using System;
using System.Collections.Generic;
using System.Text;

namespace IvyBus
{
    [AttributeUsage(AttributeTargets.Method,AllowMultiple = true)]
    public sealed class IvyBindingAttribute : Attribute
    {
        private string expression;
        private string[] args;

        // translate part of expression to object property
        public string GetExpression(object obj)
        {
            if (obj == null) return string.Format(expression);
            object[] values = new object[args.Length];
            for (int i = 0; i < args.Length; i++)
            {
                values[i] = obj.GetType().GetProperty(args[i]).GetValue(obj,null);
            }
            return string.Format(expression,values);
        }

        public IvyBindingAttribute(string expression, params string[] args)
        {
            this.expression = expression;
            this.args = args;
        }
    }
}