Keith Hair

The XML examples represent a book in a library. However the book has several bookworms in it.
Using E4X we can find these bookworms.

 
<library>
	<book>
<page id="one"/>
		<worm name="Eddy" />
<page id="two"/>
<page id="three">
			<worm name="Lisa"/>
			<worm name="Pete" />
		</page>
<page id="four"/>
	</book>
</library>
 

There are some E4X operators and XML methods to help use do this when combined together:

.. Access all descendants of the XML object.
. Access a property of an Object or XML.
* Wildcard, match any part of the XML.
childIndex() Index number of an XML object relative to its parent node.
name() Name of the XML node.

Return a certain "worm" node at the index it belongs to from its XMLList.
Any nested "worm" node occurrence is also considered.

 
var doc:XML=
<library>
	<book>
<page id="one"/>
		<worm name="Eddy" />
<page id="two"/>
<page id="three">
			<worm name="Lisa"/>
			<worm name="Pete" />
		</page>
<page id="four"/>
	</book>
</library>;
 
//Pick the "worm" node at index 1.
var data:*=doc..*.worm[1];
trace(data.toXMLString());
 
/*=========================================
OUTPUT:
 
<worm name="Lisa"/>			//worm[1]
===========================================*/
 

Delete all "worm" nodes from the xml, even the nested ones.

 
var doc:XML=
<library>
	<book>
<page id="one"/>
		<worm name="Eddy" />
<page id="two"/>
<page id="three">
			<worm name="Lisa"/>
			<worm name="Pete" />
		</page>
<page id="four"/>
	</book>
</library>;
 
delete doc..*.worm;
trace(doc.toXMLString());
 
/*=========================================
OUTPUT:
All "worm" nodes are deleted.
<library>
  <book>
<page id="one"/>
<page id="two"/>
<page id="three"/>
<page id="four"/>
  </book>
</library>
===========================================*/
 

Use E4X filtering with Regular Expressions.
XML methods and Regular Expressions can be used inside parentheses to accomplish E4X filtering.

doc..*.(childIndex()==0 && /library|book/i.test(name())==false)

List all nodes that belong at a given index of their XMLList.

 
var doc:XML=
<library>
	<book>
<page id="one"/>
		<worm name="Eddy" />
<page id="two"/>
<page id="three">
			<worm name="Lisa"/>
			<worm name="Pete" />
		</page>
<page id="four"/>
	</book>
</library>;
 
//----------------------------------------------------
//Get the first node of each list whose name does not
//match the regular expression.
//----------------------------------------------------
var data:*=doc..*.(childIndex()==0 && /library|book/i.test(name())==false);
trace(data.toXMLString());
 
/*=========================================
OUTPUT:
<page id="one"/>
<worm name="Lisa"/>
===========================================*/
 

This entry was posted on Saturday, May 31st, 2008 at 11:54 am and is filed under ActionScript 3, XML.You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.