Avoid Symfony forcing form fields display

I guess you have a form_end or form_rest somewhere after your presented code.

You can tell to not render remaining fields in the form_end helper :

{# don't render unrendered fields #}
{{ form_end(form, {'render_rest': false}) }}

http://symfony.com/doc/current/reference/forms/twig_reference.html

BTW, I would suggest to add your logic in your FormType.

You can force the items to having been rendered like..

{% do form.filterStart.setRendered %}
{% do form.filterEnd.setRendered %}

If you are using {{ form_end(form, {'render_rest': false}) }} then you should be aware that you would need to render your CSRF token, unless you have specifically turned it off.

Both of these approaches may clear the values on your model due to them not being in the posted data.

Alternatively you can just place the fields in a hidden div, but this is a little hacky (then again the other ways are too).

The best way, as mentioned by Christophe, would be to add this into your form logic. The way you choose to do this would depend on whether the availability of these fields depends on a predetermined factor or on data coming from the actual model.

Predetermined

Your Form Type

class YourFormType extends AbstractType
{
    //...

    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        //...

        if ($options['your_condition']) {
            $builder
                ->add('filterStart', 'date')
                ->add('filterEnd', 'date')
            ;
        }
    }

    public function setDefaultOptions(OptionsResolverInterface $resolver)
    {
        $resolver->setDefaults(array(
            //...
            'your_condition' => false,
        ));
    }

    //...
}

Creating Your Form

$form = $formFactory->create(
        // Or $this->createForm if you are using the controller
    'your_form_name', 
    $model, 
    array('your_condition' => true/false)
);

From The Model

Form Type

class YourFormType extends AbstractType
{
    //...

    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        //...

        $builder
            ->addEventListener(FormEvents::PRE_SET_DATA, function(FormEvent $event) {
                $form = $event->getForm();
                $model = $event->getData();

                if (!$model || 'something' !== $model->getSomething()) {
                    return;
                }

                $form
                    ->add('filterStart', 'date')
                    ->add('filterEnd', 'date')
                ;
            })
        ;
    }

    //...
}

Bother of these would then require you to check that the fields had been created when rendering them in your template like..

{% if form.filterStart is defined and form.filterEnd is defiend %}
    <div class="container-filters">
        <div class="form-group">
            {{ form_row(form.filterStart) }}
        </div>
        <div class="form-group">
            {{ form_row(form.filterEnd) }}
        </div>
        <input type="submit" name="submit" class="btn btn-evo" value="OK" />
    </div>
{% endif %}

Since FormView->children has public access you can handle the logic into your controller:

if(<condition>) {
    $formView->children['filterStart']->setRendered();
    $formView->children['filterEnd']->setRendered();
}

If you have 1 form that you want to display differently on two template you can remove a specific field directly in your Controller:

public function firstWayAction()
{
    $form = $this->createForm(new RemoveFormFieldType());

    $form->remove('second');

    // form processing...   
    return $this->render('QADayBundle:RemoveFormField:form.html.twig', array(
        'form' => $form->createView()
    ));
}

See this article for more details: https://symfonycasts.com/screencast/question-answer-day/remove-form-field

you can set "style=display:none" in your twig.

<div style= "display:none">
    {{ form_row(form.filterStart) }}
</div>