Form with one to many relation

Question

In my database I have 2 tables:

Course table:

• id (PK)
• name (varchar)
• description (text)

Session table:

• id (PK)
• date (datetime)
• course_id (FK to id from course table)

The buildForm function in my SessionType looks like this:

public function buildForm(FormBuilderInterface $builder, array $options)
{
    $builder
        ->add('date');
}

The buildForm function in my CourseType looks like this:

$builder
    ->add('name')
    ->add('description')
    ->add('foreknowledge')
    ->add('teacher')
    ->add('sessions', CollectionType::class, array(
        'entry_type' => SessionType::class,
        'entry_options' => array('label' => false),
        'allow_add' => true,
        'by_reference' => false,
        'allow_delete' => true,
    ))

My form in my twig template looks like this:

{{ form_start(form) }}
    {{ form_widget(form) }}

    <input type="submit" value="Create" />
{{ form_end(form) }}

But nothing is shown under "Sessions". I would like to have the possibility to create multiple sessions under my course. Is there an easy way to do this?

UPDATE:

When I try to save my course and do a dump just before I save I get this:

My sessions are saved, but they are not linked to course. How does this come?

Answer 1

That is possible and you are missing some javascript, it is very well documented here .

Instead of copy-pasting from that documentation page here, you can read it and ask if you need any help with it.