News

How to reset the web.config in a ASP.NET MVC 3 sub application

Sun, 15 Apr 2012 11:57:07 GMT

Ever wanted to add a new web application that can serve out static resources from a subdirectory in your MVC 3 site?
I ran into this issue the other day since my web hosting provider is somewhat limited when it comes to IIS configuration. I want to run a Orchard site (MVC 3) in the root folder, and also have the possibility to create multiple new standalone web applications to its sub directories. Applications that is completely isolated, non .NET, HTML5/Javascript sites.

What is the problem?
By design, web.config is inherited through the whole web application, a MVC app installed in the root will therefore require all sub directories to implement MVC as well.

If we simply add a plain HTML/JavaScript site to a sub directory (configured as a web application in IIS), it would respond with a yellow-screen-of-death stating that required MVC dll’s is missing:

Parser Error Message: Could not load file or assembly 'System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.

Removing dependencies from our new web.config
Normally we use our web.config to specify what dependencies to load. This time around, since we don’t want to use any .Net we have to create new web.config to specify what dependencies to remove.
And what exactly are our dependencies? More or less all <add> tags in our root web.config, needs to be removed with an <remove> tag in our new web.config. The result now looks something like this:

The last part is kind of tricky though. See below how the default <web.server><handlers> are cleared and a NotFound handler is added for all the 404 requests? After removing the NotFound handler we need to re-add the default handler for serving static files, the one Orchard had cleared. Otherwise no requests would be handled at all.

And that should do the trick!

/love Carl

The Orchard root web.config for reference:

TDD in a WPF world - Testing the ViewModel

Mon, 19 Dec 2011 22:51:54 GMT

Here is a sketch of the basic principles I follow to make my ViewModels more testable:

I follow the following steps when designing the ViewModel above:

Create a prototype of the View. This will get me a clear picture of the requirements on the ViewModel.
Write a test.
Write the code necessary to make the test turn green.
Repeat steps 2-3 until the ViewModel is complete. Refactor as necessary.

/love Carl

Testing the PropertyChanged event

Mon, 19 Dec 2011 22:50:27 GMT

Testing a ViewModel and it's properties may look quite easy at first. But ViewModels are quite treacherous to their nature. There's no guarantee that the value of a property in a unit test is the same as what the view is displaying, because of NotifyPropertyChanged (if no PropertyChanged is fired, nothing is updated in the view, right?).

And really, what use do you have of a unit test that you can't fully rely on?

I thought about solving this issue a few days back and came up with a small extension helper method that increases the test accuracy without increasing the complexity too much.

Given this Context:

    [TestFixture]
    publicclassWhen_updating_a_property_which_a_WpfControl_is_binding_to
    {
        privateViewModel _viewModel;
 
        [SetUp]
        publicvoid Context()
        {
            _viewModel = newViewModel();
            _viewModel.PropertyWithWPFBinding = 100;
        }
 
        [Test]
        publicvoid It_should_display_the_correct_value_since_it_has_fired_a_propertyChanged_event()
        {
            Assert.That(_viewModel.PropertyWithWPFBinding, Is.EqualTo(100));
        }
    }

The test will certainly pass both with or without PropertyChanged (which is bad).
So with a small modification, and with the use of Should BeDisplayedAs():

    [TestFixture]
    public class When_updating_a_property_which_a_WpfControl_is_binding_to
    {
        privateViewModel _viewModel;
 
        [SetUp]
        publicvoid Context()
        {
            _viewModel = newViewModel();
            _viewModel.MakePropertyChangedAware();
            _viewModel.PropertyWithWPFBinding = 100;
        }
 
        [Test]
        publicvoid It_should_display_the_correct_value_since_it_has_fired_a_propertyChanged_event()
        {
            _viewModel.ShouldBeDisplayedAs(x => x.PropertyWithWPFBinding, 100);
        }
    }

The test will fail if no PropertyChanged was fired. To avoid confusion I also added a more descriptive fail reason:

Pretty sweet.

