title: AFNetworking 2.0 with OAuth2 tokens
body: <p>I am trying to find a way to use <code>OAuth2</code> (access and refresh tokens) with <code>AFNetworking</code>. I'm having a hard time finding good documentation bout it.</p>
  
  <p>I know about the <code>AFOAuth2Client</code> project, but that only works for <code>AFNetworking</code> <code>1.x</code>. Are there any good solutions for <code>AFNetworking</code> <code>2.0</code>? </p>
  
  <p>Also, how exactly will the tokens be refreshed? Am I supposed to always check for token expiry for every request? Where exactly can this be done? Or maybe use a timer for when the token expires, then fetch a new one? </p>