Introduction to XML in Flash
       by senocular

White Space in Loaded XML
There is a certain XML option concerning loaded XML that should not go without mention. That is the option to ignore extraneous white space between elements in an XML document. This is determined by an ignoreWhite property of an XML instance.

my_xml.ignoreWhite = true;

What this does is prevents white space such as tabs and spaces used in formatting in your XML to be interpreted as text nodes which Flash likes to do (white space is text too right?). For example. How many child nodes does the happy element have here:

<joy />

If you said three, then you were right! The happy element has one child element, joy, and two text nodes; a newline + tab text node before joy and another newline text node following it. This effect is generally not desired as such white space is meant solely for formatting purposes. By default, the ignoreWhite property for any XML instance in Flash is set to false, so you may want to get into the habit of setting it to true immediately after creating an XML instance if you don't want such white space to be considered text elements. Here it is applied to the previous example used to load my_documents.xml:

var my_xml = new XML();
my_xml.ignoreWhite = true;
my_xml.onLoad = function(success){
if (success){

The ignoreWhite property should be set before XML is loaded as it effects the parsing process. It won't change existing XML within an XML instance.

Note: ignoreWhite only removes white space between elements, this doesn't not include any white space that makes up valid text nodes, even that which is used for formatting them.

Tracing XML
If you've tried the above script, you'll notice that the XML instance traces out the entire XML document it contains when passed to a trace command. Many objects in Flash put "[object Object]" in the output window when traced. The XML object, however, has a unique toString method (the method used by objects represent themselves when trace needs to show it in the output window) that overrides the "[object Object]" with the string representation of the actual XML contents. When you set ignoreWhite to true, you can see in a trace how the XML's structure has changed as a result of that property. For example, the happy-joy XML with ignoreWhite set to true would trace "<happy><joy /></happy>." Later, we'll show you how you can make a toString-esque method that can effectively reverse this process.


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