DynamicHtml.cs

using System;
using System.Collections.Generic;
using System.Dynamic;
using System.Linq;
using System.Text;

namespace CSharpFourScratch
{
	internal class Program
	{
		private static void Main()
		{
			var table = new HtmlTag
			{
				Name = "table",
				Children =
					{
						new HtmlTag
						{
							Name = "tr",
							Children =
								{
									new HtmlTag {Name = "td"},
									new HtmlTag {Name = "td"}
								}
						}
					}
			}.Dynamic.Attr(
				border: 1,
				width: 360,
				height: 180,
				padding: "5px"
				);
			Console.WriteLine(table.ToString());
			Console.ReadLine();
		}
	}

	internal class DynamicHtmlTag : DynamicObject
	{
		private readonly HtmlTag _tag;

		public DynamicHtmlTag(HtmlTag tag)
		{
			_tag = tag;
		}

		public override bool TryInvokeMember(InvokeMemberBinder binder, object[] args, out object result)
		{
			if (binder.Name == "Attr")
			{
				IEnumerable<Tuple<string, string>> pairs = binder.
					CallInfo
					.ArgumentNames
					.Zip(args,
						 (x, y) =>
						 new Tuple<string, string>
							 (x, y.ToString()));
				foreach (var pair in pairs)
					_tag[pair.Item1] = pair.Item2;
				result = this;
				return true;
			}
			return base.TryInvokeMember(binder, args, out result);
		}
		public override string ToString()
		{
			return _tag.ToString();
		}
		
	}

	internal class HtmlTag
	{
		private dynamic _dynamic;
		public dynamic Dynamic { get { return _dynamic ?? (_dynamic = new DynamicHtmlTag(this)); } }

		private readonly IDictionary<string, string> _attributes = new Dictionary<string, string>();

		private IList<HtmlTag> _children = new List<HtmlTag>();
		public string Name { get; set; }

		public string this[string attr]
		{
			get { return _attributes[attr]; }
			set { _attributes[attr] = value; }
		}

		public IList<HtmlTag> Children
		{
			get { return _children; }
			set { _children = value; }
		}

		public override string ToString()
		{
			var builder = new StringBuilder();
			builder.AppendFormat("<{0} ", Name);
			foreach (var attribute in _attributes)
				builder.AppendFormat("{0}=\"{1}\" ", attribute.Key, attribute.Value);
			if (_children.Any())
			{
				builder.AppendLine(">");
				foreach (HtmlTag child in Children)
					builder.AppendFormat("\t{0}", child);
				builder.AppendFormat("</{0}>\n", Name);
			}
			else
				builder.AppendLine("/>");
			return builder.ToString();
		}
	}
}