I have an element `$form['elements']['manufacturer']`. On change, I want to change `$form['elements']['form_factor']` and `$form['elements']['model']`.

Currently I have:

```
$form['elements']['manufacturer']['#ajax'] = [
    'callback' => 'formChanged',
    'wrapper' => 'form-factor',
    'event' => 'change',
];

```

which works and changes the form-factor. But, **I want to change the model** as well.

Iniside `formChanged` return form-factor in the callback function, so I can't return model element.

```
function formChanged(array &$form, FormStateInterface $formState){
  $form["elements"]["form_factor"]["#value"] = 0;
  return $form["elements"]["form_factor"];
}

```

[Reading from past posts](https://drupal.stackexchange.com/questions/7243/can-i-use-ajax-to-target-multiple-form-elements-from-one-input#answer-84593), one option was to return the whole form inside `formChanged` (`return $form`), but this doesn't seem like a good approach.

I can't do something like, having 2 callbacks:

```
$form['elements']['manufacturer']['#ajax'] = [
   [
    'callback' => 'formChanged',
    'wrapper' => 'form-factor',
    'event' => 'change',
   ],
   [
    'callback' => 'anothercallback',
    'wrapper' => 'another-one',
    'event' => 'change',
   ]
];

```