Validation Class

Here is a class I've had in my library for a while. I've seen quite a few posts asking about validation, so I figured id share this. It's commented well, so read them before you ask how to use it. As I write new validations, I will update this thread. If you have a validation regex that is not included in this class, feel free to post it and I will give you credit in the comments. If you need a validation not included that you would like to see, please request it below and I will add it.

<?php


/**

 * @author John Ciacia

 * @copyright 2008

 */


class Validator

{

    const ALPHA = 1;

    const NUMBER = 2;

    const ALPHNUM = 3;

    const UPPER = 4;

    const LOWER = 5;


    function __construct()

    {


    }


    //This function validates a string of a particular type.

    //You can either pass in a number (1-5) or its defininion

    //as defined above. If the string is of the valid type

    //this function will return true. If the string is not

    //of the valid type, it will return false.

    static public function valid_string($input, $type)

    {

        switch ($type) {

                //such a string can only contain alphabetical characters

            case ALPHA:

                if (preg_match('/^[a-z]+$/i', $input))

                    return true;

                return false;

                break;


                //such a string can only contain numbers

            case NUMBER:

                if (preg_match('/^\d+$/', $input))

                    return true;

                return false;

                break;


                //such a string can only contain numbers and alphabetical characters

            case ALPHNUM:

                if (preg_match('/^[a-zA-Z0-9]+$/i', $input))

                    return true;

                return false;

                break;


                //such a string can only contain uppercase characters

            case UPPER:

                if (preg_match('/[A-Z]/', $input) && !preg_match('/[a-z]/', $input))

                    return true;

                return false;

                break;


                //such a string can only contain lowercase characters

            case LOWER:

                if (!preg_match('/[A-Z]/', $input) && preg_match('/[a-z]/', $input))

                    return true;

                return false;

                break;


        }

    }


    //This function checks whether an email address is valid. It is

    //not perfect as it does not account for .museum email addresses

    //however this tradeoff is preferable to the other downsides

    //of allowing it.

    static public function valid_email($input)

    {

        if (!eregi("^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}$", $input)) {

            return false;

        }

        return true;

    }


    //This function checks whether a string is within certain size constraints.

    //For example, the required length of a password might be 5 characters. Setting

    //$min to 5 will require the password to be larger than or equal to five

    //characters. If not, it will display an error message. If either $max

    //or $min is set to 0, length checking is ignored on that constraing. The max

    //constraint might be set on a contact form, where the text entered should

    //not be any longer than 250 characters.

    static public function valid_size($input, $min = 0, $max = 0)

    {

        //check the minimum size constraints

        //in this case: the string needs to be longer

        if (strlen($input) < $min) {

            return false;

        }


        //check the maximum size constraints

        //in this case: the string is too long

        if (($max != 0) && (strlen($input) > $max)) {

            return false;

        }


        return true;

    }


}


?>

Don't understand regular expressions? This will get you started.

Edited by John, 03 September 2008 - 03:42 PM.