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Lynx Welcome!

Just going through various stats on my blog today and noticed that last month, there were 57 visits to this site using Lynx.

Lynx?

Are you serious?

Does looking at this site via Lynx make my ass look big?

Lynx, for the unitiated, is a text based browser designed to allow mainframes to present a browsing tool to its users. It is the first web browser I ever used back in college. You ain’t ever navigated the web till you’ve done it in a text browser.

So to you Lynx users, I should mention that we now have these newfangled 32-bit processors that are capable of running browsers that can render and format text and images. They’re really a hoot!

All kidding aside, my understanding is that people still use Lynx for accessibility reasons. For example, blind people can have the site read to them with a Stephen Hawking like voice. That’s pretty sweet.

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Map of Spain The missus and I are pretty much packed and ready to go. We have to be at the airport at 5 AM. Yes, that is AM as in early morning (or late at night depending how you look at it).

I doubt we’ll get much real solid sleep, so I probably won’t even try too hard. Besides, I am at that point before any trip where my mind is racing trying to figure out that one thing I forgot to pack. And there is always that one thing. As I step on the pain, it will suddenly spring forth into consciousness and I will curse myself for forgetting it. Whatever it may be.

Also, I am NOT bringing my computer. I am detaching from this here intarweb (though I will bring my iPod). So this blog will go radio silent for nine days unless we have spare time and happen to be in an internet cafe. I might login to delete comment spam.

P.S. While I’m gone, be sure to read some of my latest posts and let me know what you think.

**

If you start to miss me, just click on February 2004 to the right and start from the beginning as if I never left. ;)

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The Framework Design Guidelines has an illuminating discussion on the Dispose pattern for implementing IDisposable in chapter 9 section 3. However, there was one place where I found a potential problem.

But first, without rehashing the whole pattern, let me give a brief description. The basic Dispose Pattern makes use of a template method approach. I really like how they take this approach. Let me demonstrate…

public class DisposableObject : IDisposable
{
    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }

    //This is the template method...
    protected virtual void Dispose(bool disposing)
    {
        if(disposing)
        {
            Console.WriteLine("Releasing Managed Resources in base class!");
        }
    }
}

This disposable class implements a non-virtual Dispose method that calls a protected virtual method. According to the guidelines, classes that inherit from this class should simply override the Dispose(bool); method like so.

public class SubDisposable : DisposableObject
{
    protected override void Dispose(bool disposing)
    {
        Console.WriteLine("Releasing Managed Resources in Sub Class.");
    }
}

Notice anything odd about this? Shouldn’t this inheriting class call base.Dispose(disposing)? The guidelines make no mention of calling the base dispose method. However, just to make sure I wasn’t missing something, I ran the following code.

using(SubDisposable obj = new SubDisposable())
{
    Console.WriteLine(obj.ToString());
}

This produces the following output:

UnitTests.Velocit.Threading.SubDisposableReleasing Managed Resources in Sub Class.

Notice that resources in the base class are never released.

Also, while I applaud the use of a protected template method to implement the dispose pattern, I think it is possible to take the pattern one step further. The purpose of using template methods is bake in an algorithm consisting of a series of steps. You provide abstract or virtual methods to allow implementations to change the behavior of those distinct steps.

When I think of the steps it takes to dispose an object using the simple pattern, it consists of the following discrete step:

  • Calling Dispose indicates object is being disposed and not being finalized
  • Call into protected Dispose(bool);
  • Protected method releases unmanaged resources
  • if disposing
    • release unmanaged resources
    • Suppress finalization

So why not codify these series of steps into the pattern. The Simple Dispose pattern might look like…

public class DisposableObject : IDisposable
{
    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }

    void Dispose(bool disposing)
    {
        ReleaseUnmanagedResources();
        if(disposing)
        {
            ReleaseManagedResources();
        }
    }

    //Template method
    protected virtual void ReleaseUnmanagedResources()
    {}

    //Template method
    protected virtual void ReleaseManagedResources()
    {}
}

Notice that the Dispose(bool); method is now private. There are two new virtual template methods. Also note these are virtual. I did not make these abstract, since this gives the inheritor a choice on whether to implement them or not. This might seem like overkill, but it removes one more decision to be made when overriding this class. That is the goal of these patterns, to make doing the right thing automatic to the implementer.

In the previous pattern, an implementer has to remember what to do when disposing is true as opposed to it being false. Do I release unmanaged when its true? Or when its false. Certainly if you’re implementing the pattern, you should really know this down pat. But still it doesn’ hurt to make the algorithm more readable. Looking at this modified pattern, it is quite obvious what I need to do in the method ReleaseManagedResources. I probably need to add documentation to tell the overriding implementer to make sure to call base.ReleaseManagedResources().

