Regular Expression Validation Class

Introduction

I often find myself re-writing the same bits of code for various projects. I know the whole point of object oriented design is to avoid this so I made myself this little Regex validation class. I find it useful for validating inputs and database values, etc. Hope you find it useful as well. Any pointers on how to extend it or better regular expressions will be gladly accepted.

The Code

using System;
using System.Collections;
using System.Text.RegularExpressions;
namespace Company.Validation
{
    public enum ValidationTypes
    {
	PositiveDecimal,
	Decimal,
	PositiveNonDecimal,
	NonDecimal,
	DatesDDMMYYYY,
	DatesDDMMYY,
	DatesDD_MMM_YYYY,
	Email,
	IPAddress,
	URL
    }

    /// <summary>
    /// To Validate strings against Regular Expression strings.
    /// </summary>
    public class RegExValidate
    {
        static ArrayList RegexStrings;
        static RegExValidate()
        {
            RegexStrings = new ArrayList();
	   //PositiveNumber
	   RegexStrings.Insert( (int)ValidationTypes.PositiveDecimal, 
		@"^[0-9][0-9]*(\.[0-9]*)?$");
	   //Number
	   RegexStrings.Insert( (int)ValidationTypes.Decimal, 
	  	@"^(\+|-)?[0-9][0-9]*(\.[0-9]*)?$");
	   //PositiveNonDecimal
	   RegexStrings.Insert( (int)ValidationTypes.PositiveNonDecimal, 
		@"^[0-9][0-9]*$");
	   //NonDecimal
	   RegexStrings.Insert( (int)ValidationTypes.NonDecimal, 
	 	@"^(\+|-)?[0-9][0-9]*(\.[0-9]*)?$");
	   //Dates(DD/MM/YYYY)
	   RegexStrings.Insert( (int)ValidationTypes.DatesDDMMYYYY, 
		@"((0[1-9]|[12][0-9]|3[01]))[/|-](0[1-9]|1[0-2])
		[/|-]((?:\d{4}|\d{2}))");
	   //Dates(DD/MM/YY)
	   RegexStrings.Insert( (int)ValidationTypes.DatesDDMMYY, 
		@"((0[1-9]|[12][0-9]|3[01]))[/|-](0[1-9]|1[0-2])[/|-]((?:\d{2}))");
	   //Dates(DD MMM YYYY)
	   RegexStrings.Insert( (int)ValidationTypes.DatesDD_MMM_YYYY, 
	 	@"^((31(?!\ (Feb(ruary)?|Apr(il)?|June?|
		(Sep(?=\b|t)t?|Nov)(ember)?)))|
	 	((30|29)(?!\ Feb(ruary)?))|(29(?=\ 
		Feb(ruary)?\ (((1[6-9]|[2-9]\d)(0[48]|
		[2468][048]|[13579][26])|((16|[2468][048]|
		[3579][26])00)))))|(0?[1-9])|1\d|2[0-8])\ 
		(Jan(uary)?|Feb(ruary)?|Ma(r(ch)?|y)|Apr(il)?|
		Ju((ly?)|(ne?))|Aug(ust)?|
		Oct(ober)?|(Sep(?=\b|t)t?|Nov|Dec)(ember)?)\ 
		((1[6-9]|[2-9]\d)\d{2})");
	  //Email
	  RegexStrings.Insert( (int)ValidationTypes.Email, 
		@"([a-zA-Z0-9_\-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|
		(([a-zA-Z0-9\-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})");
	  //IPAddress
	  RegexStrings.Insert( (int)ValidationTypes.IPAddress, 
	 	@"(?<First>2[0-4]\d|25[0-5]|[01]?\d\d?)\.(?<Second>
		2[0-4]\d|25[0-5]|[01]?\d\d?)\.(?<Third>
		2[0-4]\d|25[0-5]|[01]?\d\d?)\.
		(?<Fourth>2[0-4]\d|25[0-5]|[01]?\d\d?)");
	  //URL
	  RegexStrings.Insert( (int)ValidationTypes.URL, 
		@"(?<protocol />\w+):\/\/(?<Domain>[\w.]+\/?)\S*");
        }
		
        /// <summary>
        /// Method returns true if unknown string matches the 
        /// regular expression defined by type
        /// </summary>
        /// <param name="type">ValidationTypes enum</param>
        /// <param name="unknown">String to validate</param>
        /// <returns>True if string validates</returns>
        public static bool Process(ValidationTypes type,string unknown)
        {
	   string test = RegexStrings[(int)type].ToString();
	   // Create a new Regex object.
	   Regex r = new Regex(RegexStrings[(int)type].ToString());
	   // Find a single match in the string.
	   Match m = r.Match(unknown);
	   return m.Success;
        }
    }
}

So it's used something like this.
You call the static method Process with the Validation Type you require and a string value of the object you are trying to validate.
This returns true if the string value is of that type and false if it's not.
For more stuff, see www.chemlock.co.uk.

History

• 14^th June, 2006: Initial post

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)