[flexcoders] e4x 101 -- Help get it through my thick skull

[David Ham]

Hi,

I'm working with webservice xml data in XML format, and the e4x is
giving me a little trouble. Am I right on these points:

* All e4x operations return an XMLList. I've been trying to get them
to return XML, like:

var theNodeIWant : XML = myDataSet.myElement.(@someAttr == foo)

but it seems this is wrong; I should just expect an XMLList, and even
if I know for sure that the result is one element long, I should just
use the pertinent XML methods on the XMLList, since one-element
XMLLists just pass these calls to the element.

* To test for emptiness or undefined-ness, do I do this:

var theNodeIWant : XML = myDataSet.myElement.(@someAttr == foo)
if ( theNodeIWant.length() == 0 ) {
// e4x query returns no results
}

Is length() the only way to do this, or is there a more accurate way
that would return null or undefined?

I get the sense that e4x is really powerful, but it's kind of
different and it's been busting my balls lately.

Thanks much,

OK
DAH

Re: [flexcoders] e4x 101 -- Help get it through my thick skull

[Mondain]

These references helped me with e4x:
http://developer.mozilla.org/presentations/xtech2005/e4x/
http://www.devx.com/webdev/Article/33393/0/page/2

Paul

On Mon, Mar 24, 2008 at 8:56 AM, David Ham [EMAIL PROTECTED] wrote:

   Hi,

 I'm working with webservice xml data in XML format, and the e4x is
 giving me a little trouble. Am I right on these points:

 * All e4x operations return an XMLList. I've been trying to get them
 to return XML, like:

 var theNodeIWant : XML = myDataSet.myElement.(@someAttr == foo)

 but it seems this is wrong; I should just expect an XMLList, and even
 if I know for sure that the result is one element long, I should just
 use the pertinent XML methods on the XMLList, since one-element
 XMLLists just pass these calls to the element.

 * To test for emptiness or undefined-ness, do I do this:

 var theNodeIWant : XML = myDataSet.myElement.(@someAttr == foo)
 if ( theNodeIWant.length() == 0 ) {
 // e4x query returns no results
 }

 Is length() the only way to do this, or is there a more accurate way
 that would return null or undefined?

 I get the sense that e4x is really powerful, but it's kind of
 different and it's been busting my balls lately.

 Thanks much,

 OK
 DAH

  




-- 
It is difficult to free fools from the chains they revere. - Voltaire

RE: [flexcoders] e4x 101 -- Help get it through my thick skull

[Tracy Spratt]

To get XML from an expression, do:

var theNodeIWant : XML = myDataSet.myElement.(@someAttr == foo)[0];

 

Expressions always return an XMLList.  If no records are found, then the
list has zero length, so using length() is the way to do this.

 

Tracy



From: flexcoders@yahoogroups.com [mailto:[EMAIL PROTECTED] On
Behalf Of David Ham
Sent: Monday, March 24, 2008 11:57 AM
To: flexcoders@yahoogroups.com
Subject: [flexcoders] e4x 101 -- Help get it through my thick skull

 

Hi,

I'm working with webservice xml data in XML format, and the e4x is
giving me a little trouble. Am I right on these points:

* All e4x operations return an XMLList. I've been trying to get them
to return XML, like:

var theNodeIWant : XML = myDataSet.myElement.(@someAttr == foo)

but it seems this is wrong; I should just expect an XMLList, and even
if I know for sure that the result is one element long, I should just
use the pertinent XML methods on the XMLList, since one-element
XMLLists just pass these calls to the element.

* To test for emptiness or undefined-ness, do I do this:

var theNodeIWant : XML = myDataSet.myElement.(@someAttr == foo)
if ( theNodeIWant.length() == 0 ) {
// e4x query returns no results
}

Is length() the only way to do this, or is there a more accurate way
that would return null or undefined?

I get the sense that e4x is really powerful, but it's kind of
different and it's been busting my balls lately.

Thanks much,

OK
DAH