The only open question I have with this pattern is whether or not it is safe to call base.ReleaseUnmanagedResources() from an implementing class. I need to dig into the C# specs to understand that issue fully. The issue is that from within ReleaseUnmanagedResources, you really shouldn’t touch any managed resources, because this method could be called from a finalizer thread. Is calling a method on your base class in violation of this rule?

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As soon as I saw the code sample on K. Scott Allen’s latest blog post, I knew he was talking about the Membership Provider.

His example nails it when describing the complexities of defining a contract via an interface. It just isn’t expressive enough. Documentation is always necessary.

I ran into this recently when trying to implement a custom Membership Provider for DotNetNuke. It turns out that DotNetNuke maintains its own user and role tables. These “satellite” tables map to the ASP.NET membership tables (but do not have any foreign key constraints) since they provide more information specific to DotNetNuke.

So how do the satellite DNN tables stay in synch with your provider data store? Well when you login and DNN doesn’t have a record of the current user, DNN will call into your provider to get a list of users and then it iterates through each one adding the user to its own user tables if the user doesn’t already exist.

I couldn’t even get the roles to synchronize properly, but I didn’t spend enough time. What I discovered is that following the Membership Provider contract wasn’t enough. I actually needed to know what the consumer was doing with my provider to understand why it would take so long to login a user.

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One complaint that I’ve had about DotNetNuke (DNN for short) is the difficulty I’ve had in creating skins that match client design comps exactly to the pixel. And believe me, they check every single one.

One key issue is how container skins work. Every module (analagous to a web part) in DNN is wrapped by a container skin. This is an ascx control that can be used to apply a border and title around a module should you so wish.

However, the most important part of a container control is that it contains placeholders for action controls, controls that present options to user who has rights to edit the module. Options might include editing the content of the module, changing its settings, or moving it to another content pane on the page.

The examples below present a Semantic Link Module I wrote (it uses an unordered list instead of a table to render the link list) while in normal content mode and while logged in as an administrator.

\ Figure 1: Normal View

\ Figure 2: Editable View

The container that wraps this module has to have a placeholder for the little pencil edit links. The general structure for default container ascx files that ship with DNN looks like the following.

< table cellpadding =”0” cellspacing =”0” border =”0”>

    < tr >

        < td >< dnn:Actions runat =”server” id =”dnnActions” /></ td >

        < td ><! – Maybe another DNN control //– ></ td >

    </ tr >

    < tr >

        < td colspan =”2” id =”ContentPane” runat =”server”>

            <! – Your dynamic content is placed here – >

        </ td >

    </ tr >

</ table >

Notice that the Actions control is in its own table row. Ideally when you are in the normal view, that row would collapse to nothing. Unfortunately, not all browsers are so kind. IE for example will leave a one pixel gap. Ideally, you would like to mark that row in such a way that it isn’t even rendered to the client.

That’s where my new ContainerOptions control comes into play. It is a very simple custom control used to wrap container options such that they completely removed in the normal view, getting rid of that one pixel gap. See the following snippet for an example of the usage.

< table >

    < vdn:ContainerOptions runat =”server” id =”Containeroptions”>

        < tr >< td >< dnn:Actions runat =”server” id =”actions” /><! – … – ></ td ></ tr >

    </ vdn:ContainerOptions >

    < tr >

        < td id =”ContentContainer” runat =”server”></ td >

    </ tr >

</ table >

This control inherits from the System.Web.UI.WebControls.PlaceHolder control and simply sets its visibility to false unless the module in the container skin is editable by the current user.

The way it figures this out is it walks up the control hierarchy till it finds the DotNetNuke.UI.Containers.Container control that contains it. From there it can access the module contained by the container and check the module’s IsEditable property.

Since I pretty much only deal with creating skins using ascx controls, I did not go to the extra trouble to apply this technique to a skin object. It is simply a custom control.

The source for this is very small and can be downloaded here.

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I am now a published DevSource article author. :)

Well actually, Bob Reselman (aka Mr. Coding Slave) did nearly all of the writing. I merely provided technical editing and proofing along with clarifying some sections. In return, he graciously gave me a byline.

The article is a beginners guide to exceptions.NET. and Bob did a bang-up job especially given the circumstances. He writes in a very approachable manner.

Hopefully, we can follow-up with a more in-depth version to take beginners to the next level in understanding best practices. One thing I wish we had discussed in the article is the guidelines around re-throwing exceptions. For example, I’ve seen many beginning developers make the following mistake…

public void SomeMethod()

{

    try

    {

        SomeOtherMethod(null);

    }

    catch(ArgumentNullException e)

    {

        //Code here to do something

 

        throw e; //Bad!

