Merge pull request #3 from elixirschool/mts/add_presence

Add Phoenix Presence

Author: michaelstalker

assets/js/app.js

@@ -14,4 +14,4 @@ import "phoenix_html"
 // Import local files
 //
 // Local files can be imported directly using relative paths, for example:
-// import socket from "./socket"
+import socket from "./socket"

assets/js/socket.js

@@ -1,63 +1,25 @@
-// NOTE: The contents of this file will only be executed if
-// you uncomment its entry in "assets/js/app.js".
+import {Socket, Presence} from 'phoenix'
 
-// To use Phoenix channels, the first step is to import Socket,
-// and connect at the socket path in "lib/web/endpoint.ex".
-//
-// Pass the token on params as below. Or remove it
-// from the params if you are not using authentication.
-import {Socket} from "phoenix"
+const socket = new Socket('/socket', {params: {username: window.pointingParty.username}})
+socket.connect()
 
-let socket = new Socket("/socket", {params: {token: window.userToken}})
+const channel = socket.channel('room:lobby', {})
+const presence = new Presence(channel)
 
-// When you connect, you'll often need to authenticate the client.
-// For example, imagine you have an authentication plug, `MyAuth`,
-// which authenticates the session and assigns a `:current_user`.
-// If the current user exists you can assign the user's token in
-// the connection for use in the layout.
-//
-// In your "lib/web/router.ex":
-//
-//     pipeline :browser do
-//       ...
-//       plug MyAuth
-//       plug :put_user_token
-//     end
-//
-//     defp put_user_token(conn, _) do
-//       if current_user = conn.assigns[:current_user] do
-//         token = Phoenix.Token.sign(conn, "user socket", current_user.id)
-//         assign(conn, :user_token, token)
-//       else
-//         conn
-//       end
-//     end
-//
-// Now you need to pass this token to JavaScript. You can do so
-// inside a script tag in "lib/web/templates/layout/app.html.eex":
-//
-//     <script>window.userToken = "<%= assigns[:user_token] %>";</script>
-//
-// You will need to verify the user token in the "connect/3" function
-// in "lib/web/channels/user_socket.ex":
-//
-//     def connect(%{"token" => token}, socket, _connect_info) do
-//       # max_age: 1209600 is equivalent to two weeks in seconds
-//       case Phoenix.Token.verify(socket, "user socket", token, max_age: 1209600) do
-//         {:ok, user_id} ->
-//           {:ok, assign(socket, :user, user_id)}
-//         {:error, reason} ->
-//           :error
-//       end
-//     end
-//
-// Finally, connect to the socket:
-socket.connect()
+presence.onSync(() => {
+  const users = document.querySelector('.users')
+  users.innerHTML = ''
+
+  presence.list((id, _) => {
+    const user = document.createElement('li')
+    user.setAttribute('class', id)
+    user.appendChild(document.createTextNode(id))
+    users.appendChild(user)
+  })
+})
 
-// Now that you are connected, you can join channels with a topic:
-let channel = socket.channel("topic:subtopic", {})
 channel.join()
-  .receive("ok", resp => { console.log("Joined successfully", resp) })
-  .receive("error", resp => { console.log("Unable to join", resp) })
+  .receive('ok', resp => { console.log('Joined successfully', resp) })
+  .receive('error', resp => { console.log('Unable to join', resp) })
 
 export default socket