What the code really does is simply creating a listener for all ProperyChanged events that has been fired with the MakePropertyChangedAware() method. And records the values of the ViewModel only if a PropertyChanged is fired.

If you want a sample project and the source, download here.

/love Carl

TDD in a WPF world - Disconnecting the MessageBox

Wed, 08 Sep 2010 21:03:51 GMT

Starting TDD'ing our new ViewModel designed app, will soon get us cornered. There are a few pitfalls and hairy situations that will arise quite early on. But, they will mainly get there for one reason: not following the rules. And with rules, I'm refering to the two principles I was mentioning earlier:

Keep your interface thin, and use loosely coupled objects.

Devil Doll says:
" This can't hardly be all! I just popped up a messagebox in my application. How can I write a unittest for that? I don't get it. "

Let's examine our MVVM pattern more closley. In my opinion and quite easily explained: the Model should not know about anyone. The ViewModel should only know about the model. And the View should only know about the ViewModel. This leads to the following fundamental principle: "Don't put any WPF aware code in the ViewModel!" If there is a single "using System.Windows.*" in your ViewModel class, you have failed, miserably (well in some cases it's actually needed, the important part here is that you should know when you're breaking the rules and why). And your objects is probably not so loosley coupled anymore. If I ever need to write WPF specific code, I usually prefer using the ValueConverters, and even then, keeping them as thin as possible.

Devil Doll says:
" But still... The messagebox? Where should I put it? "

Ok, let's give it a try:

      
        class InvoiceViewModel
    
      {
    
          public void CreateInvoice()
    
{
    
              if(MessageBox.Show(
    
    "Are you sure you want to create
a new Invoice") == MessageBoxResult.OK)
    
{
    
    var invoice = new Invoice();
    
SaveInvoice(invoice);
    
}
    
}
    
      }

This method is wrong in so many ways. Not only does our ViewModel use WPF specific controls, our class also have hard dependence on some kind of window needed for the show function. More than that the mere presence of the messagebox is making this function completely impossible to test. Horrible! Our first step should be to decouple it:

      
        class InvoiceViewModel
    
      {
    
          IDecoupledMessageBox decoupledmessagebox;
    
          public void CreateInvoice()
    
{
    
              if(decoupledmessagebox.Show(
    
    "Are you sure you want to create
a new Invoice") == MessageBoxResult.OK)
    
{
    
    var invoice = new Invoice();
    
SaveInvoice(invoice);
    
}
    
}
    
      }

Woah, that was easy! Continue with cutting out the ugly WPF-stuff:

      
        class InvoiceViewModel
    
      {
    
          IDecoupledMessageBox decoupledmessagebox;
    
          public void CreateInvoice()
    
{
    
              if(decoupledmessagebox.Show("Are you sure you want to create a new
Invoice"))
    
{
    
    var invoice = new Invoice();
    
SaveInvoice(invoice);
    
}
    
}
    
      }

Devil Doll says:
" An IDecoupledMessageBox property in my class? That smells, I don't like it... "

Hm, well then.. You could use Unity as Service Locator, like the following simplified example (which will of course leave you with a Unity dependency instead :(... )

class InvoiceViewModel
{

          [Dependency]
    
Microsoft.Practices.Unity.IUnityContainer unityContainer;
    
...
    
          public void CreateInvoice()
    
{
    
              if(unityContainer.Resolve<IDecoupledMessageBox>()
    
.Show("Are you sure you want to
create a new Invoice"))
    
{
    
    var invoice = new Invoice();
    
SaveInvoice(invoice);
    
}
    
}
    
      }

The implementation of our IDecoupledMessageBox class should be quite obvious. But what happened to our window?
Well it's now safely tucked away inside our DecoupledMessageBox. Someone has to put it there though, but someone else, definitley not our ViewModel, more likley our Module or Bootstrapper (or whoever pops up our Windows).

