command handler

Introduction

Commands can be intercepted and changed as they pass through Pipeline of Command Handlers before executing.

Example

Let's intercept the PlayerSayCommand, which occurs when any player says anything on the default chat window. If the message starts with /me, a magic effect command is dispatched.

public class DisplayMagicEffectHandler : CommandHandler<PlayerSayCommand>
{
    public override Promise Handle(Func<Promise> next, PlayerSayCommand command)
    {
        if (command.Message.StartsWith("/me ") && int.TryParse(command.Message.Substring(4), out int id) && id >= 1 && id <= 70)
        {
            return Context.AddCommand(new ShowMagicEffectCommand(command.Player, (MagicEffectType)id) );
        }

        return next();
    }
}