DOM_Element::getElementsByTagName() question

[Gadi Shiloah <ga...@managair.net>]

Hello all,

I am a bit new at this, but here goes...

I have a sub-tree that looks like this:

<parent>
    <child0 data="x"/>
    <child1 data="y"/>
    <child2 data="z"/>
    <!-- continues to childN -->
</parent>   

My goal is to obtain the contents of the data attribute of each child.

In order to do so, I use the following code:

DOM_Element parentElem; //refers to <parent>
DOM_Element childElem;
DOM_NodeList List;
DOMString strTag;    //to hold the sought tag name

//strTag is initialized to "child0"
List=parentElement.getElementsByTagName(strTag);


while(List!=0) //(i hoped...) List will turn null at the 1st time strTag matches no tag name
{
 childElement=(DOM_Element &)List.item(0);

 //get the attribute's value and do something

 //strTag is assigned the tag name of the next expected child i.e. child1, then child2, etc.
 List=parentElement.getElementsByTagName(strTag);
}


Unfortunately, List does not become null when i call 

    List=parentElement.getElementsByTagName(strTag);

with an invalid strTag, and while's condition never evaluates to false, and
I get an exception thrown pretty soon after that happens.

The documentation says only this:

DOM_NodeList DOM_Element::getElementsByTagName (const DOMString & name)const  
 
   Returns a NodeList of all descendant elements with a given tag name, in the order in which they would be encountered in a preorder traversal of the DOM_Element tree. 

Parameters: 
name   The name of the tag to match on. The special value "*" matches all tags.  

Returns: 
A list of matching DOM_Element nodes.

I thought of using an additional DOM_Node and checking it's type at the beggining of each iteration, breaking once it is not ELEMENT_NODE. 

But isn't there another way to tell if the sought child node was found?

Thanks in advance, Gadi.