729",
//     "not_before":"1426547829",
//     "resource":"https://graph.microsoft.com/",
//     "access_token":"eyJ0eXAiOiJKV1QiLCJhb...",
//     "refresh_token":"AAABAAAAvPM1KaPlrEqd...",
//     "id_token":"eyJ0eXAiOiJKV1QiLCJhbGci..."
// }

// The "expires_on" value is a Unix time.
loo_DtExpire = create oleobject
// Use "Chilkat_9_5_0.CkDateTime" for versions of Chilkat < 10.0.0
li_rc = loo_DtExpire.ConnectToNewObject("Chilkat.CkDateTime")

loo_DtExpire.SetFromUnixTime(0,loo_Json.IntOf("expires_on"))

// If this date/time expires within 10 minutes of the current system time, refresh the token.
if loo_DtExpire.ExpiresWithin(10,"minutes") <> 1 then
    Write-Debug "No need to refresh, the access token won't expire within the next 10 minutes."
    destroy loo_Json
    destroy loo_DtExpire
    return
end if

// OK, we need to refresh the access token by sending a POST like this:
// 

// 	POST https://login.microsoftonline.com/common/oauth2/token HTTP/1.1
// 	Host: login.microsoftonline.com
// 	Content-Type: application/x-www-form-urlencoded
// 	Content-Length: ***
// 
// 	grant_type=refresh_token
// 	&redirect_uri=http%3A%2F%2Flocalhost%3A3017%2F
// 	&client_id=8b8539cd-7b75-427f-bef1-4a6264fd4940
// 	&client_secret=PJW3dznGfyNSm3rM9aHeXWGKsTMepKXT1Eqy45XXdU4%3D
// 	&refresh_token=AAABAAAAvPM1KaPlrEqdFSBzjqfTGM74--...
// 	&resource=https%3A%2F%2Fgraph.microsoft.com%2F

loo_Req = create oleobject
// Use "Chilkat_9_5_0.HttpRequest" for versions of Chilkat < 10.0.0
li_rc = loo_Req.ConnectToNewObject("Chilkat.HttpRequest")

loo_Req.AddParam("grant_type","refresh_token")
loo_Req.AddParam("redirect_uri","http://localhost:3017/")
loo_Req.AddParam("client_id","MY_AZURE_AD_APP_ID")
loo_Req.AddParam("client_secret","MY_AZURE_AD_APP_KEY")
loo_Req.AddParam("refresh_token",loo_Json.StringOf("refresh_token"))
loo_Req.AddParam("resource","https://graph.microsoft.com/")

loo_Http = create oleobject
// Use "Chilkat_9_5_0.Http" for versions of Chilkat < 10.0.0
li_rc = loo_Http.ConnectToNewObject("Chilkat.Http")

loo_Resp = loo_Http.PostUrlEncoded("https://login.microsoftonline.com/common/oauth2/token",loo_Req)
if loo_Http.LastMethodSuccess <> 1 then
    Write-Debug loo_Http.LastErrorText
    destroy loo_Json
    destroy loo_DtExpire
    destroy loo_Req
    destroy loo_Http
    return
end if

// Load the JSON response.
loo_Json.Load(loo_Resp.BodyStr)
loo_Json.EmitCompact = 0

// Show the JSON response.
Write-Debug loo_Json.Emit()

Write-Debug "Response status code: " + string(loo_Resp.StatusCode)

// If the response status code is not 200, then it's an error.
if loo_Resp.StatusCode <> 200 then
    destroy loo_Json
    destroy loo_DtExpire
    destroy loo_Req
    destroy loo_Http
    return
end if

destroy loo_Resp

// Save the refreshed access token JSON to a file for future requests.
loo_Fac = create oleobject
// Use "Chilkat_9_5_0.FileAccess" for versions of Chilkat < 10.0.0
li_rc = loo_Fac.ConnectToNewObject("Chilkat.FileAccess")

loo_Fac.WriteEntireTextFile("qa_data/tokens/microsoftGraphAzureAD.json",loo_Json.Emit(),"utf-8",0)


destroy loo_Json
destroy loo_DtExpire
destroy loo_Req
destroy loo_Http
destroy loo_Fac