This solves it, we can finally wirite a unittest. And with some creativity, it also opens up for some interesting mocking scenarios:

[TestFixture]
public class InvoiceTest_When_User_Always_Approve

      
      {
    
          InvoiceViewModel invoiceViewModel;
    
          [SetUp]
    
          public void Setup()
    
{
    
invoiceViewModel =
    
                    new InvoiceViewModel(new AlwaysAnswerYesMessageBox());
    
}
    
          [Test]
    
          public void It_Can_Create_Invoice()
    
{
    
invoiceViewModel.CreateInvoice();
    
              Assert.That(invoiceViewModel.IsInvoiceCreated, Is.True);
    
}
    
      }

Beautiful!

/love Carl

TDD in a WPF world - The self injecting View

Wed, 08 Sep 2010 20:58:17 GMT

Occasionally, the ViewModel needs to communicate with the View. Most of the times, this is done with bindings. For i.e, activating and deactivating a control at a specific time is easily solved with a binding to an IsActive property on the ViewModel. Bindings is quite nice in this aspect, they maintain low coupling.

But sometimes this is not sufficient. In a recent project, I was using an Infragistics grid, where some properties on the grid simply couldn't be bound to (or I at least couldn't figure out how to).

Devil Doll says:
"Grr.. I hate stupid third-party vendors"

After some pondering over this new dilemma I came to the following conclusion:

The View must be injected, to make it possible to stub in a unit test.
It would be great if the View could inject all by itself, (since this was a rare occurance a wanted to isolate the anomaly).

The solution: The DataContextChanged event

    
      public partial class ViewControl : UserControl
    
    {
    
        public ViewControl()
    
        {
    
InitializeComponent();
    
            DataContextChanged +=
(ViewControl_DataContextChanged);
    
        }
    
        void ViewControl_DataContextChanged(object sender,DependencyPropertyChangedEventArgs e)
    
        {
    
            var viewModel = DataContext as IViewModel;
    
            if(viewModel != null)
    
            {
    
                viewModel.View = this;   
    
            }
    
        }
    
    }

The DataContext can be set and changed by anyone, and the View will inject itself automatically. Pretty nifty, and unit tests can now simply inject a stub instead.

/love Carl

ASP.NET MVC 2 session in march

Wed, 08 Sep 2010 20:31:13 GMT

A new, exciting and free (!) session is coming up in march: "ASP.NET MVC 2.0 & vänner". The session starts at 17.00 at the Jayway office on Drottninggatan. Read all about it here.

Be there, I will!

love carl

Silverlight Workshop

Wed, 08 Sep 2010 20:30:45 GMT

I'll be attending a workshop as an assisting tutor at Öredev this year. The workshop is lead by Anders Rundqvist, egotronic.com.

check it out at: ÖREDEV.ORG

ALTdotNET unconference - 12/9

Wed, 08 Sep 2010 20:30:22 GMT

It's finally time for a new unconference in stockholm. This time it's with the fine peoples over at Sogeti.

Lightningtalks, Open space and lots of interesting progressive discussions.

Be there - I will.
/love Carl

Silverlight 3 - one step closer to web nirvana - 16/9

Wed, 08 Sep 2010 20:30:07 GMT

A colleague of mine, George Bolsch, will hold a talk about Silverlight 3 in a few weeks over at Dotway in stockholm.
Feel free to drop by for some free snack, along with two action-packed hours of web nirvana.

Seriously, George is really talented and usually holds really interesting sessions. Highly recommended!

Register here, 16 September

Be there! I will.
/love Carl

Scott Bellware @ Sthlm ALT.NET

Wed, 08 Sep 2010 20:29:28 GMT

This saturday, 18 april, Scott Bellware visits sthlm for an "informal Open Space on progressive software development" (whatever that means).
Hopefully, mr. Bellware gets his hardware working this time around.

Be there, I will...

/love Carl

TDD in a WPF World - Setting the scene

Wed, 08 Sep 2010 20:27:55 GMT

Two fundamental nessecities for testing our WPF applications are:

Keep the user interface layer (Xaml) thin.

Xaml is a bit trickier and more tedious to test than plain c#. I always try to keep a focus on testing as much c# as possible, not Xaml.

