ChannelList
The ChannelList
component queries an array of channel
objects from the Stream Chat API and displays as a customizable list
in the UI. It accepts props for filters
, sort
and options
, which allows you to tailor
your request to the Query Channels API. The
response array from this API is then rendered in a list and loaded into the DOM.
const channels = await client.queryChannels(filters, sort, options);
The ChannelList
component also comes pre-built with navigation functionality. The click of a list item sets the active
channel
object and loads the Channel
component.
Basic Usage
The ChannelList
does not have any required props, but in order to refine channel query results we recommend providing
values for filters
, sort
and options
.
By default when channels query does not have any filter it will match all the channels in your application. While this might be convenient during the development, you most likely want to have at least some basic filtering.
At a minimum, the filter should include {members: { $in: [userID] }}
.
const filters = { members: { $in: [ 'jimmy', 'buffet' ] } }
const sort = { last_message_at: -1 };
const options = { limit: 10 }
<Chat client={client}>
<ChannelList filters={filters} sort={sort} options={options} />
<Channel>
<MessageList />
<MessageInput />
</Channel>
</Chat>
UI Customization
ChannelList
UI is determined by two of its props, List
and Preview
. The List
prop allows you to customize the container
in which the array of channels is rendered. The Preview
prop dictates the design and click functionality of an individual
channel in the list. If not provided via props, these UI components default to
ChannelListMessenger
and ChannelPreviewMessenger
.
To customize the container and list item UI for your ChannelList
, provide custom component overrides. Your custom components
will receive the same props as the defaults.
const CustomListContainer = (props) => {
// render custom list container here
};
const CustomListItem = (props) => {
// render custom list item here
};
<Chat client={client}>
<ChannelList List={CustomListContainer} Preview={CustomListItem} />
<Channel>
<MessageList />
<MessageInput />
</Channel>
</Chat>;
In cases where the customizations provided by Preview
are not enough, e.g. grouping channels under sections based on some
dynamic channel data, the renderChannels
may be a good fit as all loaded channels are passed as an argument to the function.
const renderChannels = (loadedChannels, ChannelPreview) => {
const groups = groupBy(loadedChannels, 'some_custom_channel_data');
return renderGroups(groups); // inside renderGroups you have have headings, etc...
}
<Chat client={client}>
<ChannelList {/* other props */} renderChannels={renderChannels} />
<Channel>
<MessageList />
<MessageInput />
</Channel>
</Chat>;
Event Listeners
In order to handle the requisite, dynamic nature of the ChannelList
, a variety of
event listeners are added on component mount.
Many of these event listeners accept custom handler functions, allowing you to override the library's default event response behavior.
Each custom handler accepts the same function arguments. Through a combination of pulling updated data off the event object and re-setting the list state, you can customize behavior and UI.
setChannels
- state setter for thechannels
value which populates the list in the DOMevent
- event object returned from each corresponding event listener
Event Type | Default Behavior | Custom Handler |
---|---|---|
channel.deleted | Removes channel from list | onChannelDeleted |
channel.hidden | Removes channel from list | onChannelHidden |
channel.truncated | Updates the channel | onChannelTruncated |
channel.updated | Updates the channel | onChannelUpdated |
channel.visible | Adds channel to list | onChannelVisible |
connection.recovered | Forces a component render | N/A |
message.new | Moves channel to top of list | onMessageNewHandler |
notification.added_to_channel | Moves channel to top of list and starts watching | onAddedToChannel |
notification.message_new | Moves channel to top of list and starts watching | onMessageNew |
notification.removed_from_channel | Removes channel from list | onRemovedFromChannel |
user.presence.changed | Updates the channel | N/A |
Customizing Event Handlers
The event type the ChannelList
reacts to and its corresponding behavior can be overridden using the appropriate prop. Let's look at an example of customizing the ChannelList component to only display frozen channels.
const filters = {
members: { $in: ['dan'] },
frozen: true
}
<ChannelList filters={filters} />
The notification.message_new
event occurs when a message is received on a channel that is not loaded but the current user is a member of.
The default behavior when this event occurs is to query the channel the message is received on, then add the channel to the top of the list, irrespective of filters
.
Thus, if a new message appears in an unfrozen channel of which the current user is a member, it will be added to the list. This may not be the desired behavior since the list is only supposed to show frozen channels.
In this case, you can replace the default functionality by providing a custom onMessageNew
function as a prop to the ChannelList
component.
onMessageNew
receives two parameters when called, setChannels
, a setter function for the internal channels
state, and event
, the Event
object received for the notification.message_new
event.
