More than two months since my last post. Which means I suddenly have a lot to say. Beware, rambling may follow… Nearly five months ago I claimed to be making “rapid progress with language learning”. Well obviously not rapid enough to actually reveal anything. Well that might be at an end soon.

One of the problems of writing the app using things like LINQ means most people will have other things to install to use the app (.NET 3.5 specifically - and possibly .NET 3.0 for non Vista users) and even then it’s limited to Windows users as Mono support for Windows Presentation Foundation will be a long way off (if they do it all). Since Silverlight 2.0 is supposed to be really cool and now supports a big chunk of the widgets from standard WPF (and has has quickly developing Moonlight support), why not write the app in that? So that’s what I’ve been doing. And it was a lot easier than I thought.

The first piece of easiness I found was that I only had to make like three changes to my non-UI code to make it compile as a Silverlight DLL. Unfortunately I can’t persuade Visual Studio to compile it as a Silverlight DLL and a normal DLL in one go, so I’ve currently got the same code added as two different projects and I copy the code between them (not ideal). The only real work I had to do was reimplement my data provider. When I started, I cunningly made sure that all resources (lessons, media, user progress) were grabbed from a data class. I wrote a new class that fetches it from a RESTful server (more on that in another post). So hopefully, a nice Silverlight version of the app will be public soon.

About Silverlight

For those that don’t know, Silverlight is Microsoft’s answer to Flash. Apparently. I’m not sure if it’s that a good analogy really. Silverlight 1.0 basically gave you access to a nice environment to draw things in the browser and then manipulate it with Javascript. Or something. To be honest I didn’t really care about version 1.0 since writing complicated things in Javascript doesn’t sound like fun. Silverlight 2.0 (formerly Silverlight 1.1) on the other hand gives you that same environment but the ability to manipulate the things with compiled .NET assemblies written in any CLR language and comes with implementations of a lot of the widgets in the WPF.

I’ve been vaguely using Google Docs (specifically Spreadsheets) since it came out but never to do anything actually important. Most of the time I just had a list I need sorting, or if I was feeling sophisticated I’d use it to decide on what was best value for money (how much £/GB a range of hard drives were for instance). Recently I started using it to plan lessons for the language learning app. The ability to use it from work (or any other computer I might be on - including viewing it on my Nokia 770) was useful, but in the end I was only really writing a list with it.

Until now. I now have a nifty little C# app that generates modules directly from a Google Spreadsheet which is definitely a Good Thing. I’ve been thinking of writing an app for module editing for a while since writing them by hand is tiresome and error prone. Google Spreadsheets does half the work for me by providing the user interface for generating a table and then provides access as simple XML. Which brings me to the matter of actually accessing the data. Google provide a client library in C# for accessing quite a lot of their API. I tried using it but found it a little confusing. Luckily since I was just wanting to query data, I discovered that raw access was actually easier. You simply make a GET request to http://spreadsheets.google.com/feeds/worksheets/_key_/public/values (where key is provided to you when you “publish” a spreadsheet - access to unpublished spreadsheets requires authorization which is more complicated). This gives you an Atom feed of URLs to the individual worksheets which them contain Atom feeds of either rows or columns (your choice). The query power of LINQ (along with XElement, XAttribute etc.) make transforming the feeds into modules really easy. In fact the code that does the hard work (takes a spreadsheet key and generates the XML) is only 102 lines long, and that’s including unnecessary spacing to make the LINQ more readable (the main LINQ query is 35 lines).

The secretly named language learning app has been revamped to use LINQ for most of the XML handling. For those that don’t know, LINQ is a new technology that provides querying functionality in the .NET world. In my case I’m using LINQ to XML and it has seriously cut down on the size of the heaviest methods. Also, the part of LINQ to XML that I found least interesting when I read about it is actually the part I’ve found the best - the new XDocument API. Anyway, LINQ combined with a new USB headset that provides some actually quite good audio means that the important fundamental features have been implemented and work. At the moment it can:

• Generate lessons based on vocabulary1 modules
• Generate lessons containing past content with the correct repetition timing.
• Actually play the lessons (but only on Windows2)

There are a few more things I want to add before I release any of it (like more audio for a start). But I thought I’d at least point out development is still happening :o) 1Instead of the Conversation > Phrase > Term style of Pimsleur I’ve decided to go for a more freeform approach to start with (inspired by me listening to Michel Thomas again). A vocabulary module just contains list of words and phrases that are processed in order. 2I still need a cross platform way to play audio. At the moment I use MCI which is part of winmm.dll which is obviously Windows only. Although Wine has apparently implemented it almost completely but I’m not sure how I’d go about making that help me.