(Lianja) Refresh a Dynamics CRM OAuth2 Access Token

Demonstrates how to refresh an expiring Dynamics CRM access token using the refresh token. endpoint.

(If a REST API call fails with a 401 unauthorized error, an application can auto-recover by refreshing the access token, and then re-send the request using the new token.)

Chilkat Lianja Extension Download Chilkat Lianja Extension

//  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 Dynamics CRM OAuth2 Access Token

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

loJson = createobject("CkJsonObject")
llSuccess = loJson.LoadFile("qa_data/tokens/dynamicsCrm.json")
if (llSuccess <> .T.) then
    release loJson
    return
endif

//  The contents of the JSON look like this:
//  {
//    "token_type": "Bearer",
//    "scope": "user_impersonation",
//    "expires_in": "3599",
//    "ext_expires_in": "0",
//    "expires_on": "1524783438",
//    "not_before": "1524779538",
//    "resource": "https://mydomain.api.crm.dynamics.com",
//    "access_token": "...",
//    "refresh_token": "...",
//    "id_token": "..."
//  }

//  The "expires_on" value is a Unix time.
loDtExpire = createobject("CkDateTime")
loDtExpire.SetFromUnixTime(.F.,loJson.IntOf("expires_on"))

//  If this date/time expires within 10 minutes of the current system time, refresh the token.

//  OK, we need to refresh the access token by sending a POST...
// 

loReq = createobject("CkHttpRequest")
loReq.AddParam("grant_type","refresh_token")
loReq.AddParam("redirect_uri","http://localhost:3017/")
loReq.AddParam("client_id","DYNAMICS-CRM-CLIENT-ID")
loReq.AddParam("client_secret","DYNAMICS-CRM-SECRET-KEY")
loReq.AddParam("refresh_token",loJson.StringOf("refresh_token"))
loReq.AddParam("resource","https://mydynamicsdomain.api.crm.dynamics.com")

loHttp = createobject("CkHttp")

loResp = loHttp.PostUrlEncoded("https://login.microsoftonline.com/DYNAMICS-ENDPOINT-GUID/oauth2/token",loReq)
if (loHttp.LastMethodSuccess <> .T.) then
    ? loHttp.LastErrorText
    release loJson
    release loDtExpire
    release loReq
    release loHttp
    return
endif

//  Load the JSON response.
loJson.Load(loResp.BodyStr)
loJson.EmitCompact = .F.

//  Show the JSON response.
? loJson.Emit()

? "Response status code: " + str(loResp.StatusCode)

//  If the response status code is not 200, then it's an error.
if (loResp.StatusCode <> 200) then
    release loJson
    release loDtExpire
    release loReq
    release loHttp
    return
endif

release loResp

//  If an "expires_on" member does not exist, then add the JSON member by
//  getting the current system date/time and adding the "expires_in" seconds.
//  This way we'll know when the token expires.
if (loJson.HasMember("expires_on") <> .T.) then
    loDtExpire.SetFromCurrentSystemTime()
    loDtExpire.AddSeconds(loJson.IntOf("expires_in"))
    loJson.AppendString("expires_on",loDtExpire.GetAsUnixTimeStr(.F.))
endif

//  Save the refreshed access token JSON to a file for future requests.
loFac = createobject("CkFileAccess")
loFac.WriteEntireTextFile("qa_data/tokens/dynamicsCrm.json",loJson.Emit(),"utf-8",.F.)


release loJson
release loDtExpire
release loReq
release loHttp
release loFac