These parameters can be used to create a function that achieves the desired custom behavior.
const filters = {
members: { $in: ['dan'] },
frozen: true,
};
const customOnMessageNew = async (setChannels, event) => {
const eventChannel = event.channel;
// If the channel isn't frozen, then don't add it to the list.
if (!eventChannel?.id || !eventChannel.frozen) return;
try {
const newChannel = client.channel(eventChannel.type, eventChannel.id);
await newChannel.watch();
setChannels((channels) => [newChannel, ...channels]);
} catch (error) {
console.log(error);
}
};
<ChannelList filters={filters} onMessageNew={customOnMessageNew} />;
Similarly, events other than notification.message_new
can be handled as per application requirements.
Props
additionalChannelSearchProps
Additional props to be passed to the underlying ChannelSearch
component.
Type |
---|
object |
allowNewMessagesFromUnfilteredChannels
When the client receives message.new
, notification.message_new
, and notification.added_to_channel
events, we automatically push
that channel to the top of the list. If the channel doesn't currently exist in the list, we grab the channel from client.activeChannels
and push it to the top of the list. You can disable this behavior by setting this prop to false, which will prevent channels not in the
list from incrementing the list.
Type | Default |
---|---|
boolean | true |
Avatar
Custom UI component to display the user's avatar.
Type | Default |
---|---|
component | Avatar |
channelRenderFilterFn
Optional function to filter channels prior to loading in the DOM. Do not use any complex or async logic that would delay the
loading of the ChannelList
. We recommend using a pure function with array methods like filter/sort/reduce.
Type |
---|
(channels: Channel[]) => Channel[] |
ChannelSearch
Custom UI component to display search results.
Type | Default |
---|---|
component | ChannelSearch |
customActiveChannel
Set a channel (with this ID) to active and force it to move to the top of the list.
Type |
---|
string |
customQueryChannels
Custom function that handles the channel pagination.
Takes parameters:
Parameter | Description |
---|---|
currentChannels | The state of loaded Channel objects queried thus far. Has to be set with setChannels (see below). |
queryType | A string indicating, whether the channels state has to be reset to the first page ('reload') or newly queried channels should be appended to the currentChannels . |
setChannels | Function that allows us to set the channels state reflected in currentChannels . |
setHasNextPage | Flag indicating whether there are more items to be loaded from the API. Should be infered from the comparison of the query result length and the query options limit. |
The function has to:
- build / provide own query filters, sort and options parameters
- query and append channels to the current channels state
- update the
hasNext
pagination flag after each query withsetChannels
function
An example below implements a custom query function that uses different filters sequentially once a preceding filter is exhausted:
import uniqBy from "lodash.uniqby";
import throttle from 'lodash.throttle';
import {useCallback, useRef} from 'react';
import {ChannelFilters, ChannelOptions, ChannelSort, StreamChat} from 'stream-chat';
import {
CustomQueryChannelParams,
useChatContext,
} from 'stream-chat-react';
const DEFAULT_PAGE_SIZE = 30 as const;
export const useCustomQueryChannels = () => {
const { client } = useChatContext();
const filters1: ChannelFilters = {
member_count: { $gt: 10 },
members: { $in: [client.user?.id || ''] },
type: 'messaging',
};
const filters2: ChannelFilters = { members: { $in: [client.user?.id || ''] }, type: 'messaging' };
const options: ChannelOptions = { limit: 10, presence: true, state: true };
const sort: ChannelSort = { last_message_at: -1, updated_at: -1 };
const filtersArray = [filters1, filters2];
const appliedFilterIndex = useRef(0);
const customQueryChannels = useCallback(
throttle(
async ({
currentChannels,
queryType,
setChannels,
setHasNextPage,
}: CustomQueryChannelParams) => {
const offset = queryType === 'reload' ? 0 : currentChannels.length;
const newOptions = {
limit: options.limit ?? DEFAULT_PAGE_SIZE,
offset,
...options,
};
const filters = filtersArray[appliedFilterIndex.current];
const channelQueryResponse = await client.queryChannels(filters, sort || {}, newOptions);
const newChannels =
queryType === 'reload'
? channelQueryResponse
: uniqBy([...currentChannels, ...channelQueryResponse], 'cid');
setChannels(newChannels);
const lastPageForCurrentFilter = channelQueryResponse.length < newOptions.limit;
const isLastPageForAllFilters =
lastPageForCurrentFilter && appliedFilterIndex.current === filtersArray.length - 1;
setHasNextPage(!isLastPageForAllFilters);
if (lastPageForCurrentFilter) {
appliedFilterIndex.current += 1;
}
},
500,
{ leading: true, trailing: false },
),
[client, filtersArray],
);
return customQueryChannels;
};
It is recommended to control for duplicate requests by throttling the custom function calls.
