C#

Refresh HMRC OAuth2 Access Token

See more OAuth2 Examples

Demonstrates how to refresh an HMRC access token. C#

bool success = false;

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

//  See Get HMRC Access Token 
//  for sample code showing how to obtain a HMRC access token for desktop apps.

//  It is assumed we previously obtained an OAuth2 access token for HMRC.

Chilkat.JsonObject jsonToken = new Chilkat.JsonObject();
success = jsonToken.LoadFile("qa_data/tokens/hmrc.json");
if (success != true) {
    Debug.WriteLine("Failed to load hmrc.json");
    return;
}

//  The access token JSON looks something 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": "..."
//  }

Chilkat.OAuth2 oauth2 = new Chilkat.OAuth2();

oauth2.TokenEndpoint = "https://test-api.service.hmrc.gov.uk/oauth/token";

//  Replace these with actual values.
oauth2.ClientId = "HMRC-CLIENT-ID";
oauth2.ClientSecret = "HMRC-CLIENT-SECRET";

//  Get the "refresh_token"
oauth2.RefreshToken = jsonToken.StringOf("refresh_token");

//  Send the HTTP POST to refresh the access token..
success = oauth2.RefreshAccessToken();
if (success != true) {
    Debug.WriteLine(oauth2.LastErrorText);
    return;
}

//  Load the access token response into the json object 
jsonToken.Load(oauth2.AccessTokenResponse);

//  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 (jsonToken.HasMember("expires_on") == false) {
    Chilkat.CkDateTime dtExpire = new Chilkat.CkDateTime();
    dtExpire.SetFromCurrentSystemTime();
    dtExpire.AddSeconds(jsonToken.IntOf("expires_in"));
    jsonToken.AppendString("expires_on",dtExpire.GetAsUnixTimeStr(false));
}

//  Save the new JSON access token response to a file.
//  The access + refresh tokens contained in this JSON will be needed for the next refresh.
Chilkat.StringBuilder sbJson = new Chilkat.StringBuilder();
jsonToken.EmitCompact = false;
jsonToken.EmitSb(sbJson);
sbJson.WriteFile("qa_data/tokens/hmrc.json","utf-8",false);

Debug.WriteLine("OAuth2 authorization granted!");
Debug.WriteLine("New Access Token = " + oauth2.AccessToken);