Docs API Reference

CustomXmlPart.addHandlerAsync method

Adds an event handler for a CustomXmlPart object event.

Hosts: Word
Available in Requirement set
Added in 1.1
customXmlPart.addHandlerAsync(eventType, handler [, options], callback);


Name Type Description Support notes
eventType EventType Specifies the type of event to add. Required. For a CustomXmlPart object event, the eventType parameter can be specified as Office.EventType.DataNodeDeleted, Office.EventType.DataNodeInserted, Office.EventType.DataNodeReplaced, or the corresponding text values of these enumerations.
handler object The event handler function to add, whose only parameter is of type NodeDeletedEventArgs, NodeInsertedEventArgs, or NodeReplaceEventArgs. Required.
options object Specifies any of the following optional parameters.
asyncContext array, boolean, null, number, object, string, or undefined A user-defined item of any type that is returned in the AsyncResult object without being altered.
callback object A function that is invoked when the callback returns, whose only parameter is of type AsyncResult.

Callback Value

When the function you passed to the callback parameter executes, it receives an AsyncResult object that you can access from the callback function's only parameter.

In the callback function passed to the addHandlerAsync method, you can use the properties of the AsyncResult object to return the following information.

Property Use to...
AsyncResult.value Always returns undefined because there is no data or object to retrieve when adding an event handler.
AsyncResult.status Determine the success or failure of the operation.
AsyncResult.error Access an Error object that provides error information if the operation failed.
AsyncResult.asyncContext Access your user-defined object or value, if you passed one as the asyncContext parameter.


You can add multiple event handlers for the specified eventType as long as the name of each event handler function is unique.


function addNodeInsertedEvent() {
    Office.context.document.customXmlParts.getByIdAsync("{3BC85265-09D6-4205-B665-8EB239A8B9A1}", function (result) {
        var xmlPart = result.value;
        xmlPart.addHandlerAsync(Office.EventType.DataNodeInserted, myHandler);
function myHandler(eventArgs) {
            write("A node has been inserted.");
// Function that writes to a div with id='message' on the page.
function write(message){
    document.getElementById('message').innerText += message;

Support details

A capital Y in the following matrix indicates that this method is supported in the corresponding Office host application. An empty cell indicates that the Office host application doesn't support this method.

For more information about Office host application and server requirements, see Requirements for running Office Add-ins.

Office for Windows desktop Office Online (in browser) Office for iPad
Word Y Y
Available in requirement sets CustomXmlParts
Minimum permission level ReadWriteDocument
Add-in types Task pane
Library Office.js
Namespace Office

Support history

Version Changes
1.1 Added support for Word in Office for iPad.
1.0 Introduced