Making PHP Forms Object-Oriented

Making PHP Forms Object-Oriented - Example of a Form
(Page 6 of 7 )

Now we are equipped for the final touch: building a small example. I will demonstrate creation of the first page of a wizard that should collect some information. Let's say, about a subscription to some internet resource. As the first step, the user must enter the username he/she is going to use and a valid email address, then select the type of the registration. Based on the registration type the user chooses, the wizard should proceed to a corresponding screen.

Before the wizard can proceed, it validates values that the user enters. I will not build the forms for the second step. There's not much interesting to do without introducing additional input classes; and I would still like the article's subject to stay on the same topic.

<?php

  define('MinNameLength', 5);
  
  class RegForm01 extends FormProcessor {
    
    function CustomCheck() {
      if (strlen($this->Values['Name']) < MinNameLength)
        $this->Errors['Name'] =  
            'Username should contain at least ' . MinNameLength . ' symbols';
        
      if ($this->Values['Email']) {
        if (!eregi('^[-!#$%&\'*+\\./0-9=?A-Z^_\`a-z{|}~]+
            @[-!#$%&\'*+\\/0-9=?A-Z^_\`a-z{|}~]+\.[-!#$%&'*+
            '\\./0-9=?A-Z^_\`a-z{|}~]+$', $this->Values['Email']))
          $this->Errors['Email'] = 'Value entered does not
            appear to be a valid e-mail address';
      } else {
        $this->Errors['Email'] =  
            'E-mail address is required to complete subscription';
      }
    }
    
    function NextWizardPage() {
      //decision about what wizard's screen to load next is made here,
      //based on the submitted values:
      return ($this->Values['PaymentMethod'] ==  
        'P')?'reg_form_free.php':'reg_form_payed.php';
    }
    
    function StoreData() {
      // we will not discuss storing persistent variables in this article.
      // here would normally appear code that updates a database or
      // stores session variables
      STORE_VARIABLE($this->Values['Name']);
    }
    
    function DisplayForm() {
    // I'm not sure you meet a form like this on a real web-site =), but I hope
    // it'll do for the example

?>
<form action="<?php echo $PHP_SELF?>" method="POST">
    Username: <?php new TextInput($this, 'Name', '', 'size="30" maxlength="100"')?>
    <?php $this->ErrorReport('Name')?>

    Email: <?php new TextInput($this, 'Email', '', 'size="30" maxlength="100"')?>
    <?php $this->ErrorReport('Email')?>
    <br><br>
    Subscription type:<br>
    <?php new RadioButtons($this, 'SubscrType', array('P'=>'Preview', 'M'=>'Membership'), 'P')?>
    <?php $this->ErrorReport('SubscrType')?>
    <br>
    <br>
    <?php $this->Additional()?>
    <input type="submit" name="Submit" value="Submit">
</form>
<?php

    }
  }
  
  $form = new RegForm01('RegForm01', 'reg_form01.php');
?>

This code can also be downloaded at the end of this article.
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