So far, our chat application has made use of the OAuth2 protocol to allow users to sign in to our application so that we know who is saying what. In this chapter, we are going to add profile pictures to make the chatting experience more engaging.
We will look at the following ways to add pictures or avatars alongside the messages in our application:
Using the avatar picture provided by the authentication server
Using the Gravatar.com web service to look up a picture by the user's e-mail address
Allowing the user to upload their own picture and host it themselves
The first two options allow us to delegate the hosting of pictures to a third party—either an authentication service or Gravatar.com—which is great because it reduces the cost of hosting our application (in terms of storage costs and bandwidth, since the user's browsers will actually download the pictures from the servers of the authenticating service, not ours). The third option requires...