How to add global event listener in symfony forms

Question

I want to add event listener to all symfony forms on pre_set_data.

I have service and tag for this { name: kernel.event_listener, event: form.pre_set_data, method: onSetData}

The event listener is registered and I can see it with php app/console debug:event-dispatcher but is is never called.

When I add the event directly to the form using ->addEventListener(FormEvents::PRE_SET_DATA, function(){ ... }) it is working.

How I can add this event listener globally ? to all forms?

Answer 1

A simple way would be to create a form extension that extends the base form type, and register your event listener there:

<?php

namespace AppBundle\Form\Extension;

use Symfony\Component\Form\AbstractTypeExtension;
use Symfony\Component\Form\Extension\Core\Type\FormType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\Form\FormEvents;

class FormTypeExtension extends AbstractTypeExtension
{
    /**
     * @inheritdoc
     */
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder->addEventListener(FormEvents::PRE_SET_DATA, function () {
            // skip...
        });
    }

    /**
     * @inheritdoc
     */
    public function getExtendedType()
    {
        return FormType::class;
    }
}

with:

# config/services.yaml
services:
    # ...

    AppBundle\Form\Extension\FormTypeExtension:
        tags:
            - { name: form.type_extension, extended_type: Symfony\Component\Form\Extension\Core\Type\FormType }