    }

The problem with this approach is the code in the catch clause is throwing the exception it caught. The runtime generates a stack trace from the point at which an exception is thrown. In this case, the stack trace will show the stack starting from the line throw e and not the line of code where the exception actually occurred.

If this is confusing, consider that the runtime doesn’t exactly distinguish between these three cases…

Exception exc = new Exception();

throw exc;

\

throw new Exception();

\

throw SomeExceptionBuilderFunction();

If you really intend to rethrow an exception without wrapping it in another exception, then the proper syntax is to use the throw keyword without specifying an exception. The original exception will propagate up with its stack trace intact.

public void SomeMethod()

{

    try

    {

        SomeOtherMethod(null);

    }

    catch(ArgumentNullException e)

    {

        //Code here to do something

 

        throw; //Better!

    }

However, even this can be improved on depending on why we are catching the exception in the first place. If we are performing cleanup code in the catch clause, it would be better to move that code to the finally block and not even catch the exception in the first place.

Also, using the throw syntax as illustrated above can affect the debuggability of a system. Christopher Blumme points this out in his annotation in the book Framework Design Guidelines (highly recommended) where he notes that attaching a debugger works by detecting exceptions that are left unhandled. If there is a series of catch and throw segments up the stack, the debugger might only attach to the last segment, far away from the actual point at which the exception occurred.

public void SomeMethod()

{

    try

    {

        SomeOtherMethod(null);

    }

    finally

    {

        CleanUp(); //Possibly even better

    }

}

Bob and I plan to follow-up with hopefully more articles covering exceptions. This is just a start.

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BoingBoing has this story on a guy who fixes computers in exchange for…er…special favors from female customers. First the plumber, and now the computer guy. This could start a whole new breed of dirty movies.

***Fade in cheesy 70s music with the bump-chi-ca-bumb-waaoow***\ ***Door rings***\ Housewife: (opens door) Who is it?\ IT Guy: I’m the IT guy. I’m here to fix your computer. (Follows up with cheesy line I refuse to print)\ ***Fornication ensues***

It’s a damn good thing I know how to fix computers around here. Now I just need to learn how to do the plumbing.

Yes, this is the first post that I feel I had to edit due to AdSense. The last thing I want to see are the ads that would be associated with this post should I have used the words porn and sex.

DOH!

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Rock Recently, two posts have given me an increased appreciation for what Flickr has accomplished with their clustering feature.

In his post Random Acts of Sensless Tagging, DonXML talks about the weakness of simple tagging schemes to understand the semantics of a tag. Today, Jeff Atwood follows up this thought by illustrating how a Google search for a single word also returns results that ignore other possible meanings of the word. He presents eBay as a better example with its “quasi-hierarchical” category results in the side bar.

Jeff even suggests a better approach using Markov chain probabilities to automatically suggest alternat semantics. For example, you search on “Jaguar” and in the search results you get a suggestion, “Did you mean: Jaguar cat, Jaquar Automobile, OSX Jaguar…”

Well this is exactly what Flickr does when searching for tags. Try searching for the tag “rock”. Flickr returns a set of clusters around the term. In the top cluster (at the time of this writing), there are pictures of bands music bands and guitarists. The other clusters involve stones, ocean, beaches as one might expect. The last one interestingly enough associates “rock” with “hard” and “cafe”.

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So in exactly one week Akumi and I will be on a plane to Spain where it rains in the plains (please excuse me). We are flying into Madrid in the morning of the 20^th^ where we’ll stay the night. There, we will meet up with Akumi’s brother and his wife who will have flown in from Japan a couple days earlier.

Madrid boasts such great sights as Museo del Prado, Palacio Real and Plaza Mayor, but the highlight for me will be to visit the place I lived for three years as a kid. I look forward to seeing how much it changed and if they ever cleaned up all the grafitti we the local hoodlums did (hey, this was the time when Breakin’, Electric Boogaloo and Beat Streat were out, what was a kid to do?).

I am almost certain the legend of my fútbol prowess in the Terraza Grande de los Apartamentos Torrejón will still be mentioned in hushed tones by the local kids who play there today. Assuming they can contain their laughter.

From Madrid, we are travelling to Léon for a day and a half, and then Bilbao for a day and a half. Then we are on a late train to the Catalan city of Barcelona for four days. No offense to my amigos Madrileños, but I am really looking forward to beautiful Barcelona. The first time I visited, I have hazy memories of its beauty. This time I hope to soak it in more.

