Extensible Application Markup Language

Infobox file format
name = Extensible Application Markup Language (XAML)
extension = .xaml
mime = application/xaml+xml
owner = Microsoft
genre = User interface markup language
container for =
contained by =
extended from = XML
extended to =

Extensible Application Markup Language (XAML, pronounced "zammel" IPA| [ˈzæmɫ] ) is a declarative XML-based language created by Microsoft which is used to initialize structured values and objects. It is available under Microsoft's Open Specification Promise. [ [http://www.sdtimes.com/(X(1)S(kw21wu45u03kzpnafqlanyiy))/content/article.aspx?ArticleID=31886&AspxAutoDetectCookieSupport=1 Microsoft adds XAML to 'Open Specification' list - Software Development Times On The Web ] ] The acronym originally stood for Extensible Avalon Markup Language - "Avalon" being the code-name for Windows Presentation Foundation (WPF). [ [http://www.windows-now.com/blogs/rrelyea/archive/2004/01.aspx Rob Relyea : January 2004 - Posts ] ]

Overview

XAML is used extensively in .NET Framework 3.0 technologies, particularly Windows Presentation Foundation (WPF) and Windows Workflow Foundation (WF). In WPF, XAML is used as a user interface markup language to define UI elements, data binding, eventing, and other features. In WF, workflows can be defined using XAML.

XAML elements map directly to Common Language Runtime object instances, while XAML attributes map to Common Language Runtime properties and events on those objects. XAML files can be created and edited with visual design tools such as Microsoft Expression Blend, Microsoft Visual Studio, and the hostable Windows Workflow Foundation visual designer. They can also be created and edited with a standard text editor, a code editor such as XAMLPad, or a graphical editor such as Vectropy.

Anything that is created or implemented in XAML can be expressed using a more traditional .NET language, such as C# or Visual Basic.NET. However, a key aspect of the technology is the reduced complexity needed for tools to process XAML, because it is based on XML [cite web
url=http://msdn2.microsoft.com/en-us/library/ms788723.aspx
title=XAML Syntax Terminology
publisher=Microsoft Corporation] . As a result, a variety of products are emerging, particularly in the WPF space, which create XAML-based applications. As XAML is simply based on XML, developers and designers are able to share and edit content freely amongst themselves without requiring compilation. As it is strongly linked to the .NET Framework 3.0 technologies, the only fully compliant implementation as of today is Microsoft's Fact|date=April 2008.

Technology

A XAML file can be compiled into a .baml (Binary XAML) file, which may be inserted as a resource into a .NET Framework assembly. At run-time, the framework engine extracts the .baml file from assembly resources, parses it, and creates a corresponding WPF visual tree or workflow.

When used in Windows Presentation Foundation, XAML is used to describe visual user interfaces. WPF allows for the definition of both 2D and 3D objects, rotations, animations, and a variety of other effects and features.

When used in Windows Workflow Foundation contexts, XAML is used to describe potentially long-running declarative logic, such as those created by process modeling tools and rules systems. The serialization format for workflows was previously called XOML, to differentiate it from UI markup use of XAML, but now they are no longer distinguished. However, the file extension for files containing the workflow markup is still "XOML". [ [http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=218938&SiteID=1#221631 MSDN forum post by the WF product manager] ] [RuleML and BPEL are other examples of XML-based declarative logic languages]

Templates

XAML uses a specific way to define Look and feel called "Template"s, different from the Cascading Style Sheets syntax, but closer to XBL [cite web
url=http://weblogs.asp.net/scottgu/pages/silverlight-tutorial-part-7-using-control-templates-to-customize-a-control-s-look-and-feel.aspx
title=Silverlight Tutorial Part 7: Using Control Templates to Customize a Control's Look and Feel
last=Guthrie|first=Scott
date=2008-02-22
accessdate=2008-03-08] .

Example

This Windows Presentation Foundation example shows the text "Hello World!" in the top-level XAML container called Canvas. Hello World!

