cs11dotnet7/vscode/Chapter07/SharedLibrary/StringExtensions.cs

using System.Text.RegularExpressions;

namespace Packt.Shared
{
  public static class StringExtensions
  {
    public static bool IsValidXmlTag(this string input)
    {
      return Regex.IsMatch(input,
        @"^<([a-z]+)([^<]+)*(?:>(.*)<\/\1>|\s+\/>)$");
    }

    public static bool IsValidPassword(this string input)
    {
      // minimum of eight valid characters
      return Regex.IsMatch(input, "^[a-zA-Z0-9_-]{8,}$");
    }

    public static bool IsValidHex(this string input)
    {
      // three or six valid hex number characters
      return Regex.IsMatch(input,
        "^#?([a-fA-F0-9]{3}|[a-fA-F0-9]{6})$");
    }
  }
}