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I would like to take this moment to point out that as far as I know (and the judges are still confirming this), I may have made history with my last blog post as the first geek blogger in history to mention Breakin’, Electric Boogaloo and Beat Streat all in the same blog post with proper IMDB linkage.

For you young whippersnappers who missed out on this fine piece of cinema history, you are in luck. Amazon.com offers up its Breakin’ Collection which packages all three of these movies. Perhaps the only movie missing is Krush Groove (which I admit, I never saw).

This is one chapter in the history of hip-hop and breakdance. Learn your roots, foo!

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Chicken An IM conversation I had with a teammate on a project today…

haacked: Hey, let’s just switch the whole proj to VS.NET 2005 while I’m fixing things.\ Teammate: i can’t tell if you’re kidding or not\ haacked: kidding.\ haacked: sort of.\ Teammate: yeah… we should be brave… but maybe a little later\ haacked: what? Are you chicken? BWOK! BWOK! BWOK! (emphasis added… editor)\ Teammate: i ain’t chicken!\ haacked: <!– (Because that’s so effective a motivator)\ Teammate: dude, i’ll recompile in .Net 2.0 and deploy to production right now!\ haacked: I DARE You! Do it man! Do it!\ Teammate: well, i would but i don’t have 2005 installed on this machine… but otherwise, i would totally do it\ Teammate: man if i had 2005 installed, you’d be so moded\

Notice that after all these years, the power of the BWOK BWOK still has its sway. It’s the real reason that lemmings jump off of cliffs. It isn’t because the other lemmings do it. It’s because one brash lemming challenged the others by calling them chicken and making the BWOK BWOK sound. Perhaps said lemming even flapped his furry little arms in a chicken imitation. That seems to really get people’s…er…feathers ruffled.

Oh, and if you are a current or potential client, I would never simply deploy a new platform mid-project like that. But this other guy might. ;)

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Wired News has a very interesting article on History’s worst software flaws.

It makes me think of my worst software bug when I first started off as an ASP developer right out of college. I was working on a large music community website and was told to implement a “Forgot Password” feature. Sounds easy enough. I coded it, ran a quick test, and then deployed it (that alone should rankle your feathers).

We didn’t quite have a formal deployment process at the time. A few days later, we find out that the code never sent out any emails, and never logged who made the requests, leaving us no way to really know how many users were affected.

I believe we found out (and my memory is hazy here), through a relative of our client’s president. After reviewing the code, there was no way it could have sent out emails. There was a glaring bug in there, which makes me wonder how it passed my test.

In any case, I coded on egg shells for a while after that, fearing I might lose my first coding job.

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Ingo Rammer writes about the theoretical limit to reducing latency. Since 1994, we’ve reduced latency by 10 times, but increased bandwidth by millions. We can make the pipes fatter, but we can’t make the data any faster than the speed of light unless, as Ingo points out, “you prove Einstein wrong”.

According to Einstein’s special theory of relativity, the speed of light is an absolute barrier. Not only is the speed of light itself limited, but anything that communicates information is also bound by that limit.

The reason for this is that the speed of light is the same in all frames of references. Suppose I’m in a train heading east from California to New York at half the speed of light and I pull out a flashlight (maybe it is dark in there). I face the flashlight toward the front of the train (say it is 100 meters away) and turn it on. The beam of light from my frame of reference appears to head east at 186,282.4 miles per second which is denoted by the constant c (as in the c in E=mc^2^) and reaches the front of the train in a split second.

Now suppose somebody in Nebraska happens to be sitting outside watching the trains go by and sees me turn on the flashlight. From his perspective, the beam of light travels west to east at exactly the same speed c. Interestingly enough though, during that same split second, the beam of light travels farther before it reaches the front of the train, because the train itself is moving. How is it possible that light, travelling at the same speed, travels two different distances in the same amount of time?

It doesn’t. The elapsed time itself is different from our two perspectives. This is the paradoxical (but experimentally verified) phenomena called time dilation.

So what does this have to do with latency? The perceived time dilation is the ratio between an external observer’s perceived time and the time perceived by an observer approaching the speed of light. As the the latter observer gets closer to the speed of light, the ratio approaches zero. This would violate causality. If we could send a ping faster than light, from one frame of reference an obsever would observe that the ping was sent before it was received (as expected by causality), but in another frame of reference, the observer would observe the ping as being sent after it was received.

