Phoenix controller helpers for StarView.

Use use StarView, :controller from your web module after use Phoenix.Controller has been applied:

def controller do
  quote do
    use Phoenix.Controller, formats: [:html]
    use StarView, :controller
  end
end

Controllers implement StarView.StarView:

@impl StarView
def handle_event("increment", signals, conn), do: ...

assign/3 vs signal/3

• assign/3 sets a Plug connection assign. Function components can read it via @key, but it is never sent to the browser.
• signal/3 does assign/3 and tracks the key for automatic flushing. Function components can read it, and the dispatcher sends it to the Datastar client as a signal patch.