Last couple of weeks I have been coding a lot of Flex, specifically ScheduleViewer component included in flexlib version 1.9. I was mostly happy with ScheduleViewer component but I did have some minor annoyances. Actually, it was more curiosity than need that drove me to investigate the possibility of creating a custom entry renderer for ScheduleViewer component. As it turns out, it was very easy. Investigating the source code of the library, I noticed the component AbstracSolidScheduleEntryRenderer. This component was responsible for simple entry rendering, which I wanted to modify. Specifically, I wanted to modify the content of each schedule entry i.e. the date object was simply formatted as time rather than a date. Because of the fact that my schedule was really date related (rather than time related), I needed a renderer that would meet my needs. Let's look at the code of MyEntryRenderer.mxml:

<?xml version="1.0" encoding="utf-8"?>
<renderers:AbstractSolidScheduleEntryRenderer 
    xmlns:mx="<a href="http://www.adobe.com/2006/mxml">http://www.adobe.com/2006/mxml</a>" 
    xmlns:renderers="flexlib.scheduling.scheduleClasses.renderers.*" 
    paddingTop="0" 
    paddingLeft="0">
        
    <mx:Script>
        <![CDATA[
            import mx.formatters.DateFormatter;
            import flexlib.scheduling.scheduleClasses.IScheduleEntry;
            
            private var formatter:DateFormatter;
            
            override public function onPreinitialize() : void
            {
                formatter = new DateFormatter();
                formatter.formatString = "MM/DD";
            }
            
            override public function set data ( value : Object ) : void
            {
                super.data = value;
                
                entry = value as IScheduleEntry;
                var content : SimpleScheduleEntry = SimpleScheduleEntry( entry );
                
                drawTextContent(content);
            }
            
            protected function drawTextContent(content : SimpleScheduleEntry) : void
            {   
                formatter.error = "";
                
                var time : String = formatter.format( content.startDate ) 
                 + " - " + formatter.format( content.endDate );
                
                toolTip = time + "\n" + content.label;
                contentLabel.text = time;
                contentLabel.styleName = getStyle( "timeStyleName" );
                contentText.text = content.label;       
            }
        ]]>
    </mx:Script>
    
    <mx:Label id="contentLabel" />
    <mx:Text id="contentText" />
    
</renderers:AbstractSolidScheduleEntryRenderer>

From the code above it is clear that we are simply customizing existing component to meet our needs. Similar to any custom components in Flex, we are simply modifying the content of an existing component by using DateFormatter object. The function DrawTextContent is responsible to set the content of the text box and a label found on AbstractSolidScheduleEntryRenderer. This function is called by setter function of the data member of the AbstractSolidScheduleEntryRenderer, which is called by ScheduleViewer component during the drawing phase. Once the customization is performed, we simply have to specify that we want to use the new renderer in following way:

<ns1:ScheduleViewer
    id="MyScheduleViewer" 
    width="800" 
    height="100%"
    rowHeight="25"
    startDate="{ StartDate }"
    endDate="{ EndDate }"
    verticalGridLineAlpha=".1"
    horizontalGridLineAlpha=".1"
    entryRenderer="MyEntryRenderer"
    entryLayout="flexlib.scheduling.scheduleClasses.layout.SimpleLayout"
    color="#FFFFFF"
    borderColor="#FFFFFF" 
    themeColor="#FFFFFF" 
    backgroundColor="#FFFFFF" 
    click="OnScheduleClick(event)" />

As we can see from the code above, all we needed to do is set entryRenderer property to be our newly defined component. One thing to note is that we do have to set entryLayout property to be "…layout.SimpleLayout", because only then the rendering is performed using AbstractSolidScheduleEntryRenderer. At this point the customization is finished.

Unlike Silverlight, Flex Builder does not integrate with Visual Studio programming environment. Therefore, debugging ASP.NET or Flex applications can become very cumbersome, especially when they become very large. However, with Flex Builder 3, Adobe has made possible to utilize built in ASP.NET web server (Cassini) to debug Flex applications. Following post describes one possible way to set up both environments to make debugging easier.

