How to render dynamic symfony form?

Member

by lew , in category: PHP Frameworks , 2 months ago

How to render dynamic symfony form?

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1 answer

Member

by brandy , 2 months ago

@lew 

To render a dynamic Symfony form, you can follow these steps:

  1. Create a Form Type: Start by creating a form type class that extends the AbstractType class. Inside this class, define the form fields and their options.
  2. Add dynamic form fields: To add dynamic form fields, you can make use of the FormEvents::PRE_SET_DATA event listener. In the event listener, modify the form based on the data passed to it. You can add or remove form fields dynamically.
  3. Bind the form type to a form: In your controller, create an instance of the form type and pass it to the createForm method along with the data. This will create a form object that you can render in your template.
  4. Render the form in the template: In your template file, you can render the form by using the form_start(form) and form_end(form) functions. Use the form_widget(form.fieldName) function to render individual form fields.


Here's an example that demonstrates these steps:

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// Form Type
use SymfonyComponentFormAbstractType;
use SymfonyComponentFormExtensionCoreTypeTextType;
use SymfonyComponentFormFormBuilderInterface;
use SymfonyComponentFormFormEvent;
use SymfonyComponentFormFormEvents;

class MyFormType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder
            ->add('name', TextType::class)
            ->addEventListener(FormEvents::PRE_SET_DATA, function (FormEvent $event) {
                $form = $event->getForm();
                $data = $event->getData();
                
                if ($data && $data->getFieldType() === 'dynamic') {
                    $form->add('dynamicField', TextType::class);
                }
            });
    }
}


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// Controller
use SymfonyBundleFrameworkBundleControllerAbstractController;
use SymfonyComponentHttpFoundationRequest;

class MyController extends AbstractController
{
    public function index(Request $request)
    {
        $data = new MyData();
        $form = $this->createForm(MyFormType::class, $data);
        $form->handleRequest($request);

        if ($form->isSubmitted() && $form->isValid()) {
            // Process form data
        }

        return $this->render('my-template.html.twig', [
            'form' => $form->createView(),
        ]);
    }
}


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{# my-template.html.twig #}
{{ form_start(form) }}
{{ form_widget(form.name) }}
{{ form_widget(form.dynamicField) }}
{{ form_end(form) }}


In the example above, the "dynamicField" is added to the form only when the provided data has a "fieldType" attribute set to "dynamic".