We should now start writing some data to ETS since we have all of the code and support in place to handle that! We'll also want to add a ChatCache.write(...) call in any place that we had any code that dealt with modifying Phoenix Presence data! Open up lib/vocial_web/channels/chat_channel.ex, and we'll start by adding a new alias to the top of our module to make accessing our ChatCache module a little easier:
alias Vocial.ChatCache
Next, our first function in our file that deals with Presence is our handle_in function for dealing with the user_idle status message, so we'll add a single line at the top of the function to handle that:
def handle_in("user_idle", %{"username" => username}, socket) do ChatCache.write(socket.topic, ...