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Lately, Adobe Flex has been getting more and more attention in programming community. Especially after the launch of open source version of Flex SDK developers are able to make rich Internet applications (RIA) using Flex, which (as everybody knows) produces a flash file (swf) that can be used in any web application. The article will focus on the following topics:

1. Communication between Action Script (HTTPService) and .NET (HTTP Handler);
2. Security - securing HTTP Handler calls from unauthorized access;
3. ASP.NET Forms Authentication and Authorization through Flex;
4. ASP.NET Handlers and session management;

It is assumed that the reader is familiar with basic concepts of ASP.NET handlers, forms authentication, and Adobe's Action Script.
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SQL Server 2005 has been released for a while now, and most of the new features are well known throughout programming community. Right after the initial release, I downloaded a copy of SQL Server 2005 Express, eager to explore new features. At first, there was a lot of reading and browsing the documentation; then I moved onto converting smaller projects to SQL Server 2005 edition, and finally I decided to move larger projects to my new favorite DBMS. Throughout conversion process, I was poised to utilize the newest feature of SQL Server 2005: CLR Stored Procedures.
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There are many challenges surrounding database development. With the project size, the development becomes more complicated and harder to maintain. One specific issue is the question of going about writing SQL script so that the maintenance and/or updates are handled properly. I was always found of "divide and conquer" technique, which I religiously follow during each and every project. In case of database development, I try to divide my script into multiple atomic entities, which I can execute independently or combined. The advantage: Updates/modifications are handled as independent as possible, affecting only necessary part of the project.
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Multiple Document Interface (MDI) is a technique to separate data layer from presentation layer, which is primarily utilized in MFC. As an MFC developer looking to develop applications in .NET, I was searching for a similar concept. My interest was mostly in GUI design, rather than complete MDI/SDI solution. At first, I was very happy to learn that Windows Forms provided assistance in MDI development. As always, I fired up VS.NET 2005 and created sample project. Couple of minutes later, I had MDI-like application, where I could add/remove views very quickly. It felt too good to be true, which later proved that it was. At first I wanted all of my child views to be shown maximized. In addition, I wanted all child views without a control bar. Everything went well, except that my forms could not get rid of control bar. In addition, form resizing did not function properly. As always, I searched the web and found numerous attempts to solve these issues. All solutions suggested following steps:
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In my previous post Displaying .NET DataSet with Crystal Reports I discussed one way to report the data that does not come directly from a database. In this way, it is possible to preform more complex data analysis and present the result using Crystal Report engine. Following post addresses similar issue. However, here, the data to be presented is not stored in a DataSet, but rather in a .NET Collection, which implements IEnumerable interface.
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Couple of days ago, I started playing with Crystal Reports engine included with Visual Studio.NET. After creating several reports using SQL Express database, I started wondering how to create reports that require more sophisticated data analysis. At first, my thoughts were to utilize stored procedures to create report result, and and then display the result using Crystal Report engine. However, it turned out that Crystal Report engine has some limitations when it comes down to stored procedures. Crystal Reports documentation states that stored procedures can be utilized if they contain at most one SQL SELECT statement. In addition, the documentation states that no return parameters can be utilized (parameters declared by SQL keyword OUT, or INOUT). Clearly, complicated data analysis cannot be performed using single SELECT statement. Considering these limitations, I immediately started to investigate options to present a structure using Crystal Reports. At first, I considered a .NET containers, but Crystal Reports engine did not seem to provide any convenient way of displaying such structures. In addition, I noticed that every report that I designed, required the structure of the data to be known at report design time. At that time, two options came to my mind:
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Couple of days ago, I installed BlogEngine.NET on my home server's root directory. Besides being extremely impressed by BlogEngine.NET, I noticed that all of my other sub-applications started crashing. Immediately, I knew that the installation of BlogEngine.NET affected all other web applications. After short investigation, I noticed that all of my sub-applications were trying to load handlers and modules defined in BlogEngine class library. Specifically, all web applications tried to load following:

[...]
<httpModules>
      <add name="WwwSubDomainModule" type="BlogEngine.Core.Web.HttpModules.WwwSubDomainModule, BlogEngine.Core"/>
      <add name="UrlRewrite" type="BlogEngine.Core.Web.HttpModules.UrlRewrite, BlogEngine.Core"/>
      <add name="CompressionModule" type="BlogEngine.Core.Web.HttpModules.CompressionModule, BlogEngine.Core"/>
      <add name="ReferrerModule" type="BlogEngine.Core.Web.HttpModules.ReferrerModule, BlogEngine.Core"/>
      <!--The CleanPageModule below removes whitespace which makes the page load faster in IE. Enable at own risk -->
      <!--<add name="CleanPageModule" type="BlogEngine.Core.Web.HttpModules.CleanPageModule, BlogEngine.Core"/>-->
      
