This feature is not on a current W3C standards track, but it is supported on the Firefox OS platform. Although implementations may change in the future and it is not supported widely across browsers, it is suitable for use in code dedicated to Firefox OS apps.
A reference to a function to be called to handle the Telephony API's
connecting event. This event occurs when the call has finished dialing but before the connection is made. The event handler is called with a
CallEvent as its only parameter.
instanceOfTelephonyCall.onconnecting = funcRef;
This is a non standard implementation, but it is discussed at W3C as part of the System Application Working Group.
|Web Telephony API||Editor's Draft||Editor Draft (WIP).|
For obvious reasons, support is primarily expected on mobile browsers.
|Feature||Chrome||Firefox (Gecko)||Internet Explorer||Opera||Safari|
|Basic support||Not supported||Not supported||Not supported||Not supported||Not supported|
|Feature||Android||Firefox Mobile (Gecko)||IE Mobile||Opera Mobile||Safari Mobile|
|Basic support||Not supported||12.0 (12.0)||Not supported||Not supported||Not supported|