I have a client application that use the oauth2 with authorization grant type resource owner password credential. I write a curl http request to obtain the access token when user provide her credential, but how to request another access token when the first one expired. I read that it's good to estimate the validity of the access token. I found this client library but I don't think it will solve my problem related to requesting a new access token once it expire or even when the refresh token expired too.
Can anyone point me to the right direction how to implement this or use a library for that purpose please?