That line isn’t in my example. It may have been in an earlier, obsolete comment. What happens when you run this code using Flex 4.0.0.10008 or later?

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/08/02/using-the-beta-gumbo-sdk-in-flex-builder-3/ -->
<s:Application name="Gumbo_SDK_test"
        xmlns:fx="http://ns.adobe.com/mxml/2009"
        xmlns:s="library://ns.adobe.com/flex/spark"
        xmlns:mx="library://ns.adobe.com/flex/halo">
 
    <s:Group id="group"
            horizontalCenter="0" verticalCenter="0">
        <s:Rect id="rect"
                width="120" height="60">
            <s:fill>
                <s:SolidColor color="red" alpha="0.2" />
            </s:fill>
            <s:stroke>
                <s:SolidColorStroke color="black" weight="4" />
            </s:stroke>
        </s:Rect>
        <s:RichText id="textGraphic"
                    color="#000000"
                    fontFamily="Arial"
                    fontWeight="bold"
                    horizontalCenter="0" verticalCenter="0">
            <s:content>{Capabilities.version}</s:content>
        </s:RichText>
    </s:Group>
 
    <mx:Label text="I'm a Halo Label component!" />
 
</s:Application>

Peter

I updated the example above to work in newer Flex 4 builds. I tested it w/ Flex SDK 4.0.0.10008, but it should work on 4.0.0.7219 also.

Peter

You can download nightly versions of the Flex 3 SDK and Flex 4 SDK from the Adobe Open Source site at http://opensource.adobe.com/wiki/display/flexsdk/Download+Flex+3 and http://opensource.adobe.com/wiki/display/flexsdk/Download+Flex+4.

You can download the latest trial version of Flash Builder 4 (formerly Flex Builder) from the Adobe Labs site at http://labs.adobe.com/technologies/flashbuilder4/, although nightly versions of Builder are not available. And, if you have a valid Flex Builder 3 license, you can watch http://www.adobe.com/go/flashbuilderextension to request a serial number to extend the Flash Builder 4 trial period.

Peter

But the SDK recently underwent a big rename (see the “Dropping the Fx Prefix” page on the opensource.adobe.com site for more details), so all these old Gumbo examples will ultimately be rewritten so they’ll compile with the latest nightly Flex Gumbo SDKs).

Peter

I guess my point is that, when, using the example above with both namespaces,
<FxButton label=”Gumbo Button”/>
<mx:Button label=”Halo Button”/>
would be exactly the same as:
<mx:FxButton label=”Gumbo Button”/>
<Button label=”Halo Button”/>

what’s the point in using both? I guess the fact that the majority of the discussion in this topic is pertaining to the design view, which I personally have never used, may be in some way relevant. However, as far as straight coding is concerned I’d recommend just using one namespace or the other, just to keep yourself sane.