From e7948357346de8166166a039794233ce272b29a2 Mon Sep 17 00:00:00 2001
From: Gabriel Jaldon <gjaldon85@gmail.com>
Date: Fri, 16 Sep 2016 21:02:18 +0800
Subject: [PATCH] Join admin:active_users topic on mount of Chat.

The admin:active_users topic is used to track the
presence of users currently connected to our app.
We need to join the topic every time the Chat
component is mounted so the admin can be made
aware that a user is online.
---
 src/PhoenixChat.jsx | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/PhoenixChat.jsx b/src/PhoenixChat.jsx
index f1e46fe..a81ef89 100644
--- a/src/PhoenixChat.jsx
+++ b/src/PhoenixChat.jsx
@@ -116,6 +116,7 @@ export class PhoenixChat extends React.Component {
 
   componentWillUnmount() {
     this.channel.leave()
+    this.adminChannel.leave()
   }
 
   configureChannels(room) {
@@ -135,6 +136,12 @@ export class PhoenixChat extends React.Component {
         messages: this.state.messages.concat([payload])
       })
     })
+
+    this.adminChannel = this.socket.channel(`admin:active_users`)
+    this.adminChannel.join()
+      .receive("ok", ({ id }) => {
+        console.log(`${id} succesfully joined the active_users topic.`)
+      })
   }
 
   handleMessageSubmit(e) {