HTMLElement: command event

{{APIRef("Invoker Commands API")}}

The command event of the {{domxref("HTMLElement")}} interface fires on an element that is controlled via a {{domxref("HTMLButtonElement", "button")}} with valid {{domxref("HTMLButtonElement.commandForElement", "commandForElement")}} and {{domxref("HTMLButtonElement.command", "command")}} values, whenever the button is interacted with (e.g., it is clicked).

Syntax

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

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

oncommand = (event) => { }

Event type

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

{{InheritanceDiagram("CommandEvent")}}

Examples

Basic example

const popover = document.getElementById("mypopover");

// …

popover.addEventListener("command", (event) => {
  if (event.command === "show-popover") {
    console.log("Popover is about to be shown");
  }
});

Event dispatch and cancellation

It is worth pointing out that command events fire on the element being invoked. If the button is clicked, it will first dispatch a click event which, if cancelled, then the command event will not fire and the default behavior will not be run. In addition to cancelling the click event on the button, it is also possible to cancel the command event.

For example:

button.addEventListener("click", (event) => {
  event.preventDefault(); // the `command` event will never fire
});

element.addEventListener("command", (event) => {
  event.preventDefault(); // the `command` event fires but the default behavior is cancelled
});

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• {{domxref("Invoker Commands API", "Invoker Commands API", "", "nocode")}}
• {{domxref("HTMLButtonElement.command")}}
• {{domxref("HTMLButtonElement.commandForElement")}}