Devil Doll says:
"Crazy! How can you keep the code coverage up? It should be at least at 100%. Ignoring the Xaml will never get even close to that level!"

True. But it's not just because I'm lazy, it's also to enforce good design. The 100% does not, according to me, mean 100% of the entire application, but 100% of what matters, mainly: logic. So to achieve this, we have to move as much logic as possible from the UI to our business layer. And in my opinion, whether doing TDD or not, business logic should never be in Xaml (hm, "separation of concerns" anyone?), TDD just makes this painfully obvious.

Devil Doll says:
"Ah I can see what your aiming at here, It's pretty easy to remove the logic from the xaml, but this leaves me with loads of new code floating hanging around, where should I stow it? s" type="text/javascript"> "

This is where a good pattern which helps us separate the Logic from Xaml is needed. You may pick your favourite one, but for WPF, I'll pick the Presentation Model, or more commonly named (or renamed by Microsoft) Model-View-ViewModel.

Loose coupling.

This is really a necesity to unittesting in general. And to implement the ViewModel effectively Inversion of Control is a must. I prefer using some kind of IoC container and in the following parts of the series I'll be using Unity.

Devil Doll says:
"Unity? Are you sure? I heard that Unity sucks!"
Maybe, but I'll keep it at a low level so you will not even notice that it's Unity behind the scene. You can of course use your "altdotnet" container of any flavour.

So to put all this this to practice, I'll get right down to some hardcore coding in the next part of the series: "Disconnecting the MessageBox".

love Carl

INotifyPropertyChanged - A remedy for the plague

Wed, 08 Sep 2010 20:26:01 GMT

I stumble over this nice little extension class the other day while visiting Google.

Instead of passing around a hard coded string for NotifyPropertyChanged like this:

    private string firstName;

    public string FirstName

    {
  
    get {  return firstName; }
    set
    {
        firstName = value;
        OnPropertyChanged("FirstName");
    }
}

A lamda expression takes care of the dirty stuff:

PropertyChanged.Notify(()=>this.FirstName);

This magic is accomplished with a small extension class which can be downloaded at Einars blogg, over here.

Pretty cool.

Progressive .NET Days in Stockholm

Thu, 02 Sep 2010 20:54:46 GMT

I had the fortunate opportunity to attend an unconference led by Scott Bellware a few months ago. Scott is such an inspiring character and all his speeches about Progressive development and Lean thinking profoundly changed the way I look on software development today.

Bearing this in mind, I'm really excited hearing that Scott is returning to Stockholm again in august!! And this time he also brings some friends with him.

Awesome!

Guys like:
Dave Laribee, Ayende Rahiyen, Scott Allen and Jimmy Nilsson will hold workshops in areas like:
NHibernate - MVC - Context Specification - Application Testing and Specification - Lean and Kanban - Git - Cloud computing architecture

This will be two days in heaven ;). read more here

Be there! I will
/love Carl

Cybercrime: The Devil in The Dark - 21/9

Thu, 02 Sep 2010 20:53:45 GMT

Security expert Andy Malone (whose name sounds like a chicago gangster from the fifties) drops by Stockholm on monday the 21th (september). Andy will hold a session about security for developers.

Sounds interesting (and it's of course free), I think I'll pop by.

What absence yields

Thu, 26 Aug 2010 08:00:46 GMT

After years of absence this blog finally found itself a purpose.

With start today, a new ongoing series will start under the title: TDD in a WPF world.
It will cover certain problematic aspects of developing in the presentationlayer with Windows Presentation Foundation from a test driven design approach. And how to solve them using techniques like Model View View-Model, Dependency Injection, IoC Containers, CompositeWPF, Mock / Stub, etc.

In the meantime, while you wait for the first post, I would recommend you listening to: "Detektivbyrån's" new album, "Wermland"

love Carl

Visual Studio 2008 open space tour

Thu, 26 Aug 2010 07:59:23 GMT

Free interpretation by Google :) - www.dotway.se

Be there!
I will.

