Unmapped Form Fields in Symfony

Objective

Use a form class to build out a form to edit an entity.

Add fields to the form to control navigation after submitting the form, for example.

These extra fields don't have equivalents in the entity class. It cannot be used to inspect their values in the submitted form data.

Form Class

class InvoiceType extends AbstractType 
{
	public function buildForm(FormBuilderInterface $builder, array $options) 
	{
		$builder
			->add('number', 'integer', array(
				'label' => 'Invoice Number',
			))
			->add('amount', 'money', array(
				'currency'=> 'USD',
			))
			// ...
			->add('next', 'next_nav_choice', array(
				'label' => 'After saving the invoice go to:',
				'placeholder' => null,
				'required' => false,
				'choices' => array(
					'list' => 'invoice listings',
					'details' => 'view the invoice',
					'add' => 'add another invoice',
					),
				'empty_data' => array('list'),
				'expanded' => true,
				'mapped' => false,
			))
			->add('save', 'submit');
	}