Deepak Sharma's Blog

Understanding XML Schema

There's a new article on MSDN by Aaron Skonnard on how to use XML Schema definition language.

XML Schema is poised to play a central role in the future of XML processing, especially in Web services where it serves as one of the fundamental pillars that higher levels of abstraction are built upon. This article describes how to use the XML Schema definition language in more detail.

Good Read.

Sam Gentile on IIS 6.0 on Microsoft Windows Server 2003

Sam wrote about New Request Processing Architecture of IIS 6.0 on Win2K3. IIS now consists of two kind of processes, Kernel-mode and user-mode (and then there are Worker processes). Read about the new architecure and more in Sam's article. Truly a next generation stuff in terms of Reliability and Scalability. Good read.

There is also an article on Microsoft Windows Server website which provides a very good technical overview of IIS 6.0

WS-* still going strong

Microsoft Corp., IBM Corp., BEA Systems Inc. and TIBCO Software Inc. have released two new specifications, WS-ReliableMessaging and WS-Addressing. I wonder where this leaves Don Box's statement about Enough of Specs.

Feeling Good

devCity.Net published my first .Net article. This is the first time I'm getting something published out of my website. Feeling great. I wonder how it must feel when you author a book. The article (it's a tip actually) is about Enumerating IP Addresses of a Local Machine Using VB.NET.

Also, I have been busy last few weeks reviewing some really cool books (all good stuff) on .Net and other subjects to be published by Addison Wesley Professional. Can't elaborate further on that because of the NDA.

Enough of Specs, Courtesy: Don Box - I don't agree.

"Specs are like bodily orifices: Everybody has them and they all have certain unique characteristics. But just writing a spec means nothing. If you write a spec that no one implements, did it ever really specify anything?"

These are the words of Don Box @ XML Web Services One conference 2003. But is he or Microsoft following this advice. Roll back to Aug 2002 when Don Box said something very similar at the XML Web Services One conference (same conf). Notable are these lines from his presentation.

Box said XML Web services are a means to an end. "We have to get the plumbing sorted out," he said. "We have a couple more years of plumbing work, but after that we move on to applications," he said. Box said the "protocol work is starting to wind down, the infrastructure is catching up with protocols and it's time to start thinking about applications."

So why these statements suddenly. Since Aug 2002, Microsoft has released atleast six WS-* Specifications and I am sure these are not over yet. Does MS feel that they have covered all the areas of web services. Rest assured, coming months we will see more and more of these from MS and others.

Don also has few tips for us guys.

His four tips for developers: Read fewer specifications, write more applications, write less code by using tools that generate code automatically, and remember that humans matter, so if you must write a specification, make it legible.

I agree with all except for the first one. I know it's kind of getting difficult to catch up with all the specifications, but reading fewer specs will restrain your choices. On the other hand, if you don't write applications based on these specs, the specs don't "specify anything". I have mixed feelings reading this article.

Essential .NET is not for the faint-of-heart

I have been reading lots of blog posts about Don Box's book. I agree with Sam and Scott, that this book is not for the people who are just getting started with .Net and certainly not for the people Sam describes in this great essay. In my opinion, this book sits along with Jefferey Richter's Applied Microsoft .NET Framework Programming book. BTW, I derived the title of this post from this review of the Essential .Net book. Check it out, much better than some other reviews.

Quick and Dirty RSS Reader

OK, So I have been reading about a lot of RSS Aggregators and I thought why not give it a try myself . So here is a very quick and dirty RSS reader (Can't call it aggregator though). Nothing special here, just some basic System.Net and XML classes and XSL transformation (I used eXcelon Stylus Studio to generate XSL). Here's the ASPX code:

<%@ Page language="VB"  %>
<%@ Import Namespace="System.Net" %>
<%@ Import Namespace="System.IO" %>
<%@ Import Namespace="System.Xml" %>

<script runat="server">

Sub Page_Load (sender As Object, e As EventArgs)

 retrieveXML.Document = retrieveRSS()

End Sub

Function retrieveRSS()

Dim request as WebRequest = request.create("http://dotnetweblogs.com/dsharma/Rss.aspx")

'Get the Web Response Object from the request
Dim response as WebResponse = request.GetResponse()

'Get the Stream Object from the response
Dim responseStream as Stream = response.GetResponseStream()

Dim reader as XmlTextReader = new XmlTextReader(responseStream)

Dim xml_doc as XmlDocument = new XmlDocument()

'Load the RSS document
xml_doc.Load(reader)

retrieveRSS = xml_doc

End Function
</script>

<html>
<title>RSS Reader</title>
<body>
<asp:Xml id="retrieveXML" TransformSource="new.xsl" runat="server" />
</body>
</html>

Here's the XSL:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="xml" omit-xml-declaration="yes"/>

<xsl:template match="*">
   <table cellSpacing="0" width="100%" border="1" cellPadding="5">
    <tr>
     <td bgColor="#6495ed" width="100%">
      <a><xsl:attribute name="href">
       <xsl:value-of select="channel/link"/>
      </xsl:attribute>
       <strong>
        <font face="Trebuchet MS" color="#ffffff">
         <xsl:value-of select="channel/title"/>
        </font>
       </strong>
      </a>
      <br/>
      <strong>
       <font face="Trebuchet MS" color="#ffffff">
        <xsl:value-of select="channel/description"/>
       </font>
      </strong>
     </td>
    </tr>
    <tr>
     <td width="100%">
      <xsl:for-each select="channel/item">
       <font face="Trebuchet MS">
        <font size="2">
         <b><xsl:value-of select="title"/></b><xsl:text disable-output-escaping="yes"> (Posted on: </xsl:text><xsl:value-of select="pubDate"/> <xsl:text>)</xsl:text>
         <br/>
         <br/>
         <xsl:value-of select="description" disable-output-escaping="yes"/>
         <br/>
         <br/>
        </font>
       </font>
      </xsl:for-each>
     </td>
    </tr>
   </table>
</xsl:template>

</xsl:stylesheet>

Above code colorization provided courtesy of Mark it Up.

Web Services authentication using WSE

XML for ASP.NET Developers website has a video tutorial on how to use the newly released Microsoft's Web Service Enhancements (WSE) classes to authenticate the Web Service callers. Check it out.