Add custom form field that is not in entity - Sonata admin

Question

I'm using Sonata Admin in my project. I need to render a field that doesn't belong to entity.

Consider entity User with fields username & password . But I also need a extra field as hobby in form but it is not needed in User entity.

    $formMapper
       ->add('username')
       ->add('password')
       ->add('hobby');

But I'm getting the symfony error as,

Neither the property "hobby" nor one of the methods "getHobby()", "hobby()", "isHobby()", "hasHobby()", "__get()" exist and have public access in class "App\\Entity\\User".

How can I solve this? Thanks in advance!!

Answer 1

This answer for Symfony2 should still hold true if I am not mistaken: How to add additional non-entity fields to entity form in Symfony2

In symfony 2.1+, use mapped:

 $form = $this->createFormBuilder($promo) ->add('code', 'text') ->add('image', 'file', array( "mapped" => false, )) ->getForm(); 

https://symfony.com/doc/current/reference/forms/types/entity.html#mapped

type : boolean default : true

If you wish the field to be ignored when reading or writing to the object, you can set the mapped option to false .

So for your case it should be something like:

$formMapper
    ->add('username')
    ->add('password')
    ->add('hobby', null, [
        'mapped' => false
    ]);