Parsing ASPX and Other Mixed Content

////////////////////////////////////////////////////////////////////////////////
// MixedContent Sample - Free to use
// � Copyright 2007, Rudi Breedenraedt
////////////////////////////////////////////////////////////////////////////////
using System;
using System.Collections.Generic;
using System.Text.RegularExpressions;

namespace CodeProject.MixedContentSample.Parser
{
	/// <summary>
	/// Represents a file with mixed content.
	/// </summary>
	public class MixedContentFile
	{
		private string content;
		private List<ContentPart> parts = new List<ContentPart>();

		/// <summary>
		/// Constructs a MixedContentFile for the given file having given conetent.
		/// </summary>
		public MixedContentFile(string content, int initialContentType)
		{
			// Set properties:
			this.content = content;

			// Seed the parts list:
			this.parts.Add(new ContentPart(this, initialContentType, 0, content.Length, null));
		}

		/// <summary>
		/// Content of the file.
		/// </summary>
		public string Content
		{
			get { return this.content; }
		}

		/// <summary>
		/// List of parts the file is made of.
		/// </summary>
		public List<ContentPart> Parts
		{
			get { return this.parts; }
		}

		/// <summary>
		/// Applies a parser regular expression to identifiy types of content.
		/// </summary>
		/// <param name="typeToSearch">The content type to search in.</param>
		/// <param name="typeToSearchFor">The content type of the parts matching the given regular expression.</param>
		/// <param name="expressionToSearchFor">The regular expression to use to match content parts.</param>
		public void ApplyParserRegex(int typeToSearch, int typeToSearchFor, Regex expressionToSearchFor)
		{
			List<ContentPart> result = new List<ContentPart>();
			foreach (ContentPart section in this.parts)
			{
				if (section.Type == typeToSearch)
				{
					int pos = 0;
					foreach (Match match in expressionToSearchFor.Matches(section.Content))
					{
						if (pos < match.Index)
						{
							result.Add(new ContentPart(section.File, section.Type, section.Offset + pos, match.Index - pos, section.Match));
						}
						result.Add(new ContentPart(section.File, typeToSearchFor, section.Offset + match.Index, match.Length, match));
						pos = match.Index + match.Length;
					}
					if (pos < section.Length)
					{
						result.Add(new ContentPart(section.File, section.Type, section.Offset + pos, section.Length - pos, section.Match));
					}
				}
				else
				{
					result.Add(section);
				}
			}

			// Perform iteration substitution:
			this.parts = result;
		}
	}
}