Group channel collection
groupChannelCollection retrieves group channels from both the local cache and Sendbird server and lets you quickly create a channel list view without missing any channel-related updates. This page explains how to make a channel list view using the collection and serves as a migration guide.
Create a collection
groupChannelCollectionis the local caching equivalent of SyncManager’s
groupChannelCollection instance can be created through the
createChannelCollection() method. When creating the instance, you can also determine how to filter and order the group channel list.
GroupChannelListQuery instance through the
createMyGroupChannelListQuery() method and query setters. This will determine the number of channels to retrieve for the channel list.
In local caching, the
groupChannelCollectionHandler is used to determine how the client app reacts to channel-related events.
The following table shows when to call each event handler.
- Called when a new group channel is created as a real-time event.
- Called when the channel information that is included in the user's current chat view is updated as a real-time event.
- Called when a group channel is deleted as a real-time event.
handler.onChannelEvent, which is used to handle real-time events, should be changed as shown in the code below.
fetch() method retrieves channels from the local cache and delivers them to the
ChannelCollectionHandler instance. In local caching, the
groupChannelCollection can retrieve channels through two new interfaces,
By default, cached channels are listed in reverse chronological order, meaning the channel that most recently received a message appears at the top of the list. The channel order is automatically updated in the local cache when a new message arrives.
- Checks if there are more channels to load.
Dispose of the collection
ChannelCollection has the
remove() method that clears all the channels managed by the collection and stops the synchronization process of the collection.
On the other hand, local caching uses the
dispose() method to clear the existing channel list. This method should be called when the user closes the channel list so that the
groupChannelCollectionHandler stops making changes to the channel list view.