Skystone Software
http://www.SkystoneSoftware.comSkystone Software is an Echosoft Design Studio, dedicated to the rapid design and development of high-end enterprise application systems built within the Microsoft .NET framework. A software consultancy serving clients primarily in the Hartford, Connecticut area of the United States, Skystone provides rapid and affordable software development and project management.
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Scott Waletzko, founder of Skystone Software, is a Windows and Web programmer and a Microsoft Most Valuable Professional (Visual Developer - Visual Basic) since 2006. Scott has extensive professional experience designing and developing software using C#, Visual Basic (both COM and .NET), HTML, JavaScript, and Flash / ActionScript. |
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Xml Schema - Any Number of Elements in any Order
Published: 10/9/2008 |
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Xml Schema is a powerfule tool that allows data designers to develop their own markup languages (like HTML) using a complex set of definitions and restrictions. It's not, however, always straight forward how the simplest things can be achieved using Xsd. Take, for example, the definition of a subset of elements that can exist beneath a parent element in any order, any combination. Xml Schema provides the xs:sequence, xs:all, and xs:choice elements to allow designers to specify groups of subelements, but it's nto obvious by looking at their descriptions which would facilitate this particular design. Let's look at each in turn:
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xs:sequence
Specifies a specific set of sub elements that should appear in a specific order. -
xs:all
Specifies that any of the elements defined can appear in any order zero or one times. -
xs:choice
Specifies that only one of the elements defined will appear.
So at first look, none of these will allow us to design a subset of elements that can appear in any order, each element appearing any number of times. The key to cracking this puzzle, however, lies with the attributes that can be defined for each of the above elements in the schema document. xs:choice has a "minOccurs" and "maxOccurs" attribute, which basically tells the validating reader that the choice itself can occur more than once. This allows us to specify any number of elements in any order, as follows:
Xml Schema:
<xs:schema id="test" targetNamespace="http://tempuri.org/test.xsd"> <xs:complexType name="testType"> <xs:choice minOccurs="0" maxOccurs="unbounded"> <xs:element name="test1" /> <xs:element name="test2" /> <xs:element name="test3" /> </xs:choice> </xs:complexType> <xs:element name="testType" type="testType" /> </xs:schema>
Sample Xml:
<testType xmlns="http://tempuri.org/test.xsd"> <test3 /> <test2 /> <test1 /> <test2 /> <test2 /> <test2 /> <test3 /> <test2 /> <test1 /> </testType>
2008 Microsoft MVP Award
Sunday, July 1st, 2008
Scott Waletzko has, for the third year in a row, been awarded the distinguished honor of being named a Most Valuable Professional (Visual Developer - Visual Basic) for 2008 by Microsoft!
| Click here to learn more about the MVP Program.Click here to read Scott's profile on the MVP site. |
2007 VBCity .NET Guru of the Year
Monday, December 25th, 2007
Scott Waletzko has been awarded the honor of being voted the 2007 .NET Guru of the Year by the VBCity community members!
| Click here for the announcement of all awards presented.Click here to go to the VBCity forums. |
2007 Microsoft MVP Award
Sunday, July 1st, 2007
Scott Waletzko has once again been awarded the distinguished honor of being named a Most Valuable Professional (Visual Developer - Visual Basic) for 2007 by Microsoft!
| Click here to learn more about the MVP Program.Click here to read Scott's profile on the MVP site. |
Free Online Course: Xml 101
Monday February 5, 2007
This course will serve as an introduction to the usage of Xml as a data definition language within the .NET framework. First we will cover a characterization and history of Xml in order to obtain a base to work from. Then, we will introduce the System.Xml namespace in .NET, which contains all of the objects and functions that .NET users to interact with and create Xml documents.
NOTE: The sample project and code for this course was written using Visual Basic .NET 2005 Express Edition, but all of the Xml concepts and most of the .NET code will apply to previous versions of .NET.
This course is now closed - thanks for everyone who participated!.
2006 Microsoft MVP Award
Saturday, July 1st, 2006
Scott Waletzko has been awarded the distinguished honor of being named a Most Valuable Professional (Visual Developer - Visual Basic) for 2006 by Microsoft!
"As a recipient of this year's Most Valuable Professional award, Scott joins an elite group of individuals in online and offline technical communities around the world who share their passion for Microsoft products and technologies with others. Microsoft® salutes all MVPs for promoting the spirit of community by helping other people realize their potential through technology."
| Click here to learn more about the MVP Program.Click here to read Scott's profile on the MVP site. |
VBCity Helper of the Month Winner
Saturday, July 1st, 2006
Scott Waletzko won the VBCity.com Helper of the Month contest for June 2006, and is now one of the VBCity.com Leaders!
Camelot BETA Completed
Sunday, May 28th, 2006
This weekend version 2 of the Camelot business management system has reached completion! Camelot is an extensible business management system that provides modular management capabilities to Echosoft Design Studio companies. Camelot is the first full system to be developed using Skystone Software's new and unique proprietary data modeling library, providing extended plug and play UI automation and data binding capabilities to developers, effectively eliminating well over 85% of user interface development time.
Camelot (and the underlying shared libraries) were written entirely in C# by Scott Waletzko, and use a SqlServer 2005 database for data storage. The Web-based portions of the system were written in ASP.NET / C# by Scott Waletzko.
Camelot and the Skystone Software data library are currently both designed to be used internally by Skystone developers.
2005 VBCity Community Member Award
Sunday, January 1st, 2006
Scott Waletzko has been honored by being named the 2005 VBCity Community Member of the Year. This award honours the member who has shown the best community spirit on the VBCity forums.
Tempest ALPHA Sealed
Saturday, October 15th, 2005
Today the first milestone in development of the Tempest Web Content Management system has been reached: we are putting a freeze on further ALPHA (v1) development, and full production development will begin in earnest. The site you are currently viewing is hosted using the ALPHA version of this product, developed to concept-test the unique XSL- and XML-based Web content management system built in .NET.
The production version of Tempest will be written entirely in C# (Version 1 was written in VB), and is expected to launch by January of 2007. Check back later for more information about Tempest.
VBCity .NET Fella Award
Monday, August 1st, 2005
Scott Waletzko has been awarded the distinguished honor of being named .NET Fella by the VBCity forum leaders for July of 2005!
"Each month the VBCity Leaders select a member who they think deserves recognition for their community spirit, attitude and technical knowledge in the .NET Forums. That member becomes the VBCity.NetFella."
Announcing Scott Waletzko's Blog
Scott's blog documents software development, architecture, and project management, and contains articles and documents written for online development forums.
