Disable a field if another field is disabled

Question

I need to disable field A if field B is disabled too. Actually, my current field A has the following #states (altered using hook_alter_form) to disable it if field B or field C are empty:

/**
 * Implements hook_form_alter().
 */
function my_module_form_alter(&$form, $form_state, $form_id) {
 
  $form['field_a']['#states'] = [
    'disabled' => [
      [':input[name="field_b[0][value][date]"]' => ['empty' => TRUE]],
      'or',
      [':input[name="field_c[0][value][date]"]' => ['empty' => TRUE]],
    ],
  ];
}

And it works perfectly, but I need to add the condition mentioned before. I found this in the official documentation: https://www.drupal.org/docs/drupal-apis/form-api/conditional-form-fields and I tried to use some of them like 'readonly' or 'readwrite' but this didn't work. Can I evaluate properties like '#disabled' from here? something similar to this:

function my_module_form_alter(&$form, $form_state, $form_id) {

  $form['field_a']['#states'] = [
    'disabled' => [
      [':input[name="field_b[0][value][date]"]' => ['empty' => TRUE]],
      'or',
      [':input[name="field_c[0][value][date]"]' => ['empty' => TRUE]],
      'or',
      [':input[name="field_b"]' => ['#disabled' => TRUE]],
    ],
  ];
}

Answer 1

You can't do this with states here is what the docs says

The following states may be used when checking values of other fields:

empty
filled
checked
unchecked
expanded
collapsed
value

So, for this particular feature you will need to use some javascript or jquery.