PHP Form Validation

Using the validation script:

Example:

Form:

 <form id="cefiform" name="cefiform" action="<?php echo(htmlentities($_SERVER["PHP_SELF"]));?>" method="post" accept-charset="UTF-8">
   User Name: <input type="text" id="username" name="username" value="<?php if(isset($_POST["username"])) echo($_POST["username"]);?>">
  First Name: <input type="text" id="firstname" name="firstname" value="<?php if(isset($_POST["firstname"])) echo($_POST["firstname"]);?>">
   Last Name: <input type="text" id="lastname" name="lastname" value="<?php if(isset($_POST["lastname"])) echo($_POST["lastname"]);?>">
      E-Mail: <input type="text" id="email" name="email" value="<?php if(isset($_POST["email"])) echo($_POST["email"]);?>">
      Gender: <input type="radio" id="male" name="gender"<?php if(isset($_POST["gender"]) && ($_POST["gender"] == "male")) echo(' checked="checked"');?> value="male"><label for="male">Male</label>
              <input type="radio" id="female" name="gender"<?php if(isset($_POST["gender"]) && ($_POST["gender"] == "female")) echo(' checked="checked"');?> value="female"><label for="female">Female</label>
 </form>

PHP Script:

 if(isset($_POST))
 {
  // Form posted, perform validation tests.
  // Create validator object
  $validator = new Validator();
  // Move $_POST values to validator source
  $validator->addSource($_POST);
  // Trim whitespace from both ends of validator source
  $validator->trimSource();
  // Add validation rules

  if($validator->isFormValid())
  {
   // Data validated and sanitized, now return data from the sanitized source
   $_POST = $validator->returnSource();
   // Continue with processing and/or database operations
  }
 }

Custom Validations:

A custom validation function must return true or false.

Format:

$validator->addValidation('Function Name', 'Element Name', 'Error Message'[, array(Arg1[, Arg2, ...])]);