This API is available on Firefox OS for internal applications only.

The onholding property of the Telephony interface specifies an event listener to receive holding events. These events occur when an action is taken to put the call group on hold (i.e. the TelephonyCallGroup.hold() method is called.)


myTelephonyCallGroup.onholding = function() { ... };

These events are of type CallEvent.


// Telephony object
var tel = navigator.mozTelephony;

// Make two calls; assume they are both answered
var call1, call2;
tel.dial(number1).then(call => call1 = call);
tel.dial(number2).then(call => call2 = call);

// Add both calls to the conference call
// Two entries will appear in conference.calls (call1, call2)
// but nothing in tel.calls
var conference = tel.conferenceGroup;
conference.add(call1, call2);

conference.onholding = function() {
  // Do something when an attempt is
  // made to hold the conference call


Specification Status Comment
Web Telephony Draft Draft

Browser compatibility

For obvious reasons, support is primarily expected on mobile browsers.

Supported in Firefox OS 1.0.1.

See also