This page provides a guide that demonstrates how to integrate Sendbird SyncManager onto a client app. Sendbird SyncManager can be installed through
Gradle. Start building the add-on to your Chat SDK by clicking the Download SyncManager button below.
Note: Sendbird Chat SDK is required in order to use Sendbird SyncManager because it is an add-on feature.
Installing the SyncManager SDK is simple if you're familiar with using external libraries or SDKs. First, add the following code to your root
Note: Make sure the above code block isn't added to your module
Then, add the dependency to your module
Note: SyncManager SDK versions
1.1.30or lower can be downloaded from JCenter until February 1, 2022. SDK versions higher than
1.1.30will be available on Sendbird's remote repository.
How it works
SyncManager is designed to simplify the process of integrating chat in your Android client app by leveraging local caching. While Sendbird Chat SDK for Android is highly customizable with a number of atomic features, SyncManager facilitates SDK integration by managing most background operations needed to run chat in your Android client app.
SyncManager has an event-driven architecture that updates the chatting view based on data events. Events received through the WebSocket connection as well as processed data in the cache are delivered to the client app by the SyncManager’s collection handlers and can be leveraged when implementing your view.
As a key component that can be used for view implementation, the
Collection holds items that comprise channel or message data. In your view, a collection instance can be binded to an event handler to subscribe to events. In the callbacks of the event handler, you can implement what jobs to execute when a specific type of event happens. The following shows a simple example of how you can create a channel collection and bind it to a collection event handler:
Background sync is a feature of SyncManager that automatically stores data fetched from Sendbird server in the local cache. When a collection is created, the background sync process starts running with the given conditions. Background sync should follow the lifecycle of a connection: the
pauseSync() method is called when a connection is lost and the
resumeSync() method is called when a connection is established.
For example, even if only 2 out of 12 channels are cached, background sync feeds the uncached Sendbird server data to the chatting view so that all 12 channels are displayed. In order for this to happen, the channel collection’s
fetch() should be called, and the collection brings the insert event for the two channels from the cache. Then, the uncached 10 channels are synchronized through background sync. After synchronization is completed, another insert event is given for the uncached 10 channels. Through this process, all 12 channels are displayed in the view.
Real-time event sync
Real-time event sync is a feature of SyncManager that listens for real-time events received through the WebSocket connection. When an event arrives, SyncManager identifies it, stores it in the cache, and delivers it to the collection handler with the appropriate action such as insert or remove.
SyncManager ensures your client app is operational during offline mode. If background sync isn’t running because a connection with the server hasn’t been established, the view can display cached data provided by SyncManager. Once a connection is re-established, the
resumeSync() resumes background sync for data synchronization.
This section describes how to implement SyncManager in your Android client app.
Initialize and set up the database for SyncManager as below:
Specifies the ID of the user.
Specifies the options for how SyncManager works.
Called after the setup is completed.
SendBirdSyncManager.Options has the following properties:
List of properties
Determines the maximum capacity of messages in a collection related to a chat view. Messages that exceed the maximum capacity are removed. Acceptable values are from 200 to 2,147,483,647. (Default: 2,147,483,647)
Determines the policy for handling failed messages. If delivery of a message fails, SyncManager performs different actions based on the configured policy. Acceptable values are:
Determines the maximum number of attempts to resend a failed message. Resend attempts are stopped for messages that have been resent the maximum number of attempts and they remain as failed. The
Determines the maximum number of failed messages allowed in a channel. SyncManager deletes the earliest failed message and delivers the remove event through the
Determines the number of days to retain failed messages. Once failed messages have been retained for the retention period, they are automatically removed. (Default: 7)
When the Chat SDK is connected to Sendbird server, SyncManager fetches the current user’s chat-related data from the server to update the local cache. This enables SyncManager to synchronize the local cache with the channel and message data.
Additional jobs, which detect changes in connection status and notify SyncManager, are needed when data is fetched from the server through the Chat SDK’s connection event handler: calling the
pauseSync() methods. The
resumeSync() should be called in the
onReconnectSucceeded() to run background processes for data synchronization when connected, whereas the
pauseSync() should be called in the
onReconnectStarted() to pause the background processes when disconnected. Adding and removing the connection handler is suggested to be done in
SendBird.removeAllChannelHandlers()method shouldn’t be called because they remove not only the handlers you’ve added, but also the other handlers internally managed by SyncManager.
Clear local cache
The cache can be cleared regardless of connection to Sendbird server using the
clearCache()is designed for debugging purposes only. Using it for other purposes isn’t recommended.