So is it possible to prove Einstein wrong? Perhaps, but not likely. Time dilation has been experimentally verified. There is promise in Quantum Entanglement, but so far it seems impossible to to transmit information using this approach. There are a class of theoretical particles (non have been observed) that might be faster than light, but these would also run into c as a barrier. In this theory, the speed of light is impossibly slow. Good luck trying to rope one of them in to send your ping packet. Those particles are most likely travelling backwards in time, thus not violating causality. They just exhibit causality in a different direction.

If anything will prove Einstein wrong (and I am skeptical) is discovering that causality itself is not sancrosanct. Perhaps time itself is an illusion.

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The title of my post is meant to indicate that this post is not technical in nature, but rather just a bit of small talk, chit-chat, idle conversation. You know, the sort of surface level conversation meant to break the ice and pass the time. How is the weather where you are?

The weather where my parents and brother live is rather cold right now. Today’s high was 20° F with a low of 8° F (that’s -6.7° C and -13° C respectively). Tomorrow they will enjoy a brisk 12° F high and 2° F low (which is -11° C and -16° C). Brrrr!

That’s why we’re looking forward to having them thaw out by visiting us in December. Right now we’re enjoying a nice high of 75° F and a low of 56° (egads! Time to bust out a sweater!).

Meanwhile, we are excitedly looking forward to our trip to Spain coming up. We are flying into Madrid, travelling to León and then Bilbao. Afterwards we’re off to Barcelona for a few days before flying back.

Mi esposa y yo estamos practicando nos español para el viaje. When we need to use the bathroom, we are fully prepared to ask, but hope they point rather than give us directions.

[Listening to: Namistai - Paul van Dyk - Out there and back (CD 2) (8:21)]

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FogCreek commissioned a documentary about their summer intern project named Aardvark which ended up releasing Copilot, a product to help your mom with her computer woes.

I think it’s intriguing in the voyeuristic sense in that I like the idea of taking a look inside how other companies manage their software projects. But at $19.95 a pop, It’ll have to be picked up by NetFlix for me to watch it, which doesn’t seem likely.

It makes me wonder if I should buy it as a show of solidarity to say there is a demand for documentaries and movies that provide a realistic view of software development.

Perhaps not surprisingly, software development doesn’t get much respect nor recognition in Hollywood. The depictions out there that do exist are typically ludicrous (Swordfish anyone?). Neither do television shows address the subject.

There are plenty of shows about lawyers and doctors, but what about the software developers? You can’t sit there and tell me that open heart surgery is more exciting than completing a refactoring on a method and getting green bars on your unit tests. Ok, maybe it is a tad bit more exciting as a life is on the line as opposed to someone’s butt, but the interesting part of such shows such as Grey’s Anatomy and Law and Order are the backstories, not the medicine nor law being practiced.

Comics like Dilbert give a hint at the comedy potential for a show depicting software developers. So c’mon Hollywood, copy this idea (since that is the modus operandi). I saved you the trouble from having to think of it yourself.

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Logged into my ad-sense account and noticed that Google started a referral program. Very cool!

If you love to blog, why not make a little extra spending cash doing what you love, eh? It’s nice to have another revenue stream, no matter how small.

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Toilet A while ago I wrote that a client often often does not know what he wants until he sees it. I was referring to software development, but this is common across many professional services organization, such as plumbing for example.

This week I had the opportunity to be on the client side of things when we noticed our toilet was leaking. I thought I knew what the problem was. It seemed to me that the toilet was leaking from its base. So I told the plumber that and he came in and tightened the base. No water seemed to be coming from the base afterwards so he left.

Later that evening we noticed that the carpet behind the toilet was still wet. So I looked carefully and noticed the flex tube from the stop valve to the tank was dripping water.

The next day the plumber comes back and he replaces the flex tube and leaves. I take a look and notice it is still leaking. I call him and he returns and finally figures out that the ring where the flex tube’s connects to the tank is the culprit, and replaces the flush valve and other inner components (I’m no expert in toiletology). It took him three trips to fix the problem with the throne.

1st Lesson: Get to the real root of the problem.\ All in all, the toilet was fixed, but the quality of service was poor. The lesson here is rather than simply assuming the client (in this case me) knows what he wants, take the time to perform due diligence. He is the professional. What do I know about toilets except that they’re great for pondering life’s mysteries.

As software developers, we have to take the time to gather proper requirements and ask the right questions. Our clients certainly know their own domains very well, but they don’t necessarily know a lot about software and how exactly software can help them.

2nd Lesson: Double Check Your Work.\ Once you do gather requirements and do the job, make sure you succeed in delivering what the clients want. It helps if you define clear acceptance criteria up front. For example, my acceptance criteria were very clear. I want my toilet not to leak. Ideally the plumber, knowing all he knows about plumbing, should be thorough in making sure that requirement was met.