      <!--Remove the default ASP.NET modules we don't need--> 
      <remove name="PassportAuthentication" />
      <remove name="Profile" />
      <remove name="AnonymousIdentification" />
    </httpModules> 


    <httpHandlers>
      <add verb="*" path="file.axd" type="BlogEngine.Core.Web.HttpHandlers.FileHandler, BlogEngine.Core" validate="false"/>
      <add verb="*" path="image.axd" type="BlogEngine.Core.Web.HttpHandlers.ImageHandler, BlogEngine.Core" validate="false"/>
      <add verb="*" path="syndication.axd" type="BlogEngine.Core.Web.HttpHandlers.SyndicationHandler, BlogEngine.Core" validate="false"/>
      <add verb="*" path="sitemap.axd" type="BlogEngine.Core.Web.HttpHandlers.SiteMap, BlogEngine.Core" validate="false"/>
      <add verb="*" path="trackback.axd" type="BlogEngine.Core.Web.HttpHandlers.TrackbackHandler, BlogEngine.Core" validate="false"/>
      <add verb="*" path="pingback.axd" type="BlogEngine.Core.Web.HttpHandlers.PingbackHandler, BlogEngine.Core" validate="false"/>
      <add verb="*" path="opensearch.axd" type="BlogEngine.Core.Web.HttpHandlers.OpenSearchHandler, BlogEngine.Core" validate="false"/>
      <add verb="*" path="metaweblog.axd" type="BlogEngine.Core.API.MetaWeblog.MetaWeblogHandler, BlogEngine.Core" validate="false"/>
      <add verb="*" path="rsd.axd" type="BlogEngine.Core.Web.HttpHandlers.RsdHandler, BlogEngine.Core" validate="false"/>
      <add verb="*" path="css.axd" type="BlogEngine.Core.Web.HttpHandlers.CssHandler, BlogEngine.Core" validate="false"/>
      <add verb="*" path="js.axd" type="BlogEngine.Core.Web.HttpHandlers.JavaScriptHandler, BlogEngine.Core" validate="false"/>
      <add verb="*" path="rating.axd" type="BlogEngine.Core.Web.HttpHandlers.RatingHandler, BlogEngine.Core" validate="false"/>
      <add verb="*" path="opml.axd" type="BlogEngine.Core.Web.HttpHandlers.OpmlHandler, BlogEngine.Core" validate="false"/>
      <add verb="*" path="monster.axd" type="BlogEngine.Core.Web.HttpHandlers.MonsterHandler, BlogEngine.Core" validate="false"/>
      <add verb="*" path="blogml.axd" type="BlogEngine.Core.Web.HttpHandlers.BlogMLExportHandler, BlogEngine.Core" validate="false"/>
</httpHandlers>
[...]

At first, I was very confused that all sub-applications are loading web.config from the root application. I thought that each web application simply used the web.config from it's own virtual folder (besides machine.config). To investigate the issue, I started searching the web and after a short time I found the following article. The article explains the way IIS 6 is handling web configuration loading and inheritance. Frustrated with the result, I was determined to find solution to my problem. And then it hit me: <location> tag! With <location> tag, it is not only possible to control application security, but also selectively load parts of web.config. Actually, the accurate statement would be that <location> option allows user to control if "child" applications will inherit portions of web.config. In this way, I was able to pick and choose, which parts of web.config will be loaded in sub-applications. Following part of web.config explains everything:

[...]
<location inheritInChildApplications="false">
 
  <system.web>
    
  [...]   
 
  </system.web>
  
</location>
[...]

Adding <location> option solved my headache ...

Couple of weeks ago, I needed to parse a set of XML files. As always, my first thought was to search the web for free XML parsers. But then I remembered that I found a solution in the past: Xerces XML parser. Even though, xerces was originally written in Java, there is an excellent port to c/c++. Xerces was developed by Apachi Software Foundation, and it supports wide range of compilers. To use it with Visual Studio 2005 C++ compiler, following steps are required:

1. Download compiler in binary form from here;
2. Unpack into any folder; This step will create subfolders include and lib;
   
3. Add path include and lib folders to VC++ directories;
4. To statically link to a project, link with xerces-c_static_2.lib or (xerces-c_static_2D.lib for debug version);
5. Set to ignore libcmt.lib

Steps 4 and 5 are shown in the screen shot below: