Comments on: E4X String Parser

By: betabong

betabong — Fri, 21 Aug 2009 16:35:02 +0000

Leonardo, I see your problem. My E4X parser doesn’t (yet) support namespaces. It’s mainly because I didn’t really need it for my own purposes, but also because I think namespaces are a pain in the ass to handle. What I often do, is to just get rid of them:

public static function removeNamspaces( xml : XML ):XML {
	return XML( removeNamspacesFromString( xml.toXMLString() ) );
}
 
public static function removeNamspacesFromString( value : String ):String  
{  
    value = value.replace(removeNS1, "");  
    var attrs:Array = value.match(removeNS2);  
    value = value.replace(removeNS2, "%attribute value%");  
    value = value.replace(removeNS3, "$1");  
    while (value.indexOf("%attribute value%") &gt; 0)  
    {  
        value = value.replace("%attribute value%", attrs.shift());  
    }  
    return value;  
} 
 
private static var removeNS1:RegExp = /xmlns[^"]+\"[^"]+\"/g;
private static var removeNS2:RegExp = /\"[^"]*\"/g;
private static var removeNS3:RegExp = /(<\/?|\s)\w+\:/g;

I admit: this is not a beautiful solution. But it works for most cases. Call me lazy ;)

By: Leonardo Diaz

Leonardo Diaz — Fri, 21 Aug 2009 16:21:06 +0000

Sorry to “spam” your comment section, but this article is one tof the best and on google one of the first results, so I think this one last comment will help others. All the “problems” I’ve got are nicely explained here http://www.senocular.com/flash/tutorials/as3withflashcs3/?page=4

A great resource to fully understand E4X, I think it’ll help you to update your app to dynamically load the namespaces on the xml (that would be awesome), and add an option to filter by using them.

By: Leonardo Diaz

Leonardo Diaz — Fri, 21 Aug 2009 15:53:55 +0000

Hi, well I tried more examples and googled and found that the problem is the default namespace. with the code added on my last comment (just change the [ for the ;> symbol) it works just by deleting the default namespace (xmlns=”urn:mpeg:schema:2001″), now I’m facing a different problem, and it’s how to filter nodes by its params when they are defined using xsi:, for example some elements on the mpeg7 especification has a defined type (MultimediaContent xsi:type=”AudioVisualType” or MultimediaContent xsi:type=”AudioType”) or MultimediaContent xsi:type=”VisualType” ) if I use the e4x filter ..MultimediaContext.(@xsi:type==”AudioType”) it does not work, but if the nodes defines the params just as type=”" (not xsi:type=”") then a normal expression ..MultimediaContext.(@type==”AudioType”) works as expected.

…By the way your online parser has help me a lot, i’d be crying by just debugin the code and e4x expressions.

By: betabong

betabong — Fri, 21 Aug 2009 09:01:36 +0000

Namespaces are not easy to come by, that’s for sure. Still… what exactly doesn’t work? Can you provide me the example, so I can double check with my code?

By: Leonardo Diaz

Leonardo Diaz — Fri, 21 Aug 2009 05:34:27 +0000

opps for the las comment, it did not parse the xml code, I’m trying with some mpeg7 document like this one:
[Mpeg7 xmlns:mpeg7="urn:mpeg:schema:2001"
xmlns="urn:mpeg:schema:2001"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xml="http://www.w3.org/XML/1998/namespace"
xsi:schemaLocation="urn:mpeg:schema:2001 XMLSchema/Mpeg7-2001.xsd "]

[Description type="ContentEntityType"]
[MultimediaContent type="AudioVisualType"]
[AudioVisual]

[MediaInformation]

[/MediaInformation]

[/AudioVisual]
[/MultimediaContent]
[/Description]
[/Mpeg7]

if you delete all the extra params on the mpeg7 it works, but like this, it does not.

By: Leonardo Diaz

Leonardo Diaz — Fri, 21 Aug 2009 05:23:39 +0000

A great tool, but I haven't been able to make it work with xml code that defines namespaces and xsd like this for example: test it works without the namespace and all that stuff on the mpeg7 element Any advice??

By: David

David — Tue, 11 Aug 2009 22:17:50 +0000

Thanks! This was just what I needed.