How to allow a checkbox to be empty in symfony?

This error is because the input is marked with the HTML5 attribute required="required". In your form type you can disable this by setting the required option to false on this checkbox.

$builder->add('updatesNeeded', 'choice', array('required' => false));

http://symfony.com/doc/current/book/forms.html#book-forms-html5-validation-disable

What about just using nullable=""

Okay it seems that I was using the wrong version of my site. All of the methods mentioned work, and I just want to summarize them below for anyone who runs into such a problem in the future.

The issue here is that HTML5 likes to validate forms by itself and adds a required="required" to any form input. Usually, this is probably a useful thing, but for some things like checkboxes, you want the option of leaving them unchecked and submitting the form without the browser complaining on the client side.

There are several ways to solve this problem, some better than others.

The first is to simply disable all validation for the form using HTML5, as mentioned by the official symfony docs.

Another is to add information to the entity variable in the comments, making nullable=true. This allows the corresponding column in your database to have null values, which may or may not be desirable for your situation. This is shown below.

/** * @var boolean $varName * * @ORM\Column(name="var_name", type="boolean", nullable=true) */private $varName;

Finally, when building the form, there are certain options that you can use for validation in the forms. The docs detail and give more examples, but for our purposes here, the important part is that you can set 'required' => false, as I've shown below.

use Symfony\Component\Form\AbstractType;use Symfony\Component\Form\FormBuilder;class BlahType extends AbstractType{    /**     * @param \Symfony\Component\Form\FormBuilder $builder     * @param array                               $options     */    public function buildForm(FormBuilder $builder, array $options)    {        $builder            ->add('stuff')            ->add('checkbox_var', 'checkbox', array('required' => false))            ->add('anothervar');    }}

Thank you to all the people who helped me with this issue. I hope this helps someone who has to deal with these sorts of issues in the future.