EventPayload
Passed to the host's JoyDomEventHandler when a bound event fires. Mirrors React's EventBinding dispatch (js/react/src/types.ts): the spec carries no DOM event, so instead of a SyntheticEvent the payload names the type kind alongside the bound name and its params.
target identifies the node the event fired on — the joy-dom analog of the DOM event.target. It is always present (every dispatch has an originating node), even when that node has no id.
params is always the binding's static params exactly as authored in the spec JSON; payload is runtime data a custom component passed to ComponentScope.emit (the DOM analog is CustomEvent.detail). The two are never merged, so the handler can always tell author data from component data.
Constructors
Functions
The runtime data a custom component passed to emit — what {"$event": …} reads, before the binding's own params are merged over it.
The renderer's EventPayload as the binding the interpreter runs.