The 1.3.0.2918 build of CruiseControl.NET has an error in msbuild.xsl file which causes an XslLoadException to be thrown when trying to view the MSBuild output in the web dashboard. One of the users was nice enough to describe the changes to the file necessary to fix the problem. Unfortunately even the latest version of the file on the CruiseControl.NET Live site doesn't include the changes therefore I'm attaching the file to this post as convenience.

If you need cheap and simple OCR functionality Microsoft Office Document Imaging Type Library (MODI) is a nice option if its requirements (Microsoft Office 2003 or later) and limitations (limited language support) don't bother you. Here is a simple C# function that does OCR on the image with the specified path:

static string OCR(string path)
{
    MODI.Document doc = new MODI.Document();
    doc.Create(path);
    doc.OCR(MODI.MiLANGUAGES.miLANG_ENGLISH, false, false);
    string result = ((MODI.Image)doc.Images[0]).Layout.Text;
    System.Runtime.InteropServices.Marshal.ReleaseComObject(doc);
    return result;
}

However, there is another Microsoft Office object model related problem. For Office 2003 users to be able to use your application, the MODI 11.0 (2003 version) must be referenced in the project and the release version of the application must be compiled on a machine with Office 2003 installed. In such a case VB6 still managed to compile the project on a machine with a newer version of Office installed, since the newer version of the type library was automatically used (MODI 12.0 for Office 2007 in this case). On the other hand strong type checking at compile time prevents that in C#.

If you want to keep using Office 2007 and be able to compile such a project, the only solution is to install Microsoft Office Document Imaging as the only component of Office 2003 along the existing Office 2007 installation. Unfortunately this overwrites the Microsoft Office Document Image Writer printer driver from 2007 with the older version, therefore you'll have to start a lengthy process of repairing the Office 2007 installation afterwards. And don't forget to apply all the service packs and updates for Office 2003 before that since this will also overwrite the printer driver and you'll have to repair Office 2007 once again. I learned that the hard way.

In Windows Vista the default value for the Persist Security Info parameter of an ADO connection string has changed from True to False.

You should be aware of this because it can prevent your legacy code from working properly under Windows Vista. If its value is set to False the Server, Database, Trusted_Connection and Password parameters will be removed from the ConnectionString property of the Connection object once the connection has been opened. If you’re creating new connections by just copying the ConnectionString property from an existing and already opened connection to the new one, your code will break under Vista.

The problem can easily be fixed by explicitly setting Persist Security Info to True in your original connection string but it should be mentioned that this can be a potential security risk if untrusted code gets access to your Connection object. Even more so in case you’re not using integrated security and the connection string actually contains the user’s password for accessing the database. It’s a much better practice to have the actual connection string stored separately and use it directly to create new connections.

On a side note, SqlClient in ADO.NET works much more consistently. The Persist Security Info parameter always defaults to False. It also only removes the Password parameter from the ConnectionString property which makes changing its value to True completely unnecessary unless you really feel a strong urge to share your user’s password.

I used the Microsoft Self-Paced Training Kit as the study guide. In spite of the mistakes it contains (see errata) I still find it a useful overview of the topics covered by the exam. I even think of it as a great overview of .NET framework for every developer even if he’s not considering taking the exam. On the other hand it really shouldn’t be your only resource, more of a starting point to direct you to the topics you realize you don’t know enough about. MSDN or a more specialized book can help you from there on.

If you’re interested, I’m selling my own copy of the book at a reduced price. It is in mint condition, I’ve even left the 15% off voucher unused. On a side note: here you can always see the list of items I am selling. The link is listed among my other sites in the left column of this page.

I you haven't checked out our Vista site recently, now is the right time to do it. Since my last posting two new gadgets have been released:

• Slovenian Portfolio provides information from Ljubljana Stock Exchange and gives you the ability to track your personal portfolio.
• Slovenian Rates provides information on exchange rates from 4 Slovenian banks: Bank of Slovenia, NLB, SKB and NKBM.

We have just released our first Sidebar Gadget – Slovenian Radio.

The gadget features a centralized list of radio stations (retrieved from our server) and basic controls for selecting the station and adjusting the volume. Everything is packaged in a nice and simple GUI.

Try it out. It really is the most convenient way of listening to Slovenian radio stations online. You can download it for free here. Spread the word if you like it.

