12. The class that supports the validation functionality is called Validate, and it is hosted in a script file called validate.class.php, which looks like this:
<?php
// load error handler and database configuration
require_once ('config.php');
// Class supports AJAX and PHP web form validation
class Validate
{
// stored database connection
private $mMysqli;
// constructor opens database connection
function __construct()
{
$this->mMysqli = new mysqli(DB_HOST, DB_USER, DB_PASSWORD, DB_DATABASE);
}
// destructor closes database connection
function __destruct()
{
$this->mMysqli->close();
}
// supports AJAX validation, verifies a single value
public function ValidateAJAX($inputValue, $fieldID)
{
// check which field is being validated and perform validation
switch($fieldID)
{
// Check if the username is valid
case 'txtUsername':
return $this->validateUserName($inputValue);
break;
// Check if the name is valid
case 'txtName':
return $this->validateName($inputValue);
break;
// Check if a gender was selected
case 'selGender':
return $this->validateGender($inputValue);
break;
// Check if birth month is valid
case 'selBthMonth':
return $this->validateBirthMonth($inputValue);
break;
// Check if birth day is valid
case 'txtBthDay':
return $this->validateBirthDay($inputValue);
break;
// Check if birth year is valid
case 'txtBthYear':
return $this->validateBirthYear($inputValue);
break;
// Check if email is valid
case 'txtEmail':
return $this->validateEmail($inputValue);
break;
// Check if phone is valid
case 'txtPhone':
return $this->validatePhone($inputValue);
break;
// Check if "I have read the terms" checkbox has been checked
case 'chkReadTerms':
return $this->validateReadTerms($inputValue);
break;
}
}
// validates all form fields on form submit
public function ValidatePHP()
{
// error flag, becomes 1 when errors are found.
$errorsExist = 0;
// clears the errors session flag
if (isset($_SESSION['errors']))
unset($_SESSION['errors']);
// By default all fields are considered valid
$_SESSION['errors']['txtUsername'] = 'hidden';
$_SESSION['errors']['txtName'] = 'hidden';
$_SESSION['errors']['selGender'] = 'hidden';
$_SESSION['errors']['selBthMonth'] = 'hidden';
$_SESSION['errors']['txtBthDay'] = 'hidden';
$_SESSION['errors']['txtBthYear'] = 'hidden';
$_SESSION['errors']['txtEmail'] = 'hidden';
$_SESSION['errors']['txtPhone'] = 'hidden';
$_SESSION['errors']['chkReadTerms'] = 'hidden';
// Validate username
if (!$this->validateUserName($_POST['txtUsername']))
{
$_SESSION['errors']['txtUsername'] = 'error';
$errorsExist = 1;
}
// Validate name
if (!$this->validateName($_POST['txtName']))
{
$_SESSION['errors']['txtName'] = 'error';
$errorsExist = 1;
}
// Validate gender
if (!$this->validateGender($_POST['selGender']))
{
$_SESSION['errors']['selGender'] = 'error';
$errorsExist = 1;
}
// Validate birth month
if (!$this->validateBirthMonth($_POST['selBthMonth']))
{
$_SESSION['errors']['selBthMonth'] = 'error';
$errorsExist = 1;
}
// Validate birth day
if (!$this->validateBirthDay($_POST['txtBthDay']))
{
$_SESSION['errors']['txtBthDay'] = 'error';
$errorsExist = 1;
}
// Validate birth year and date
if (!$this->validateBirthYear($_POST['selBthMonth'] . '#' .
$_POST['txtBthDay'] . '#' .
$_POST['txtBthYear']))
{
$_SESSION['errors']['txtBthYear'] = 'error';
$errorsExist = 1;
}
// Validate email
if (!$this->validateEmail($_POST['txtEmail']))
{
$_SESSION['errors']['txtEmail'] = 'error';
$errorsExist = 1;
}
// Validate phone
if (!$this->validatePhone($_POST['txtPhone']))
{
$_SESSION['errors']['txtPhone'] = 'error';
$errorsExist = 1;
}
// Validate read terms
if (!isset($_POST['chkReadTerms']) ||
!$this->validateReadTerms($_POST['chkReadTerms']))
{
$_SESSION['errors']['chkReadTerms'] = 'error';
$_SESSION['values']['chkReadTerms'] = '';
$errorsExist = 1;
}
// If no errors are found, point to a successful validation page
if ($errorsExist == 0)
{
return 'allok.php';
}
else
{
// If errors are found, save current user input
foreach ($_POST as $key => $value)
{
$_SESSION['values'][$key] = $_POST[$key];
}
return 'index.php';
}
}
// validate user name (must be empty, and must not be already registered)
private function validateUserName($value)
{
// trim and escape input value
$value = $this->mMysqli->real_escape_string(trim($value));
// empty user name is not valid
if ($value == null)
return 0; // not valid
// check if the username exists in the database
$query = $this->mMysqli->query('SELECT user_name FROM users ' .
'WHERE user_name="' . $value . '"');
if ($this->mMysqli->affected_rows > 0)
return '0'; // not valid
else
return '1'; // valid
}
// validate name
private function validateName($value)
{
// trim and escape input value
$value = trim($value);
// empty user name is not valid
if ($value)
return 1; // valid
else
return 0; // not valid
}
// validate gender
private function validateGender($value)
{
// user must have a gender
return ($value == '0') ? 0 : 1;
}
// validate birth month
private function validateBirthMonth($value)
{
// month must be non-null, and between 1 and 12
return ($value == '' || $value > 12 || $value < 1) ? 0 : 1;
}
// validate birth day
private function validateBirthDay($value)
{
// day must be non-null, and between 1 and 31
return ($value == '' || $value > 31 || $value < 1) ? 0 : 1;
}
// validate birth year and the whole date
private function validateBirthYear($value)
{
// valid birth year is between 1900 and 2000
// get whole date (mm#dd#yyyy)
$date = explode('#', $value);
// date can't be valid if there is no day, month, or year
if (!$date[0]) return 0;
if (!$date[1] || !is_numeric($date[1])) return 0;
if (!$date[2] || !is_numeric($date[2])) return 0;
// check the date
return (checkdate($date[0], $date[1], $date[2])) ? 1 : 0;
}
// validate email
private function validateEmail($value)
{
// valid email formats: *@*.*, *@*.*.*, *.*@*.*, *.*@*.*.*)
return (!eregi('^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$', $value)) ? 0 : 1;
}
// validate phone
private function validatePhone($value)
{
// valid phone format: ###-###-####
return (!eregi('^[0-9]{3}-*[0-9]{3}-*[0-9]{4}$', $value)) ? 0 : 1;
}
// check the user has read the terms of use
private function validateReadTerms($value)
{
// valid value is 'true'
return ($value == 'true' || $value == 'on') ? 1 : 0;
}
}
?>
13. Test your script by loading http://localhost/ajax/validate/index.php in a web browser.
