Wiring Lokad-CodeDSL in a MightyMoose style.

Program.cs

// This is a hacky sample (that works for me) of alternative way to use Lokad-codeDSL
// or any similar way of generating message contracts on-the-fly. Original approach was 
// with using T4 template, that would rebuild cs files from DSL representation, whenever
// we hit Ctrl-S.

// This approach works almost exactly like this (Ctrl-S to rebuild), but does not require VS
// to run or does not require unloading VS to change the underlying generator code.

// in fact it is extremely boring. Lolcats from MightyMoose could be used to improve the situation, though.
// any takers? :)

// Original article with T4 approach is here:
// http://abdullin.com/journal/2010/10/12/teach-visual-studio-your-own-language-easy.html


// Essentially we just start our program in background and let it monitor files, rebuilding them
// on a save.

   class Program
    {
        static ConcurrentDictionary<string, string> _states = new ConcurrentDictionary<string, string>();

        static void Main(string[] args)
        {
            var info = new DirectoryInfo("..\\..\\..\\..\\Source\\Hub.Contracts");

            var files = info.GetFiles("*.tt");

            foreach (var fileInfo in files)
            {
                var text = File.ReadAllText(fileInfo.FullName);
                Changed(fileInfo.FullName, text);
                Rebuild(text, fileInfo.FullName);
            }

            var notifier = new FileSystemWatcher(info.FullName, "*.tt");
            notifier.Changed += NotifierOnChanged;

            notifier.EnableRaisingEvents = true;


            Console.ReadLine();
        }

        static void NotifierOnChanged(object sender, FileSystemEventArgs args)
        {
            if (!File.Exists(args.FullPath)) return;

            try
            {
                var text = File.ReadAllText(args.FullPath);

                if (!Changed(args.FullPath, text))
                    return;

                Console.WriteLine("{1}-{0}", args.Name, args.ChangeType);
                Rebuild(text, args.FullPath);
                SystemSounds.Beep.Play();
            }
            catch (IOException) {}
            catch (Exception ex)
            {
                Console.WriteLine(ex);
                SystemSounds.Exclamation.Play();
            }
        }

        static bool Changed(string path, string value)
        {
            var changed = false;
            _states.AddOrUpdate(path, key =>
                {
                    changed = true;
                    return value;
                }, (s, s1) =>
                    {
                        changed = s1 != value;
                        return value;
                    });
            return changed;
        }

        static void Rebuild(string text, string fullPath)
        {
            var generator = new TemplatedGenerator();
            var contents = GeneratorUtil.Build(text, generator);
            File.WriteAllText(Path.ChangeExtension(fullPath, "cs"), contents);
        }
    }