FX S MX in Flex

Notes are integrated from other places and are for informational purposes only.

The original Flex build 4 has three namespace fx,mx,s, one for each of the three:

xmlns:fx= "Http://ns.adobe.com/mxml/2009″
xmlns:mx= "Library://ns.adobe.com/flex/halo"
xmlns:s= "Library://ns.adobe.com/flex/spark"

MX is the basic package, FX is an expansion pack, the namespace FX represents the Mxml language features and the compiler directives in Flex 4.
The namespace s refers to all new spark visualizer components that are included in Flex 4.
Namespace MX as a representative of the Flex 3 Halo component Library, is the MX library used by FLEX3.

<MX: Can not nest in <s: Inside otherwise will error.

1, xmlns:fx= "Http://ns.adobe.com/mxml/2009″
The FX namespace contains the ActionScript top-level elements and tags built into the mxml compiler.

The former ActionScript top-level element refers to the object, number, Boolean, and array objects, and so on, in the top-level pack of Adobe Flex 4 Beta Language Reference (top Level), you can view the full top element. The latter tags built into the Mxml compiler include <fx:Script>, <fx:Declarations>, <fx:Style>, and so on, in the Adobe Flex 4 Beta Language Reference "MXML only Tags" in the Appendix (appendixes) can see the full compiler element. It is important to note that this namespace does not contain the Halo and spark components (Halo is a previous version of the component library, and Spark is the new component library of Flex 4). The "mxml-2009-manifest.xml" file can be found under the Flash Builder installation directory (for example, My computer is C:\Program files\adobe\flash Builder beta\sdks\4.0.0\ Frameworks\mxml-2009-manifest.xml), this XML file describes the complete ActionScript top-level class. You can note, however, that it does not contain the Mxml compiler tag, because these tags are built into the Mxml compiler.

2, xmlns:mx= "Library://ns.adobe.com/flex/halo"
The MX namespace contains the components that are placed in the mx.* package, flex charts, Flex data visualization components, and so on. If you're familiar with Flex 3, you're not a stranger to the components in the MX pack. The "halo-manifest.xml" file can be found under the installation directory of the Flex 4 SDK (for example, My computer is C:\Program files\adobe\flash Builder beta\sdks\4.0.0\frameworks\ Halo-manifest.xml), this XML file lists all the components.

3, xmlns:s= "Library://ns.adobe.com/flex/spark"
The S namespace is a novelty, and the components in the spark.* package are in this namespace, not just the spark package, but also the text framework class of the flashx.* package. This namespace contains a number of RPC classes, such as the WebService, Httpservice, and remoteobject components, which are also under the MX namespace, meaning that when you create these components, you can use either the "S:" prefix or the "MX:" prefix. In fact, not only do these RPC components share two namespaces, such as the graphics, effect, and state classes are also common S and MX namespaces. Open the Spark-manifest.xml file in the Flex 4 SDK installation directory to see the complete spark component.

FX S MX in Flex