Event Handling

The state layer provides a way to be notified about state updates easily. However, it’s also possible to watch for WebSocket events directly by collecting an events flow, should you need it.

Observing events

The FeedsClient exposes an events property to get a flow of events:

feedsClient
    .events
    .collect { event ->
        // Handle the event types you care about
        when (event) {
            is ActivityAddedEvent -> {
                println("New activity added: ${event.activity.text}")
            }
            is CommentAddedEvent -> {
                println("New comment added: ${event.comment.text}")
            }
            is FollowCreatedEvent -> {
                println("New follow created: ${event.follow.targetFeed}")
            }
            else -> {
                println("Received event: ${event::class.java.simpleName}")
            }
        }
    }

Leveraging the Flow API

With the events coming as a Flow, no special knowledge is needed to get started. You can use all the power of Kotlin's coroutines and Flow API to handle events in a way that suits your use cases.

For example, if you want to only listen for a specific event type, like new activities added, you can use the filterIsInstance operator:

feedsClient
    .events
    .filterIsInstance<ActivityAddedEvent>()
    .collect { event ->
        println("New activity added: ${event.activity.text}")
    }

Handling backpressure

If your event processing is slow, you might want to add explicit backpressure handling because the events flow will drop events if the consumer cannot keep up.

For example, you can use the buffer operator and specify your desired strategy:

feedsClient
    .events
    .buffer(capacity = 100, onBufferOverflow = BufferOverflow.DROP_OLDEST)
    .collect { event ->
        // Process the event
    }

Available Event Types

Below is a table of all available events:

Server-side webhooks

Webhooks are configured with your API secret, so they belong on your backend rather than in the app you ship. Setting up an endpoint, verifying signatures, retries and event failover are covered under Event handling in the server-side docs, with the full transport reference in the platform webhooks guide.