Type |
---|
CustomQueryChannelsFn |
EmptyStateIndicator
Custom UI component for rendering an empty list.
Type | Default |
---|---|
component | EmptyStateIndicator |
filters
An object containing channel query filters, check our query parameters docs for more information.
Type |
---|
object |
List
Custom UI component to display the container for the queried channels.
Type | Default |
---|---|
component | ChannelListMessenger |
LoadingErrorIndicator
Custom UI component to display the loading error indicator.
Type | Default |
---|---|
component | ChatDown |
LoadingIndicator
Custom UI component to display the loading state.
Type | Default |
---|---|
component | LoadingChannels |
lockChannelOrder
When true, channels won't dynamically sort by most recent message.
Type | Default |
---|---|
boolean | false |
onAddedToChannel
Function to override the default behavior when a user is added to a channel.
Type |
---|
function |
onChannelDeleted
Function to override the default behavior when a channel is deleted.
Type |
---|
function |
onChannelHidden
Function to override the default behavior when a channel is hidden.
Type |
---|
function |
onChannelTruncated
Function to override the default behavior when a channel is truncated.
Type |
---|
function |
onChannelUpdated
Function to override the default behavior when a channel is updated.
Type |
---|
function |
onChannelVisible
Function to override the default channel visible behavior.
Type |
---|
function |
onMessageNew
Function to override the default behavior when a message is received on a channel not being watched.
Type |
---|
function |
onMessageNewHandler
Function to override the default behavior when a message is received on a channel being watched. Handles message.new
event.
Type |
---|
(setChannels: React.Dispatch<React.SetStateAction<Array<Channel<StreamChatGenerics>>>>, event: Event<StreamChatGenerics>) => void |
onRemovedFromChannel
Function to override the default behavior when a user gets removed from a channel.
Type |
---|
function |
options
An object containing channel query options, check our query parameters docs for more information.
Type |
---|
object |
Paginator
Custom UI component to handle channel pagination logic.
Type | Default |
---|---|
component | LoadMorePaginator |
Preview
Custom UI component to display the channel preview in the list.
Type | Default |
---|---|
component | ChannelPreviewMessenger |
recoveryThrottleIntervalMs
Custom interval during which the recovery channel list queries will be prevented. This is to avoid firing unnecessary queries during internet connection fluctuation. Recovery channel query is triggered upon internet connection recovery and leads to complete channel list reload with pagination offset 0. The minimum throttle interval is 2000ms. The default throttle interval is 5000ms.
The channel list recovery mechanism described here (applying recoveryThrottleIntervalMs
) is activated only if the StreamChat
client's channel list recovery mechanism is disabled. The StreamChat
recovery mechanism can be disabled when initiating the client instance through the options
parameter:
import { StreamChat } from 'stream-chat';
import { ChannelList, Chat } from 'stream-chat-react';
// ... get apiKey, filters, sort, options
const client = new StreamChat(apiKey, {recoverStateOnReconnect: false});
const App = () => (
<Chat client={client} >
{/** ... */}
<ChannelList
filters={filters}
sort={sort}
options={options}
recoveryThrottleIntervalMs={3000}
{/** other props... */}
/>
{/** ... */}
</Chat>
);
Type | Default |
---|---|
number | 5000 |
renderChannels
Function to override the default behavior when rendering channels, so this function is called instead of rendering the Preview directly.
Type |
---|
function |
sendChannelsToList
If true, sends the list's currently loaded channels to the List
component as the loadedChannels
prop.
Type | Default |
---|---|
boolean | false |
setActiveChannelOnMount
If true, sets the most recent channel received from the query as active on component mount. If set to false
no channel is set as active on mount.
Type | Default |
---|---|
boolean | true |
showChannelSearch
If true, renders the ChannelSearch
component above the List
component.
Type | Default |
---|---|
boolean | false |
sort
An object containing channel query sort parameters. Check our query parameters docs for more information.
Type |
---|
object |
watchers
An object containing query parameters for fetching channel watchers.
Type |
---|
{ limit?: number; offset?: number } |