Broadcast helpers

Including Hibiki::Rails::Channel also brings in a small set of rendering helpers for the Turbo-broadcast transport: thin wrappers over Turbo::StreamsChannel, all bound to the channel’s stream_name, so a render effect reads as one line of intent:

def build_graph
  @count = Hibiki::State.new(0)

  Hibiki::Effect.new do
    broadcast_replace target: "count", partial: "counter/count",
                      locals: { count: @count.value }
  end
end

They are private on purpose — a public method on a channel becomes a client-invocable action, and nobody wants the browser calling broadcast_replace directly.

broadcast_replace(target:, **rendering)

Replace the element with DOM id target. The rendering options are whatever Turbo’s renderer accepts: partial:/locals:, a raw html: string (which is how Hibiki::Phlex.render_effect pairs with it), and so on.

broadcast_morph(target:, **rendering)

Same replace, but delivered as a Turbo 8 morph (method="morph"). Morphing patches the existing DOM instead of swapping the subtree, so focus, scroll position, and unchanged elements survive the update. Prefer it for fragments the user interacts with; plain broadcast_replace is fine for display-only fragments.

broadcast_refresh

Tell the page to refresh itself — the Turbo 8 “morph-everything” style, where the server doesn’t render fragments at all and the page just re-fetches and morphs. Pair it with debouncing when many writes should mean one refresh.

broadcast_refresh_effect(wait: 0.25) { ...read signals... }

The morph-everything style as one call: creates an effect that tracks whatever signals the block reads and answers changes with a debounced broadcast_refresh. Hibiki.batch already coalesces the writes within one action; the debounce covers the cross-action case — a burst of quick actions produces one page refresh per wait window, not one per action. The initial dependency-collecting run broadcasts immediately, like every effect’s first run.

def build_graph
  @list = TodoList.new
  broadcast_refresh_effect { @list.items }  # any change to items → one refresh per burst
end

Where these broadcasts go

All helpers broadcast to the channel’s stream_name, which defaults to [channel_name, cid] — matching the page’s <%= turbo_stream_from channel_name, cid %>. Override stream_name on the channel if the page listens on different streamables. On the transmit transport none of this is involved: render effects call transmit({ html: }) on the subscription itself (see The JS client).