How to detect widget type in Symfony Twig rendering? - symfony

Question

For rendering form rows, I need to detect what type of widget is being rendered. For example for checkboxes I want the label before the input, so I did this:
{% block form_row %}
{% spaceless %}
<div class="row">
{% if form.vars.block_prefixes[1] == "checkbox" %}
{{ form_widget(form) }}
{{ form_label(form) }}
{{ form_errors(form) }}
{% else %}
<div class="small-12 medium-3 columns">
{{ form_label(form) }}
</div>
{{ form_widget(form) }}
{{ form_errors(form) }}
{% endif %}
</div>
{% endspaceless %}
{% endblock form_row %}
I used form.vars.block_prefixes[1] to determine the widget it's about to render. Is that right? Or is there a better method? I can't seem to find it in the docs.

Answer 1

If you see symfony cookbook, you can find:
the block name is a combination of the field type and which part of the field is being rendered (e.g. widget, label, errors, row)
So, to customize checkbox form type rendering, you can define checkbox_widget block and checkbox_row for widgets order:
{% block checkbox_widget %}
{% spaceless %}
<label {% for attrname, attrvalue in label_attr %} {{ attrname }}="{{ attrvalue }}"{% endfor %}>
{{ label }}
</label>
<input type="checkbox" {{ block('widget_attributes') }}{% if value is defined %} value="{{ value }}"{% endif %}{% if checked %} checked="checked"{% endif %} />
{% endspaceless %}
{% endblock checkbox_widget %}
{% block checkbox_row %}
{% spaceless %}
{{ form_widget(form) }}
{{ form_errors(form) }}
{% endspaceless %}
{% endblock checkbox_row %}

Answer 2

If there is any data you need in the templates and symfony doesn't provide it by default you can always create a form type extension
A form type extension is a mechanism that let's you extend many form types in a single place. You can extend all form types provided you define the right extended type (FormType::class if you want to extend all forms).
This extension provides both the block_type for the current instance and the class name for all form types. This let's you use these variables in any generic template (such as widget_attributes).
I only tested it on symfony 3.4
<?php
namespace YourBundle\Form\Extension;
use Symfony\Component\Form\AbstractTypeExtension;
use Symfony\Component\Form\FormInterface;
use Symfony\Component\Form\FormView;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\Form\Extension\Core\Type\FormType;
class FormTypeExtension extends AbstractTypeExtension
{
public function buildForm(FormBuilderInterface $builder, array $options)
{
}
public function buildView(FormView $view, FormInterface $form, array $options)
{
$type = $form->getConfig()->getType();
$inner_type = $type->getInnerType();
$view->vars = array_replace($view->vars, array(
'block_prefix' => $type->getBlockPrefix(),
'type_name' => get_class($inner_type)
));
}
public function getExtendedType()
{
return FormType::class;
}
}