This API is available on Firefox OS for privileged or certified applications only.


The onerror property is used to specify a callback handler to deal with errors from the server socket. This callback is called each time the listen of a server socket is aborted.

The data attribute of the event object passed to the onerror handler is a string describing the error.


instanceOfTCPServerSocket.onerror = funcRef

Where funcRef is a function to be called on errors.

This callback function will get an event object as its first parameter with a data property which is a string.


var server = navigator.mozTCPSocket.listen(-1);

server.onerror = function (evt) {
  var error =;



Not part of any specification yet; however, this API is discussed at W3C as part of the System Applications Working Group under the Raw Sockets proposal.

See also