Since gadgets are HTML applications and the Windows Sidebar uses Internet Explorer 7 to render them, I prefer running their code directly in IE7 during development. It makes debugging easier and allows me to develop them in Windows XP on my primary development machine with all the tools properly setup.

While this works great in early development stages, it becomes a problem later on when you start using the Windows Sidebar object model (to implement settings, visibility changes handlers etc.). This specific code understandably can only be debugged while running in Windows Sidebar but the unfortunate side effect is that the calls to objects which don’t exist in IE7 break the scripts and effectively prevent running the would-be gadget in IE7 even without this functionality.

The following function can help you keep the gadget running directly in IE7 even after the gadget specific functionalities are already implemented:

function isGadget()
{
    try
    {
        var dummy = System;
        return true;
    }
    catch (err)
    {
        return false;
    }
}

Just check if the application is running in Windows Sidebar at gadget startup and make sure to use the object model only when this is true. You can also add alternative initialization for running directly in IE7 to provide default values for settings and any other gadget specific variables. By doing this you can still test new features directly in IE7 if they are not gadget specific.

The whitepaper sample code doesn’t exactly follow the guidelines for web development therefore I wrote my own sample with clearly separated HTML structure, CSS styles and JavaScript code. I decided to make it publicly available in case anyone else finds it useful. A few things are worth mentioning.

• Empty XHTML tags. For some reason the XHTML style empty tags don’t work as expected when they are filled from JavaScript code. It seems as if the engine would parse them as opened tags without the corresponding closing tag. Therefore you should always use the long form <span id=”mySpan”></span> instead of the short one <span id=”mySpan” />. This problem seems to be specific for gadgets. The same code runs just fine in IE7.
• Localization. I haven’t managed to get the localization to work at all. I suppose the engine uses the files from the locale directory corresponding to the current display language not the locale settings. This does make sense but with only English language available in Vista there’s no way to check that the current file organization in my sample gadget is really ok. I kept it in the sample since I’m pretty convinced that it is.
• Deployment. If you double click a file with a .gadget extension in Vista, you will automatically start the gadget installation process. The file needs to be a zip or cab archive containing the actual gadget directory structure. Vista behaves as if an application setup was started. This means that you should sign the file to increase the end user trust. You can use the Sign Tool to do that but in this case you need to make a cab file since zip files can’t be signed with it. I tried to make the cab file using a CAB Project template in Visual Studio 2005 but I couldn’t make the correct directory structure. I ended up using Cabarc. After all, I only had to run the following line in the gadget directory to build the cab file correctly.
  cabarc –p –r N ..\HelloWorld.gadget *

This whitepaper should definitely be your first source of information when starting with gadget development. Unfortunately I didn’t find it as helpful as it could be. Find below a few issues that could be covered better since I’ve been struggling with them for some time before I get everything to work as expected.

• The style definition for body in both pages is missing the unit – px. Without it the definition is invalid and the gadget shows up with minimum size. The correct style definition would be in the likes of:
  body
  {
     width: 130px;
     height: 50px;
  }
• The settingsUI property is a member of System.Gadget not System.Gadget.Settings. This time the error is in the reference not the whitepaper.
• If you’re only replacing the files in the C:\Users\<username>\AppData\Local\Microsoft\Windows Sidebar\Gadgets directory to update the gadget you might have some problems with caching even if you close all gadget instances as the whitepaper suggests. In my case the old image files and gadget.xml file were still used although they have been replaced. Restarting Windows Sidebar should help.
• Don’t forget that gadget settings are stored with a particular gadget instance. This makes it possible to display two instances of the gadget with different settings. The side effect is that they get lost every time you remove the gadget from the sidebar and put it back on. It works like that by design and if you need persistent common settings for all instances you’ll have to use a different solution.

I though I’d gather in one place all the useful links I found with information on development of Windows Sidebar gadgets.

• Gadget Development Overview whitepaper should be you first stop. It’s a short article explaining the basics of gadget development.
• Windows Sidebar Reference is the only documentation that is currently available. It’s not very detailed, neither always accurate but it should still serve you well.
• Gadget Corner is a blog maintained by the Windows Sidebar team. It contains a few articles with information that can’t be found anywhere else.
• Sidebar Gadgets Forum is the only forum dedicated to gadget development. On top of that the Windows Sidebar team members have the habit of answering the posted questions.