MIDIOutput: send() method

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

The send() method of the {{domxref("MIDIOutput")}} interface queues messages for the corresponding MIDI port. The message can be sent immediately, or with an optional timestamp to delay sending.

Syntax

send(data)
send(data, timestamp)

Parameters

• data
  • : A sequence of one or more valid MIDI messages. Each entry represents a single byte of data.
• timestamp {{optional_inline}}
  • : A {{domxref("DOMHighResTimestamp")}} with the time in milliseconds when the message should be sent (relative to {{domxref("Performance.timeOrigin")}}).

Return value

None ({{jsxref("undefined")}}).

Exceptions

• {{jsxref("TypeError")}}
  • : Thrown if data is not a valid sequence, or does not contain a valid MIDI message.
• NotAllowedError {{domxref("DOMException")}}
  • : Thrown if data is a system exclusive message, and the {{domxref("MIDIAccess")}} did not enable exclusive access.
• InvalidStateError {{domxref("DOMException")}}
  • : Thrown if the port is disconnected.

Examples

In the following example a middle C note is sent immediately, followed by a note off message one second later.

function sendMiddleC(midiAccess, portID) {
  const noteOnMessage = [0x90, 60, 0x7f]; // Note on middle C, full velocity
  const output = midiAccess.outputs.get(portID);
  output.send(noteOnMessage); // Omitting the timestamp means send immediately.
  output.send([0x80, 60, 0x40], window.performance.now() + 1000.0); // timestamp = now + 1000ms.
}

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}