.NET & Funky Fresh : WPF, NHibernate

Porting NHProf from WPF to Silverlight – Day 8

Rob Eisenberg — Fri, 09 Apr 2010 20:19:00 GMT

Day eight* of the port and I was so happy not to discover any new issues. At this point I have almost all the major UI pieces in place. You can now see what you would normally during typical profiler usage. There’s still a lot of work to be done…probably much more than has been done so far. I still have a few big pieces such as query results and query plans. I also have to re-enable multi-selection of sessions and statements because the mechanism we were using in WPF isn’t going to work exactly the same for Silverlight. We’ve got to rebuild all our control templates and styles. None of those will port. I have to add context menus back in and hook up the help system too. There are a few other smaller things like that to look into. There are plenty of other issues to solve, but everything in its own time :)

*I’m not actually working full eight hour days on this project. I usually end up spending about 4-5 hours per day on average.

Porting NHProf from WPF to Silverlight – Day 7

Rob Eisenberg — Wed, 07 Apr 2010 02:21:00 GMT

Today I worked on statements. They flow pretty naturally out of the sessions functionality. I still have a lot of work ahead of me, so fortunately I only found two new issues today. I was able to rework Xaml in both cases fairly easily.

Binding in it’s Element form is not allowed. Fortunately, I was able to rework it as a markup extension.
ContentControl.ContentStringFormat is missing. I was able to use the StringFormat built into the BindingExtension instead.

Screenshot is below. Aside from the hideous styles…it’s actually starting to resemble itself.

Porting NHProf from WPF to Silverlight – Day 6

Rob Eisenberg — Mon, 05 Apr 2010 21:44:00 GMT

I started working on the most complicated part of the UI: Sessions. There are a lot of different view models and views related to this part. Fortunately, by now, I think I have found most of the issues. But I’m still encountering a few new issues here on day six. Below is the customary screenshot and issue list.

Styles don’t have Resources. We are probably going to have to re-write all of our styles and control template. So, our new solution will take this into account.
ControlTemplate cannot have triggers. See above.
ControlTemplate cannot have resources. See above.
Uri is missing PathAndQuery – I implemented this manually by combinding AbsoluteUri and QueryString with a ‘?’ in between.
MultiBinding is missing. We are going to do some major rework on that view unfortunately. I’ll try and provide more details later. Skipped it for now…
No ReaderWriterLockSlim. This was surprising. I really wasn’t sure what to do, so I used a standard lock for now.

Porting NHProf from WPF to Silverlight – Day 5

Rob Eisenberg — Fri, 02 Apr 2010 16:31:00 GMT

Well, I’m pleased to say that on Wednesday I only encountered one new* issue during the port. ListBox does not support grouping. One neat thing in WPF is that all the items controls supported grouping. One of the reports we had was a set of master/details grids where the master was a grouped ListBox. Needless to say, this entire report had to be redesigned to work around this issue. Truth be told, I never really liked the way that report was set up. As a solution I decided to use the Silverlight DataGrid with two levels of grouping. That issue aside, it was pretty quick work to port all the reports. As part of the process, I made the reports mechanism a little easier to maintain. Basically, anything that implements IReport will appear in the report list, will be added to the reports menu and will automatically have its view bound appropriately. Yay for IoC and Caliburn! Here’s a screenshot:

*Just as a reminder: When I say “new” issues I don’t want to insinuate that it is the “only” issue I encountered while working. I have encountered dozens of issues every day. But I am only recording here issues that I find that I haven’t previously encountered on this project. Trying to track every “instance” of an issue would be unmanageable.

Porting NHProf from WPF to Silverlight – Day 4

Rob Eisenberg — Thu, 01 Apr 2010 18:36:00 GMT

On Tuesday I spent a decent amount of time fleshing out the last remaining features under the Options menu. I then did some general reorganization to the project structure. Along with the port to Silverlight, I’ve been upgrading the application to use Caliburn 2.0 which is working out exceedingly well :) In fact, some of Caliburn’s features are making it very easy to work around the differences between the WPF and Silverlight platforms. After the reorganization, I decided I would start porting over the reports. As has been my pattern, below is a screenshot and the list of *new* issues I encountered. I’m really glad there weren’t as many as on Monday…

UpdateSourceTrigger=PropertyChanged is missing. There are workarounds which wire for events and manually update the bindings. I used Caliurn 2.0’s C over C binding to do this automatically :)
RelativeSource FindAncestor is missing. Fortunately, I replaced our homegrown grid with the Silverlight DataGrid and was able to eliminate the need for this in this scenario.
Hyperlink.Tag is is missing. Strange isn’t it. I reworked the code to use a HyperlinkButton.
Binding.StringFormat syntax is different. In WPF, you escape like this Text="{Binding AverageStatementsPerSession, StringFormat={}{0:0.#},FallbackValue=0}" but that causes a compile-time error in Silverlight. What is worse is that it doesn’t tell you where. It just complains that there is something wrong with a markup extensions somewhere in your Xaml. I fixed it with the following change Text="{Binding AverageStatementsPerSession, StringFormat=\{0:0.#\},FallbackValue=0}"
GridSplitter is missing ResizeBehavior and ResizeDirection. Fortunately, it seams to work pretty well without them. I have a couple of issues with this that I still need to look into though.