Lanseringsresan then continue in the autumn when Dotway drag around in four locations and arranges Visual Studio 2008 and Microsoft. NET Framework 3.5 Open Space!

< /span>This arrangement is supposed to be in the form of a nice evening with a piece of food and little good to drink, and that we are talking about them, presents and labbar with what interests us most of these new technologies. Du kan själv med fördel ta med dig något du vill visa på din egen dator eller låna en av oss på plats. You can usefully take with you anything you want to display on your own computer or borrow one of us on the spot.
Open Space works best when each to contribute material to the best ability and to secure up to the whole floating in and working correctly will Dotway to have several experts on site loaded with materials that can help the discussions and who has long experience of to have tested these technologies are already in their infancy during alfastadiet.

The food is served from 17.00 and at 17.30 at the start Visual Studio Open Space.

In order to calculate matåtgången, we want you the latest on the above-stated last pre-notification you to the desired orts e-mail address. In addition, we'd like to know if you have any special requests concerning the diet.

Thank you!

Autumn's agenda for Sweden Visual Studio 2008 and. NET Framework Open Space and Heroes Launch Event Tour:

Location	Location	Date	Time	The last date of notification
Malmö	Dotways office Hans Michelsensgatan 9	25/8	17:30	22/8 - malmo@dotway.se
Gothenburg	Dotways office Little Bommen 6	28/8	17:30	25/8 - goteborg@dotway.se
Linköping	Dotways office Teknikringen 8	1/9	17:30	28/8 - linkoping@dotway.se
Stockholm	Kompentenscenter Stockholm Vasagatan 8-10	11/9	17:30	1/9 - stockholm@dotway.se

Interesting session coming up

Thu, 26 Aug 2010 07:58:55 GMT

Ever wondered whats cooking on the darkside theese days? Renowed Rickard Öberg drops by the Stockholm office to show som new tricks from his Qi4j framework. The session is on the 26th januari and free of charge (read more here).

Sounds really interesting and i can really recommend it, unfortunatley I wont be there since I already got a date with Jim Coplien that day.

By the way:
Google just told me that Roger Alsing is working on a .Net port... awesome!

/love Carl

Exciting upcoming weeks - a prelude to Øredev

Thu, 26 Aug 2010 07:58:22 GMT

The upcoming weeks looks promising, full of interesting seminars and "geek gatherings" all over Stockholm. In other words, it it's the perfect warmup for the King of Developer Conferences - Øredev in the first week of November.

Oktober:
Monday / 19th
- Entity Framework 4.0 (Dotway)
- Using the cloud for testing (Jayway)

Tuesday / 20th
- Geek Meet with Molly and HTML 5 (Bwin)

Wednesday / 21th
- Limited WIP Society (Kanban) (Avega)

Thursday / 22th
- Digital vs Fysiskt (multitouch) (Inuse)

Monday / 26th
- Det behövs mer än bara user stories (Agical, GeekNight)

November:
Monday -> Fri-day / 2th - 6th
- Øredev (Malmö)

And the best of all... They're all free ( ... well almost all of them :-) )

See you there
/love Carl

Upcoming free events in STHLM april

Thu, 26 Aug 2010 07:58:10 GMT

Lots of inspiring events is coming up:

8/4: Stockholm GTUG, with Google Go, WebGL and Geocoding API.

12/4: Visual Studio 2010 - The Ultimate Tour, microsoft release party!

19/4 Real world Scala, at the Stockholm Jayway office

20/4 Stockholm Web Monkeys, HTML, CSS and JavaScript galore!

22/4 Reactive Extensions for .NET, at the Stockholm Jayway office

/love Carl

New blog

Thu, 26 Aug 2010 07:52:38 GMT

Stefan Severin, a collegue from Dotway just started a new exciting blog,
with a focus on Oslo, and other M-stuff.
It looks very promising. Check it out at: stefanseverin.wordpress.com. Someday I'm gonna learn all these new neat stuff aswell...

love Carl