Yet another command-line option parser.
- Intended for cases where subcommands are required (like git or svn)
- Nearly POCO classes: they need to inherit an interface and implement one method (
Execute()). - Works well with IoC containers - resolve all command objects in one fell swoop
- No dependencies
For each subcommand, implement a class that inherits the ISubCommand interface, which requires implementing one method (Execute) that is called to run the command. In your main function, create a Parser object and call Parse(args), which will return the command to run. If no command is specified, the returned command will be a built-in Help command. Any errors (unknown command, for example) will throw a CommandLineParserException.
using Yaclops;
public class AddCommand : ISubCommand
{
[CommandLineOption(ShortName="n")]
public bool DryRun { get; set; }
public void Execute()
{
// Execute the command....
Console.WriteLine("Add command!");
}
}
static void Main(string[] args)
{
try
{
var parser = new CommandLineParser(new ISubCommand[] { new AddCommand(), new DiffCommand() });
var command = parser.Parse(args);
command.Execute();
}
catch (CommandLineParserException ex)
{
Console.WriteLine(ex.Message);
}
}
Creating the commands is a little awkward, but the intent is that an IoC container, such as AutoFac, will be used, which makes it much cleaner:
static void Main(string[] args)
{
try
{
var container = CreateContainer();
var parser = container.Resolve<CommandLineParser>();
var command = parser.Parse(args);
command.Execute();
}
catch (CommandLineParserException ex)
{
Console.WriteLine(ex.Message);
}
catch (Exception ex)
{
Console.WriteLine("Unhandled exception in main.");
Console.WriteLine(ex);
}
if (Debugger.IsAttached)
{
Console.Write("<press ENTER to continue>");
Console.ReadLine();
}
}
private static IContainer CreateContainer()
{
ContainerBuilder builder = new ContainerBuilder();
// Command-line specific stuff
builder.RegisterAssemblyTypes(Assembly.GetExecutingAssembly())
.Where(t => typeof(ISubCommand).IsAssignableFrom(t) && t.IsPublic)
.SingleInstance()
.As<ISubCommand>();
builder.RegisterType<CommandLineParser>();
return builder.Build();
}
More examples forthcoming. The included Sample project has additional examples.