MIDIAccess: statechange event

{{securecontext_header}}{{APIRef("Web MIDI API")}}

The statechange event of the {{domxref("MIDIAccess")}} interface is fired when a new MIDI port is added or when an existing port changes state.

Syntax

Use the event name in methods like {{domxref("EventTarget.addEventListener", "addEventListener()")}}, or set an event handler property.

addEventListener("statechange", (event) => { })

onstatechange = (event) => { }

Event type

A {{domxref("MIDIConnectionEvent")}}. Inherits from {{domxref("Event")}}.

{{InheritanceDiagram("MIDIConnectionEvent")}}

Event properties

• {{domxref("MIDIConnectionEvent.port")}} {{ReadOnlyInline}}
  • : Returns a reference to a {{domxref("MIDIPort")}} instance for a port that has been connected or disconnected.

Example

The {{domxref("Navigator.requestMIDIAccess()")}} method returns a promise that resolves with a {{domxref("MIDIAccess")}} object. When a port changes state, information about that port is printed to the console.

navigator.requestMIDIAccess().then((access) => {
  access.onstatechange = (event) => {
    console.log(event.port.name, event.port.manufacturer, event.port.state);
  };
});

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}