Broadcasting

Broadcasting pushes application events to named channels so listeners (in-process websocket subscribers, tests, or a future network driver) can react.

Register

Kotlin

app.register(BroadcastServiceProvider())

Config keys:

Key	Meaning
broadcasting.default	Connection name (default log)
broadcasting.connections.{name}.driver	log, null / none, or websocket / ws

ShouldBroadcast events

class OrderShipped : ShouldBroadcast {
    override fun broadcastOn() = listOf(Channel.publicChannel("orders"))
    override fun broadcastAs() = "order.shipped"
    override fun broadcastWith() = mapOf("id" to 42)
}

Broadcast.event(OrderShipped())

Java

Broadcast.event(new OrderShipped());

Ad-hoc broadcasts

Kotlin

Broadcast.to(Channel.publicChannel("orders"), Channel.privateOf("user.1"))
    .event("order.shipped", mapOf("id" to 42))

Drivers

Driver	Behavior
log	Stores payloads in memory (Broadcast.manager().log().messages()) — ideal for tests
null / none	No-op
websocket / ws	In-process fan-out to registered connection handlers (WebsocketBroadcaster)

Websocket (in-process)

WebsocketBroadcaster keeps a channel → listener map. Subscribe locally, then broadcast; each distinct connection receives the payload once even if it listens on multiple matching channels. There is no network socket in this release — the driver is the websocket shape (subscribe + fan-out) for tests and Java callers, ready to wrap a Netty endpoint later.

val ws = Broadcast.manager().websocket()
ws.subscribe("orders") { channels, event, payload ->
    // deliver to a client connection
}
app.config.set("broadcasting.default", "websocket")
Broadcast.event(OrderShipped())

Java

WebsocketBroadcaster ws = Broadcast.manager().websocket();
ws.subscribe("orders", (channels, event, payload) -> { /* … */ });