Regular Expression Validation Class
A class that allows easy validation of variables via Regular Expressions
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,
@"(? \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
- 14th June, 2006: Initial post