The schema (the xmlns="http://schemas.microsoft.com..." part) may have to be changed to work on your computer. Using a schema that Microsoft recommends, the example can also be [Microsoft XAML Overview page at [http://msdn.microsoft.com/en-us/library/ms752059.aspx#xaml_files XAML Overview (Root element and xmlns)] ]

Hello World!

This can be integrated into a web page if WPF is installed using XBAPs (XML Browser Applications) which are compiled applications running in a sandboxed environment hosted within the browser. Another way is to use the Silverlight plugin. The code can not be included directly in an html page; rather it must be loaded into the page via JavaScript. If .NET 3.0 or later is installed, loose XAML files can also be viewed on their own in a compatible web browser (including Internet Explorer and Firefox) in conjunction with the .NET Framework 3.0, without the need for the Silverlight plugin. [ [http://msdn.microsoft.com/en-us/library/aa480223.aspx#wpfandwbas_topic6 Windows Presentation Foundation on the Web: Web Browser Applications - MSDN] ] Loose XAML files are markup-only files limited to defining the visual content to be rendered. They are not compiled with an application.

The "MySilverlight.js" file must contain the code that loads the above XAML code (as an XML file) under the "MySilverlight" html element.

Criticism

The European Committee for Interoperable Systems (a coalition of Microsoft's largest competitors [cite web
url=http://www.itwire.com/content/view/8988/53/
title=Microsoft runs into EU Vista charges
publisher=itwire.com
date=2007-01-28
accessdate=2008-04-16] ) argues that Microsoft's use of XAML in its Silverlight product aims to introduce content on the web that can only be served from the Windows platform.

However, XAML is viewable in non-Microsoft browsers on Windows and Mac, and Microsoft provides direct support for the development of a Silverlight viewer for GNU/Linux called Moonlight [cite web
url=http://blogs.zdnet.com/microsoft/?p=695
title=Microsoft officially ‘extends support’ for Novell’s Silverlight Linux port
publisher=zdnet.com
last=Foley|first=Mary Jo
date=2007-09-25
accessdate=2007-10-13] .

References

ee also

* List of user interface markup languages
* Comparison of user interface markup languages
* JavaFX
* Layout manager
* ZUML
* NextStep/Cocoa Interface Builder

External links

* [http://www.infragistics.com/design/Fireworks_XAML_Exporter.aspx Adobe Fireworks to XAML Exporter (free)]
* [http://www.xaml.net XAML DOT NET - A website with useful information about XAML.]
* [http://msdn2.microsoft.com/en-us/library/ms754130.aspx WPF SDK] Microsoft Developer Network's top-level portal to the Windows Presentation Foundation SDK which documents WPF technologies including XAML.
* [http://windowssdk.msdn.microsoft.com/en-us/library/ms752059.aspx Microsoft XAML overview]
* [http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnintlong/html/longhornch03.asp?frame=true XAML Controls from Microsoft Longhorn Developer Introduction]
* [http://xaml.sourceforge.net United XAML Initiative] - Open Source XAML Alternatives
* [http://www.netfxguide.com/guide/xaml.aspx XAML page on NetFXGuide.com] A selection of categorized resources on XAML.
* [http://www.learnwpf.com/ LearnWPF] Website to learn WPF
* [http://xml.coverpages.org/ms-xaml.html Website resource for markup language technologies]
* [http://www.xamlarchive.com Free XAML Designs Website]
* [http://www.team-mediaportal.com Mediaportal, an Open source mediacenter application which includes an opensource xaml/wpf skinengine]
* [http://www.shaxam.com A LightWave 3D > XAML object converter]
* [http://www.codeplex.com/dbxamlword Dylan's XAML Word (Word Processor) on Codeplex]
* [http://www.3dpaintbrush.com/content/xaml.aspx 3DPaintBrush - Create XAML from 3D models] From 3DS, SketchUp, STEP/IGES/OBJ, DXF/DWG models.