title: User authentication and Session handling in iOS with swift
body: <p>I am fairly new to Swift and I am required to develop an app which <code>authenticates</code> username and password through a <code>REST API</code> in <code>Azure</code>. I have successfully called the API and received the <code>JSON</code> string for a valid user.
  Now I want to make the user login to the app with his credentials after authentication, a session should be created so that user data persists after login and till he doesn't log out. </p>
  
  <p>I am confused on how to create the session of the user. Can I get any resource where I can find how it is done?</p>
  
  <p>PS: I don't want to use <code>Parse</code> or any other framework. I already have created custom API in azure which I call for retrieving data as <code>JSON String.</code></p>