EntityType Symfony set default as null

Question

I would like how could a make that my first option of an EntityType is NULL.

I've tried with a placeholder, but is not possible because when I try to register the form it obligate to select a different option which is not the place holder.

I'm trying something like this:

->add('idacademicprogram', EntityType::class, array(
            "class" => 'AppBundle:Academicprogram',
            'placeholder' => 'Choose an option',
            "attr"=>array(
                "class" => "form-iduser form-control",
                "required" => false
            )))

Answer 1

Ok i fixed changing required on global array, not on attr.

Would be something like this:

->add('idacademicprogram', EntityType::class, array(
            "class" => 'AppBundle:Academicprogram',
            'placeholder' => 'Choose an option',
            'required' => false,
            "attr"=>array(
                "class" => "form-iduser form-control"
            )))