The onauxclick property of the GlobalEventHandlers mixin is an event handler for processing auxclick events.

The auxclick event is raised when a non-primary button has been pressed on an input device (e.g., a middle mouse button). It fires after the mousedown and mouseup events, in that order.

functionRef is a function name or a function expression. The function receives a MouseEvent object as its sole argument. Within the function, this will be the element upon which the event was triggered.

Only one onauxclick handler can be assigned to an object at a time. You may prefer to use the EventTarget.addEventListener() method instead, since it's more flexible.

In this example we define functions for two event handlers — onclick and onauxclick. The former changes the color of the button background, while the latter changes the button foreground (text) color. You can see the two functions in action by trying the demo out with a multi-button mouse (see it live on GitHub; also see the source code).

var button = document.querySelector('button');
var html = document.querySelector('html');

function random(number) {
  return Math.floor(Math.random() * number);
}

button.onclick = function() {
  var rndCol = 'rgb(' + random(255) + ',' + random(255) + ',' + random(255) + ')';
  button.style.backgroundColor = rndCol;
};

button.onauxclick = function() {
  var rndCol = 'rgb(' + random(255) + ',' + random(255) + ',' + random(255) + ')';
  button.style.color = rndCol;
}

• auxclick event
• Related event handlers
  • GlobalEventHandlers.onclick
  • GlobalEventHandlers.ondblclick