using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Script.Serialization;
using System.Text;
using System.Text.RegularExpressions;
using System.Net;
using System.Globalization;
using System.Security.Cryptography;
namespace WeBlog {
public static class Utils {
public static double CalculateRating(int raters, double rating, double newRating) {
double calcRating = ((rating * raters) + newRating) / (raters + 1);
calcRating = Math.Floor((calcRating * 2) + .5) / 2;
return calcRating;
}
public static string GetMD5Hash(string input) {
if (String.IsNullOrWhiteSpace(input))
return String.Empty;
// step 1, calculate MD5 hash from input
MD5 md5 = System.Security.Cryptography.MD5.Create();
byte[] inputBytes = System.Text.Encoding.ASCII.GetBytes(input);
byte[] hash = md5.ComputeHash(inputBytes);
// step 2, convert byte array to hex string
StringBuilder sb = new StringBuilder();
for (int i = 0; i < hash.Length; i++) {
sb.Append(hash[i].ToString("x2"));
}
return sb.ToString();
}
public static string GetSummary(string html, int length ) {
string text = Utils.StripHtml(html);
if (text.Length > length) {
text = text.Substring(0, length) + " ...";
text = "\"" + text.Trim() + "\"";
}
return text;
}
public static string GetSHA256Hash(string input) {
byte[] data = Encoding.UTF8.GetBytes(input);
using (HashAlgorithm sha = new SHA256Managed()) {
byte[] encryptedBytes = sha.TransformFinalBlock(data, 0, data.Length);
return Convert.ToBase64String(sha.Hash);
}
}
public static string RemoveIllegalCharacters(string text) {
if (string.IsNullOrEmpty(text))
return text;
text = text.Replace(":", string.Empty);
text = text.Replace("/", string.Empty);
text = text.Replace("?", string.Empty);
text = text.Replace("#", string.Empty);
text = text.Replace("[", string.Empty);
text = text.Replace("]", string.Empty);
text = text.Replace("@", string.Empty);
text = text.Replace("*", string.Empty);
text = text.Replace(".", string.Empty);
text = text.Replace(",", string.Empty);
text = text.Replace("\"", string.Empty);
text = text.Replace("&", string.Empty);
text = text.Replace("'", string.Empty);
text = text.Replace(" ", "-");
text = RemoveDiacritics(text);
text = RemoveExtraHyphen(text);
return HttpUtility.UrlEncode(text).Replace("%", string.Empty);
}
private static string RemoveExtraHyphen(string text) {
if (text.Contains("--")) {
text = text.Replace("--", "-");
return RemoveExtraHyphen(text);
}
return text;
}
private static String RemoveDiacritics(string text) {
String normalized = text.Normalize(NormalizationForm.FormD);
StringBuilder sb = new StringBuilder();
for (int i = 0; i < normalized.Length; i++) {
Char c = normalized[i];
if (CharUnicodeInfo.GetUnicodeCategory(c) != UnicodeCategory.NonSpacingMark)
sb.Append(c);
}
return sb.ToString();
}
private static Regex _Regex = new Regex("<[^>]*>", RegexOptions.Compiled);
/// <summary>
/// Removes all HTML tags from a given string
/// </summary>
public static string StripHtml(string html) {
if (string.IsNullOrEmpty(html))
return string.Empty;
return _Regex.Replace(html, string.Empty);
}
public static event EventHandler<EventArgs> OnLog;
public static void Log(object message)
{
if (OnLog != null)
{
OnLog(message, new EventArgs());
}
}
public static void Log(string methodName, Exception ex)
{
Log(String.Format("{0}: {1}", methodName, ex.Message));
}
}
}
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