Symfony 2，在实体上使用ChoiceType的createFormBuilder，choice_label是int

Question

I have a little problem with Symfony 2 and the form builder. I want to create a ChoiceType field based on Doctrine findAll result.

My choices are entities array, but on the choice_label function, the first variable is int !

I put a little code for explain :

    $categories = $categoryRepository->findAll();

    foreach ($categories as $value) {
        echo "category name : ".$value->getName()."<br/>";
    }
    /* Result :
        category name : First
        category name : Second
     */        

    $form = $this->createFormBuilder($dance)
            ->add('name', TextType::class, array('label' => 'Nom de la dance'))
            ->add('description', TextareaType::class, array('label' => 'Description'))
            ->add('creationDate', DateTimeType::class, array('label' => 'Date de création'))
            ->add('category', ChoiceType::class, [
                'choices' => $categories,
                'choice_label' => function($category, $key, $index) {
                    var_dump($category);
                    // Result : int(0) 
                    return $category->getName();
                    // Exception !
                },
                'choice_attr' => function($category, $key, $index) {
                    return ['class' => $category->getId()];
                },
            ])
            ->add('save', SubmitType::class, array('label' => 'Sauvegarder'))
            ->getForm();

Of course, I have a Fatal error: Call to a member function getName() on integer ...

Someone can help me on this problem ?

Thank you !

Answer 1

If you're using an older version than Symfony 2.7, you can not simply pass an array of objects to the choices option. This is only supported in Symfony >=2.7. If you want to do this in Symfony 2.7 or 2.8, you have to activate the choices_as_values option :

'choices_as_values' => true

By default, in Symfony 2.x choices is built the other way around: the keys of the array become the value and the value of they array becomes the label . So, you'll get 0 for the first element in your array. :)

Alternatively, you may want to use the EntityType class instead of ChoiceType . It will pass the actual object to the function in any case.

Furthermore, if you want to specify a property of your entity (or a referenced entity) as your label, you can also use property paths :

'choice_label' => 'name'