<?php
/**
 * Simple class to validate form input.
 */
class formValidator
{
	/**
	* Check wether a value is alpha-numeric, if it consists only of
	* characters.
	*
	* @param mixed $value
	* @return boolean
	*/
	public function isAlpha($value)
	{
		return ctype_alpha($value);
	}
  
	/**
	 * Check wether a value is numeric, if it consists only of
	 * numbers.
	 *
	 * @param mixed $value
	 * @return boolean
	 */
	public function isNum($value)
	{
		return ctype_digit($value);
	}
	
	/**
	 * A simple e-mail address validation checker, to see if the
	 * entered e-mail address is correct.
	 *
	 * @param string $value
	 * @return boolean
	 */
	public function isEmail($value)
	{
		$valid = false;
		$match = array();
		$pattern = "/^[a-zA-Z0-9\-\_\.]+\@[a-z0-9\-\_\.]+\.[a-z]{2,5}$/";
		preg_match($pattern, $value, $match);
		if (key_exists(0, $match) && strcmp($match[0], $value) === 0) {
			$valid = true;
		}
		return $valid;
	}
	
	/**
	 * Check wether a sumitted text is between a minimum length and
	 * a maximum length. Defaults are minimum 2 and maximum 50 chars.
	 *
	 * @param mixed $value
	 * @param int $min
	 * @param int $max
	 * @return boolean
	 */
	public function isBetween($value, $min = 2, $max = 50)
	{
		return strlen($value) >= $min && strlen($value) <= $max ? true : false;
	}
	
}

/*
// Example script to see it's functionality
$fv = new formValidator();
echo $fv->isAlpha("Lorum");
echo $fv->isNum("123");
echo $fv->isBetween("We ar champions!");
echo $fv->isEmail("john_123.doe@sub-domain.example.com");
*/