(DataFlex) 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 ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

Use ChilkatAx-win32.pkg

Procedure Test
    Handle hoJson
    Boolean iSuccess
    Handle hoDtExpire
    Variant vReq
    Handle hoReq
    Handle hoHttp
    Variant vResp
    Handle hoResp
    Handle hoFac
    String sTemp1
    Integer iTemp1
    Boolean bTemp1

    // 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.

    Get Create (RefClass(cComChilkatJsonObject)) To hoJson
    If (Not(IsComObjectCreated(hoJson))) Begin
        Send CreateComObject of hoJson
    End
    Get ComLoadFile Of hoJson "qa_data/tokens/dynamicsCrm.json" To iSuccess
    If (iSuccess <> True) Begin
        Procedure_Return
    End

    // 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.
    Get Create (RefClass(cComCkDateTime)) To hoDtExpire
    If (Not(IsComObjectCreated(hoDtExpire))) Begin
        Send CreateComObject of hoDtExpire
    End
    Get ComIntOf Of hoJson "expires_on" To iTemp1
    Get ComSetFromUnixTime Of hoDtExpire False iTemp1 To iSuccess

    // 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...
    // 

    Get Create (RefClass(cComChilkatHttpRequest)) To hoReq
    If (Not(IsComObjectCreated(hoReq))) Begin
        Send CreateComObject of hoReq
    End
    Send ComAddParam To hoReq "grant_type" "refresh_token"
    Send ComAddParam To hoReq "redirect_uri" "http://localhost:3017/"
    Send ComAddParam To hoReq "client_id" "DYNAMICS-CRM-CLIENT-ID"
    Send ComAddParam To hoReq "client_secret" "DYNAMICS-CRM-SECRET-KEY"
    Get ComStringOf Of hoJson "refresh_token" To sTemp1
    Send ComAddParam To hoReq "refresh_token" sTemp1
    Send ComAddParam To hoReq "resource" "https://mydynamicsdomain.api.crm.dynamics.com"

    Get Create (RefClass(cComChilkatHttp)) To hoHttp
    If (Not(IsComObjectCreated(hoHttp))) Begin
        Send CreateComObject of hoHttp
    End

    Get pvComObject of hoReq to vReq
    Get ComPostUrlEncoded Of hoHttp "https://login.microsoftonline.com/DYNAMICS-ENDPOINT-GUID/oauth2/token" vReq To vResp
    If (IsComObject(vResp)) Begin
        Get Create (RefClass(cComChilkatHttpResponse)) To hoResp
        Set pvComObject Of hoResp To vResp
    End
    Get ComLastMethodSuccess Of hoHttp To bTemp1
    If (bTemp1 <> True) Begin
        Get ComLastErrorText Of hoHttp To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Load the JSON response.
    Get ComBodyStr Of hoResp To sTemp1
    Get ComLoad Of hoJson sTemp1 To iSuccess
    Set ComEmitCompact Of hoJson To False

    // Show the JSON response.
    Get ComEmit Of hoJson To sTemp1
    Showln sTemp1

    Get ComStatusCode Of hoResp To iTemp1
    Showln "Response status code: " iTemp1

    // If the response status code is not 200, then it's an error.
    Get ComStatusCode Of hoResp To iTemp1
    If (iTemp1 <> 200) Begin
        Procedure_Return
    End

    Send Destroy of hoResp

    // 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.
    Get ComHasMember Of hoJson "expires_on" To bTemp1
    If (bTemp1 <> True) Begin
        Get ComSetFromCurrentSystemTime Of hoDtExpire To iSuccess
        Get ComIntOf Of hoJson "expires_in" To iTemp1
        Get ComAddSeconds Of hoDtExpire iTemp1 To iSuccess
        Get ComGetAsUnixTimeStr Of hoDtExpire False To sTemp1
        Get ComAppendString Of hoJson "expires_on" sTemp1 To iSuccess
    End

    // Save the refreshed access token JSON to a file for future requests.
    Get Create (RefClass(cComCkFileAccess)) To hoFac
    If (Not(IsComObjectCreated(hoFac))) Begin
        Send CreateComObject of hoFac
    End
    Get ComEmit Of hoJson To sTemp1
    Get ComWriteEntireTextFile Of hoFac "qa_data/tokens/dynamicsCrm.json" sTemp1 "utf-8" False To iSuccess


End_Procedure