Xbase++

Refresh a Dynamics CRM OAuth2 Access Token

See more OAuth2 Examples

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.)

Xbase++

LOCAL nSuccess
LOCAL oJson
LOCAL oDtExpire
LOCAL oReq
LOCAL oHttp
LOCAL oResp
LOCAL oFac

nSuccess := 0

//  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.

oJson := CreateObject("Chilkat.JsonObject")
nSuccess := oJson:LoadFile("qa_data/tokens/dynamicsCrm.json")
IF (nSuccess != 1)
    oJson:destroy()
    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.
oDtExpire := CreateObject("Chilkat.CkDateTime")
oDtExpire:SetFromUnixTime(0, oJson: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...
//  

oReq := CreateObject("Chilkat.HttpRequest")
oReq:AddParam("grant_type", "refresh_token")
oReq:AddParam("redirect_uri", "http://localhost:3017/")
oReq:AddParam("client_id", "DYNAMICS-CRM-CLIENT-ID")
oReq:AddParam("client_secret", "DYNAMICS-CRM-SECRET-KEY")
oReq:AddParam("refresh_token", oJson:StringOf("refresh_token"))
oReq:AddParam("resource", "https://mydynamicsdomain.api.crm.dynamics.com")

oHttp := CreateObject("Chilkat.Http")

oReq:HttpVerb := "POST"
oReq:ContentType := "application/x-www-form-urlencoded"

oResp := CreateObject("Chilkat.HttpResponse")
nSuccess := oHttp:HttpReq("https://login.microsoftonline.com/DYNAMICS-ENDPOINT-GUID/oauth2/token", oReq, oResp)
IF (nSuccess == 0)
    ? oHttp:LastErrorText
    oJson:destroy()
    oDtExpire:destroy()
    oReq:destroy()
    oHttp:destroy()
    oResp:destroy()
    RETURN
ENDIF

//  Load the JSON response.
oJson:Load(oResp:BodyStr)
oJson:EmitCompact := 0

//  Show the JSON response.
? oJson:Emit()

? "Response status code: " + Str(oResp:StatusCode)

//  If the response status code is not 200, then it's an error.
IF (oResp:StatusCode != 200)
    oJson:destroy()
    oDtExpire:destroy()
    oReq:destroy()
    oHttp:destroy()
    oResp:destroy()
    RETURN
ENDIF

//  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 (oJson:HasMember("expires_on") != 1)
    oDtExpire:SetFromCurrentSystemTime()
    oDtExpire:AddSeconds(oJson:IntOf("expires_in"))
    oJson:AppendString("expires_on", oDtExpire:GetAsUnixTimeStr(0))
ENDIF

//  Save the refreshed access token JSON to a file for future requests.
oFac := CreateObject("Chilkat.FileAccess")
oFac:WriteEntireTextFile("qa_data/tokens/dynamicsCrm.json", oJson:Emit(), "utf-8", 0)

oJson:destroy()
oDtExpire:destroy()
oReq:destroy()
oHttp:destroy()
oResp:destroy()
oFac:destroy()