Living in the Tech Avalanche Generation

Just as I was about to embark on  a new project (codenamed PONGO), the IronPython team announced a CTP 2.0 drop of the IronPython tools for Visual Studio 2010 which is exciting on a number of different levels.

If IronRuby and IronPython eventually make it all the way to Visual Studio integration in the full sense (that is packaged as part of Visual Studio itself) that would be a mark of first class citizenry.

What about Expression Blend?

Personally I work in both Blend and Visual Studio and even though the Visual Studio designer is somewhat improved and it’s intellisense is far superior than that of Expression Blend, it still does not provide me with the same fidelity or fluency in the design experience as I get from Blend. This leaves me with a problem when it comes to building applications where IronPython is the choice language.

It would have been unrealistic (at this stage) to expect Blend to open IronPython projects created in Visual Studio and sure enough that is the not case. What might be useful is Blend having a “design XAML only mode”, enabling it to open XAML files individually, taking advantage of the design experience it has to offer. Still not ready to give up on using Blend with XAML files that were part of a Visual Studio IronPython project, I set out to find a way.

Symbolic Links

The first thing I tried out was to see if Symbolic and Hard linked files would make the difference? First up I tried a symbolic link using the MKLINK utility:

MKLINK [[/D] | [/H] | [/J]] Link Target

Before doing this I created two projects, the first one an IronPython Tools project generated in Visual Studio and the second one a C# project created in Blend.

It should be obvious from the naming which project is which. In the blend project I removed the default XAML file generated by Blend.

Next came the file linking, I used only the Link and Target command line options, creating a symbolic link using the same name as the .XAML file in my IronPython project.

MKLINK pongo.xaml d:\temp\PongoBlend\pongo.xaml

Having successfully created the soft linked symbolic file I tried to add it to the Blend project only to find that it would not open – which, to blunt I wasn’t expecting to work. I was a little more hopeful however when it came to the Hard Linked file which I setup as follows:

MKLINK \H pongo.xaml d:\temp\PongoBlend\pongo.xaml

This did in fact open correctly in Blend and worked for a brief moment, when I changed something in Blend – Visual Studio would prompt me that the file had been changed outside the editor, unfortunately my celebrations were short lived when I found that the files were not updating in both locations when one or the other was subject to an edit. After some investigation and testing it appears that once opening the file in both the IDE’s the links would somehow eventually become broken and so the symbolic linking idea was now officially a lost prospect.

Duelling Projects

Finally I decided to synchronize two separate .XAML files in each of the two different projects, so the challenge was to find the most unobtrusive way of working in both IDE’s and easily syncing the the .XAML files after edits had been made. Given that one of the IDE’s was running a dynamic language with a REPL built in, I thought it shouldn’t prove too difficult.

What I did was to add two .py source files into the project, each one with some code that would sync in one direction, either from Blend to Visual Studio and vice versa. Sure its  far from a perfect solution but it just might be a price I’m willing to pay in the short term to get the benefit of using Blend. In the long term I really do hope that as the dynamic languages gain support in Visual Studio we also get some integrated ways to work in both IDE’s.

Here’s the very same Pongo.xaml file (or copy of it to be precise) in Expression Blend, but before you get too excited, the “send to interactive console” context menu option seems to suffer some kind of inconsistent behaviour (on my machine any way), causing the File copy operation in my .py files to work on only some occasions.

Undeterred I decided to fall back to an even more disintegrated experience and opt for running the synchronizing .py files in IPY.exe itself. This is easily achieved by associating .py files to the IPY.exe in Visual Studio using the context menu’s “open with” option, which is a something existing Visual Studio users will be very familiar with.

Like I said its far from a perfect solution and to be frank it’s somewhat annoying however my frustration is another thing altogether if I’m faced with doing all my layout and design in Visual Studio – so I will live with it for the moment. Hopefully the IronPython team and or the Expression Blend Team can find a solution that flows changes through more seamlessly in the short term and the perhaps in the long term allow us to open IronPython and IronRuby projects in Blend.

By the way if your wondering about the codename of the project that drove this adventure (PONGO) – the answer is yes if you guessed that it’s something that revolves around IronPython and MongoDB and I will be blogging about that more in the coming weeks.

One of the clear value added possibilities with IronRuby and IronPython (or any DLR language) has to offer is making applications scriptable. This opens the possibility for enabling scripting of your application, it’s types and potentially objects running in memory in your application at runtime. I recently went looking for an IronRuby console / shell window control written natively in WPF and turned up nothing. I did however come across some examples implemented for Windows Forms and the one that got my attention was Orion Edwards Embedded IronRuby Interactive Console.

Whilst Orion’s project provided the basis of what I was after, I was under no illusion that I would find exactly what I was after and would therefore have to build out the rest of the functionality I required.

The Basic Requirements List

• Reusable WPF User Control
• The Console should allow users to write script against in memory objects of the host application.
• Should persist (to a log) the state of variables in the IronRuby runtime scopes.
• Extensible Application Design and easily maintained and Testable.

So rather than re-invent the wheel I started out with Orion’s code and worked it into a WPF User Control that followed the MVP pattern. This version supports printing of all scope variable state to the console window, clearing of the console window text and all the out of the box access to the IronRuby runtime from the console itself. The IronRuby Console User control also allows the consumer application to pass through in memory variables from your managed CLR hosting application.

Finally I need to also make mention that some of the classes used to stream the STD/IO came directly from Ben Halls wonderful IronEditor. And before I forget, the code can found here on my blogs subversion repository.

Personally I have a pretty rapid fire kind of scanning action that allows me to try to find information that matches my requirement quickly. Sometimes I need to slow down when the topic is too deep, for example Databinding in WPF. The examples out on the web for Databinding WPF are not that great yet (IMO) and too many only touch the simplest kind of Databinding scenarios, focussing largely on how the data is structured and from a Models point of view (no pun intended). Models can get pretty deep and nested, yet for the most part the binding examples focus on the really trivial data scenarios where the depth is not considerable and furthermore often binding to static resources rather than data that came from the Database courtesy of an ORM or perhaps Astoria or even plain old ADO.NET. So enough complaining cause that wont change anything and like Roy said ‘what are you going to do about it’ ; time to get on with putting some examples together myself! Of course they will end up here when they are done.