Conditional validator in Symfony, another approach

Carlos Barros — Wed, 05 Nov 2008 12:10:27 +0000

Today morning I was reading the Symfony blog, more specifically A week of symfony #96 and then I came across a tutorial talking about conditional validators.This is very usefull, I find myself using this technique very often, so I decided to write about another techinique I use sometimes to implement a conditional validation, but for a different scenario. Imagine the following: you have a contact form where the users specify how they want to be contacted, email or phone, throught a select box. Then you have two input boxes where the users can enter both email and phone. If the user opts to be contacted via email, email field becomes mandatory and phone number optional, and the opposite happens if the user opts to be contacted via phone. So, how to implement such a form in symfony?

A normal form would look like this:

lib/form/ContactForm.class.php:

class ContactForm extends sfForm
{
  public function configure()
  {
    $this->setWidgets(array(
      'method'	=> new sfWidgetFormSelect(array('choices'=>array('phone'=>'Phone','email'=>'Email'))),
      'email'	=> new sfWidgetFormInput(),
      'phone'	=> new sfWidgetFormInput(),
      'msg'	=> new sfWidgetFormTextarea(),
    ));
 
    $this->setValidators(array(
      'method'	=> new sfValidatorChoice(array(
			'choices'=>array('phone','email'),
		)),
      'email'	=> new sfValidatorEmail(array(
			'required'=>true,
		),array(
			'required'=>'Please enter your email address',
			'invalid'=>'Invalid email address'
		)),
      'phone'	=> new sfValidatorString(array(
			'required'=>true,
		),array(
			'required'=>'Please enter your phone number',
		)),
      'msg'	=> new sfValidatorString(array(
			'required'=>true,
		),array(
			'required'=>'Please enter your message',
		)),
    ));
 
    $this->widgetSchema->setLabels(array(
	'email'		=> 'Email:',
	'phone'		=> 'Phone:',
	'method'	=> 'Contact type:',
	'msg'		=> 'Message:',
    ));
 
    $this->widgetSchema->setNameFormat('contact[%s]');
    $this->errorSchema = new sfValidatorErrorSchema($this->validatorSchema);
  }

The problem with this form is the fact that both phone and email are ALWAYS mandatory, regardless of the value of method. So, what we need is a way to intercept method’s value and update validators. So, what we need is intercept the bind method in order to check method’s value:

lib/form/ContactForm.class.php:

  public function bind(array $taintedValues = null, array $taintedFiles = null)
  {
    if(@$taintedValues["method"] == 'phone') $this->validatorSchema["email"]->setOption('required',false);
    else $this->validatorSchema["phone"]->setOption('required',false);
 
    return parent::bind($taintedValues,$taintedFiles);
  }

As can be seen, we create our own bind method, overriding parent one, and before calling the actual bind method, we inspect the values sent by the user and if method is phone, we remove the required option from email validator, otherwise we remove the required option from phone validator and finally call parent method.

The resulting form can be seen here!

blog.barros.ws » conditional validator

Conditional validator in Symfony, another approach