NameValuePairList.cs

// HtmlAgilityPack V1.0 - Simon Mourier <simon underscore mourier at hotmail dot com>
using System;
using System.Collections;
using System.Collections.Generic;

namespace HtmlAgilityPack
{
	internal class NameValuePairList
	{
		#region Fields

		internal readonly string Text;
		private List<KeyValuePair<string, string>> _allPairs;
		private Dictionary<string,List<KeyValuePair<string,string>>> _pairsWithName;

		#endregion

		#region Constructors

		internal NameValuePairList() :
			this(null)
		{
		}

		internal NameValuePairList(string text)
		{
			Text = text;
			_allPairs = new List<KeyValuePair<string, string>>();
			_pairsWithName = new Dictionary<string, List<KeyValuePair<string, string>>>();

			Parse(text);
		}

		#endregion

		#region Internal Methods

		internal static string GetNameValuePairsValue(string text, string name)
		{
			NameValuePairList l = new NameValuePairList(text);
			return l.GetNameValuePairValue(name);
		}

		internal List<KeyValuePair<string,string>> GetNameValuePairs(string name)
		{
			if (name == null)
				return _allPairs;
			return _pairsWithName.ContainsKey(name) ? _pairsWithName[name] : new List<KeyValuePair<string,string>>();
		}

		internal string GetNameValuePairValue(string name)
		{
			if (name == null)
				throw new ArgumentNullException();
			List<KeyValuePair<string,string>> al = GetNameValuePairs(name);
			if (al.Count==0)
				return string.Empty;

			// return first item
			 return al[0].Value.Trim();
		}

		#endregion

		#region Private Methods

		private void Parse(string text)
		{
			_allPairs.Clear();
			_pairsWithName.Clear();
			if (text == null)
				return;

			string[] p = text.Split(';');
			foreach (string pv in p)
			{
				if (pv.Length == 0)
					continue;
				string[] onep = pv.Split(new[] {'='}, 2);
				if (onep.Length==0)
					continue;
				KeyValuePair<string, string> nvp = new KeyValuePair<string, string>(onep[0].Trim().ToLower(),
																					onep.Length < 2 ? "" : onep[1]);

				_allPairs.Add(nvp);

				// index by name
				List<KeyValuePair<string, string>> al;
				if (!_pairsWithName.ContainsKey(nvp.Key))
				{
					al = new List<KeyValuePair<string, string>>();
					_pairsWithName[nvp.Key] = al;
				}
				else
					al = _pairsWithName[nvp.Key];

				al.Add(nvp);
			}
		}

		#endregion
	}
}