ActionScript: The Definitive Guide

Name

XML.onLoad( ) Event Handler — executed when external XML data has been loaded and parsed

Availability

Flash 5

Synopsis

XMLdoc.onLoad(success)

Arguments

success

A Boolean value indicating whether loading was successful (true) or failed (false).

Description

The onLoad( ) handler of XMLdoc is automatically executed whenever an external XML file is loaded into XMLdoc via the load( ) or sendAndLoad( ) methods. By default, the onLoad( ) handler of an XML document object is an empty function. To use onLoad( ), we assign it a callback handler (i.e., a custom-made function). For example:

myDoc = new XML( );
myDoc.onLoad = handleLoad;
function handleLoad (success) {
  // Process XML as desired here... 
}

We rely on onLoad( ) events to tell us when it’s safe to process XMLdoc. If onLoad( ) is triggered, we know that the loading and parsing of external XML data have completed, so we may safely access that loaded content. The onLoad( ) handler, hence, alleviates the need to write preloading code to wait for data to arrive after the invocation of an XML load( ) function. For example, in the following code we load an XML document, and then we wait for our custom handleLoad( ) function to be automatically executed when loading completes. If loading was successful, we process our XML content with the display( ) function. Otherwise, we show an error message by executing the display( ) function. (The displayProduct( ) and displayError( ) functions are custom functions that you’ve presumably written to display ...