Code First: A Practical Case

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web;
using System.IO;

namespace Xah.MediaCatalogerLib
{
    public static class StringExtensions
    {
        public static string DecodeHtml(this string str)
        {
            return HttpUtility.HtmlDecode(str);
        }

        public static string EncodeHtml(this string str)
        {
            return HttpUtility.HtmlEncode(str);
        }

        public static string EncodeANSIUrl(this string str)
        {
            return HttpUtility.UrlEncode(str, Encoding.Default);
        }

        public static string FindFirstBetween(this string str, string begin, string end)
        {
            string[] matches = FindBetween(str, begin, end, true, false);
            return (matches.Length > 0) ? matches[0] : String.Empty;
        }

        public static string FindLastBetween(this string str, string begin, string end)
        {
            string[] matches = FindBetween(str, begin, end, false, false);
            return (matches.Length > 0) ? matches[matches.Length - 1] : String.Empty;
        }

        public static string[] FindBetween(this string str, string begin, string end)
        {
            return FindBetween(str, begin, end, false, false);
        }

        public static string[] FindBetweenTrim(this string str, string begin, string end)
        {
            return FindBetween(str, begin, end, false, true);
        }

        private static string[] FindBetween(this string str, string begin, string end, bool first, bool trim)
        {
            List<string> matches = new List<string>();

            int start = 0;
            while ((start = str.IndexOf(begin, start)) >= 0)
            {
                start += begin.Length;
                int stop = str.IndexOf(end, start);
                if (stop >= start)
                {
                    string match = str.Substring(start, stop - start);
                    if (trim) match = match.Trim();
                    matches.Add(match);
                }
                else
                {
                    stop = str.Length - end.Length;
                }

                start = stop + end.Length;

                if (first) break;
            }

            return matches.ToArray();
        }

        public static string RemoveBetween(this string str, string begin, string end)
        {
            string result = str;
            
            int start = 0;
            while ((start = result.IndexOf(begin, start)) >= 0)
            {
                int stop = result.IndexOf(end, start + begin.Length);
                if (stop == -1) break;

                result = result.Remove(start, stop + end.Length - start);
            }

            return result;
        }

        public static string UntilMatch(this string str, string match)
        {
            int stop = str.IndexOf(match);
            if (stop < 0) return str;

            return str.Substring(0, stop);
        }

        public static string FromMatch(this string str, string match)
        {
            int start = str.IndexOf(match);
            if (start < 0) return String.Empty;

            start += match.Length;
            return str.Substring(start, str.Length - start);
        }

        public static bool Contains(this string str, string match, StringComparison comparison)
        {
            return str.IndexOf(match, comparison) >= 0;
        }

        public static long SafeConvertToInt64(this string str)
        {
            long converted = 0;
            try
            {
                converted = Convert.ToInt64(str);
            }
            catch { }

            return converted;
        }

        public static int SafeConvertToInt32(this string str)
        {
            int converted = 0;
            try
            {
                converted = Convert.ToInt32(str);
            }
            catch { }

            return converted;
        }

        public static short SafeConvertToInt16(this string str)
        {
            short converted = 0;
            try
            {
                converted = Convert.ToInt16(str);
            }
            catch { }

            return converted;
        }

        public static byte SafeConvertToByte(this string str)
        {
            byte converted = 0;
            try
            {
                converted = Convert.ToByte(str);
            }
            catch { }

            return converted;
        }

        public static float SafeConvertToSingle(this string str)
        {
            float converted = 0;
            try
            {
                converted = Convert.ToSingle(str.Replace(',','.'), System.Globalization.CultureInfo.InvariantCulture);
            }
            catch { }

            return converted;
        }

        public static string NormalizeNewLines(this string str)
        {
            StringReader sr = new StringReader(str);
            StringWriter sw = new StringWriter();
            
            string line;
            while ((line = sr.ReadLine()) != null)
                sw.WriteLine(line);

            return sw.ToString();
        }

        public static string RemoveNewLines(this string str, bool trim)
        {
            StringReader sr = new StringReader(str);
            StringWriter sw = new StringWriter();

            string line;
            while ((line = sr.ReadLine()) != null)
                sw.Write(trim ? line.Trim() : line);

            return sw.ToString();
        }
    }
}