|
| 1 | +--- |
| 2 | +id: channel-user-lists |
| 3 | +sidebar_position: 21 |
| 4 | +title: Channel Members and Online Status |
| 5 | +--- |
| 6 | + |
| 7 | +In this example, we will demonstrate how to render the current channel members and their online status. |
| 8 | + |
| 9 | +## Render the Channel Members List |
| 10 | + |
| 11 | +Let's start the example by creating a simple members list component. To access the members list of the current channel, we will get the current channel using `useChannelStateContext` hook. |
| 12 | +The example is a bit more convoluted, since we will add online presence updates at the next step. |
| 13 | + |
| 14 | +:::note |
| 15 | +In order for the client to receive updates for user presence, ensure that you are watching the channel with `channel.watch({ presence: true })`. More details can be found in the [↗ LLC documentation](https://getstream.io/chat/docs/javascript/watch_channel/?language=javascript). |
| 16 | +::: |
| 17 | + |
| 18 | +```tsx |
| 19 | +const Users = () => { |
| 20 | + const { channel } = useChannelStateContext(); |
| 21 | + const [channelUsers, setChannelUsers] = useState< |
| 22 | + Array<{ name: string; online: boolean }> |
| 23 | + >([]); |
| 24 | + |
| 25 | + useEffect(() => { |
| 26 | + const updateChannelUsers = () => { |
| 27 | + setChannelUsers( |
| 28 | + Object.values(channel.state.members).map((user) => ({ |
| 29 | + name: user.user_id!, |
| 30 | + online: !!user.user!.online, |
| 31 | + })) |
| 32 | + ); |
| 33 | + }; |
| 34 | + |
| 35 | + updateChannelUsers(); |
| 36 | + }, [client, channel]); |
| 37 | + |
| 38 | + return ( |
| 39 | + <ul className="users-list"> |
| 40 | + {channelUsers.map((member) => ( |
| 41 | + <li key={member.name}> |
| 42 | + {member.name} - {member.online ? "online" : "offline"} |
| 43 | + </li> |
| 44 | + ))} |
| 45 | + </ul> |
| 46 | + ); |
| 47 | +}; |
| 48 | +``` |
| 49 | + |
| 50 | +We can put the component as a child of the `Channel` component: |
| 51 | + |
| 52 | +```tsx |
| 53 | + <Channel> |
| 54 | + <Window> |
| 55 | + <Users /> |
| 56 | + <ChannelHeader /> |
| 57 | + <MessageList /> |
| 58 | + <MessageInput focus /> |
| 59 | + </Window> |
| 60 | + <Thread /> |
| 61 | + </Channel> |
| 62 | +``` |
| 63 | + |
| 64 | +## Real-Time Updates |
| 65 | + |
| 66 | +So far, our list looks good, but there's a catch: for performance purposes, the `useChannelStateContext` does not refresh when user presence changes. |
| 67 | +To make the list refresh accordingly, we need to attach an additional listener to the `user.presence.changed` event of the chat client. |
| 68 | +Let's also add some basic CSS to complete the look of the list. A class is already applied to the JSX, just add a CSS file and be sure to import into your file. |
| 69 | + |
| 70 | +```css |
| 71 | +.users-list { |
| 72 | + background: #ffffff; |
| 73 | + padding: 20px; |
| 74 | + padding-left: 30px; |
| 75 | + border-radius: calc(16px / 2) 16px 0 0; |
| 76 | + border: 1px solid #ecebeb; |
| 77 | +} |
| 78 | +``` |
| 79 | + |
| 80 | +```tsx |
| 81 | +const Users = () => { |
| 82 | + const { client } = useChatContext(); |
| 83 | + const { channel } = useChannelStateContext(); |
| 84 | + const [channelUsers, setChannelUsers] = useState< |
| 85 | + Array<{ name: string; online: boolean }> |
| 86 | + >([]); |
| 87 | + useEffect(() => { |
| 88 | + const updateChannelUsers = (event?: Event) => { |
| 89 | + // test if the updated user is a member of this channel |
| 90 | + if (!event || channel.state.members[event.user!.id] !== undefined) { |
| 91 | + setChannelUsers( |
| 92 | + Object.values(channel.state.members).map((user) => ({ |
| 93 | + name: user.user_id!, |
| 94 | + online: !!user.user!.online, |
| 95 | + })) |
| 96 | + ); |
| 97 | + } |
| 98 | + }; |
| 99 | + |
| 100 | + updateChannelUsers(); |
| 101 | + |
| 102 | + // |
| 103 | + client.on("user.presence.changed", updateChannelUsers); |
| 104 | + |
| 105 | + return () => { |
| 106 | + client.off("user.presence.changed", updateChannelUsers); |
| 107 | + }; |
| 108 | + }, [client, channel]); |
| 109 | + |
| 110 | + return ( |
| 111 | + <ul className="users-list"> |
| 112 | + {channelUsers.map((member) => ( |
| 113 | + <li key={member.name}> |
| 114 | + {member.name} - {member.online ? "online" : "offline"} |
| 115 | + </li> |
| 116 | + ))} |
| 117 | + </ul> |
| 118 | + ); |
| 119 | +}; |
| 120 | +``` |
| 121 | + |
| 122 | +With the above addition, `channelUsers` will be updated each time user comes online or goes offline. |
| 123 | + |
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