Porting NHProf from WPF to Silverlight - Day 3

Rob Eisenberg — Wed, 31 Mar 2010 13:58:00 GMT

On Monday I spent a good four hours working on the port. I decided to flesh out the functionality of the Main Menu. As I mentioned before, none of the menu controls available support commanding. Fortunately, Caliburn has its own mechanism which is much richer than what you get out of the box anyways. So, I began hooking this up, fleshing out the appropriate commands and implementing the various features of the application related to them. This approach actually brought me in touch with a very wide range of the application’s features. As a result, I ended up hitting a lot of issues. I calculated, that on average, I was hitting a *new* API issue (one I hadn’t seen previously on this project) every ten minutes for the entire four hour period. That was frustrating to say the least. Below is a (hideous) screenshot and a list of the issues I hit.

Style.Triggers are not supported. Ultimately this means we are going to have to refactor a lot of styles. Temporary fix to get things running was to comment out the triggers ;(
DataTrigger not supported either. We’ll probably end up refactoring to VSM. Unfortunately, many of our DataTriggers are in Styles…Fixing this is going to be interesting.
Custom Markup Extensions are still not supported in SL4, even after they completely re-wrote their Xaml parser from the ground up to support greater extensibility. My particular scenario was easy to work around by creating a custom IValueConverter. Another reasonable solution might be to create custom attached properties.
Lack of Command Support on Menu controls – This is not a problem with SL4 (except that it doesn’t have any menu controls), but is an issue with the current 3rd party controls. As I mentioned above, Caliburn made this easy enough to work around.
OpenFileDialog is missing CheckFileExists, Title, FileName and RestoreDirectory – We can work around all of this. The major consequence is that the user’s experience with the OpenFileDialog will be degraded.
Missing Timeline.DesiredFrameRate – Apparently you can’t control animation frame rate in Silverlight. I don’t think this will be a major issue.
The following simple storyboard scenario does not work. There’s seams to be a problem setting Storyboards with StaticResource. I used a bit of code-behind to start the animation. There’s probably a better way. Anyone have an idea?

SaveFileDialog missing Title and FileName – Again, this can be worked around. Mostly it involves a degraded user experience.
Process.Start is missing – There was talk of getting something like this into SL4. It would have been nice. We need it to open default apps for certain file types on the OS. We’ll either do without this or push it to our backend (which is not Silverlight).
Enum.GetValues is missing! I found this nice workaround: http://www.dolittle.com/blogs/einar/archive/2008/01/13/missing-enum-getvalues-when-doing-silverlight-for-instance.aspx
File.WriteAllText is internal. It would have been nice to have this, but we can work around it using Streams, etc.
Missing SystemParameters.PrimaryScreenHeight and SystemParameters.PrimaryScreenWidth. We’ll just have to do without…
Missing Serializable and BinaryFormatter. This is a real pain. Many people have asked for this since SL2, but the SL team hasn’t shown any interest in providing this. We are going to have re-write our user settings mechanism.
Missing Button.IsDefault and Button.IsCancel. This can be worked around. It means adding custom keyboard wire-ups for modal dialogs. Yuck.
No Label control – Now that we have ElementName binding why don’t we have a decent label control with Target and ActivatorKey? In the mean time I am using a TextBox. We’ll probably have to fix this with a custom control.
Bindings on DPs don’t default to TwoWay where appropriate. This is mostly an annoyance.
No ValueConversionAttribute to decorate value converters with. Not a big issue. But you need to remove it before you can compile.
Missing Visibility.Hidden. Again, not a big issue. But, you will need to rework code that uses this to use Opacity and IsHitTestVisible.
Missing DependencyPropertyKey. – We had a custom control that required this. We will have to re-write this control.
Missing FrameworkPropertyMetadata. – Same as above.
DependencyProperty is missing OverrideMetadata – Same as above.
TextBox is missing MinLines and MaxLines – We’ll manage without this by hardcoding height in pixels (yuck!)

NH Prof Public Beta

Rob Eisenberg — Fri, 02 Jan 2009 16:01:00 GMT

Christoper and I have had the privelage of helping Ayende to build the UI for his NHibernate Profiler over the last couple months. Yesterday evening he released the public beta with a 30 day trial version. If you are using NHibernate, get over to the product site and download the beta. This is going to be an invaluable tool for developers using NHibernate and you can get it at a special price if you purchase during the beta period.

As a developer on this project, I had the unique opportunity to watch a master at his craft. The architecture of the product is clean and Ayende has managed to jam pack this version with a ton of NHibernate smarts. Just working on it, I gained a deeper understanding of the types of problems one can run into while using an ORM. I would not want to do another project without it.

Another exciting aspect of this application is that we are using the latest version of Caliburn in the UI architecture. Generally speaking, the UI architecture is composed of a very rich Presentation Model (MVVM) with a splash of MVP for good measure. There is almost no code-behind in the views. All communication is handled by Caliburn's action message mechanism. We were also able to use Caliburn's new testability features to cover all our views with data binding validation tests and do basic property change notification testing.