Check if Xero OAuth 2.0 Access Token has Expired

Question

I know this may sound simple to those of you who are well versed in OAuth 2.0, but I am still trying to understand it all. I am having to migrate my Xero OAuth 1.0 app to Xero OAuth 2.0. I am able to connect and get back a token. I am saving the refresh token in the database. My problem is I do not know when to use it. I have been trying to figure out how to test if the current access_token is expired so that I can refresh if needed, but I can't figure out how to test if the access_token has expired. I am getting and storing the token as follows:

var token = await xeroClient.RequestXeroTokenAsync(oauth_token);

            xeroToken = new XeroOAuth2Token
            {
                AccessToken = token.AccessToken,
                RefreshToken = token.RefreshToken,
                ExpiresAtUtc = token.ExpiresAtUtc

            };

Is there a way to test if the AccessToken has expired so that I know to call the RefreshTokenAsync method?

Answer 1

When you store the token in your data store, store it with the ExpiresAtUtc DateTime property. Then its just as simple as checking whether the current DateTime.UtcNow > token.ExpiresAtUtc.