How to pass a simple variable into form for twig? Not a form element

Oleh Bardiuk

1/16/24, 2:44 PM

I have a form that is working just fine. Now I need to make some logic in its twig file based on some field value. How do I pass that variable into twig? I tried a simple solution and it works, but I get errors.

$form['dates']['arrival'] = [
  '#type' => 'date',
  '#title' => $this->t('Arrival'),
  '#required' => TRUE,
  '#default_value' => $form_state->getValue(
    ['dates', 'arrival'],
  ),
];

$form['some_value'] = $form_state->get('max_guests');

Whatever I do I get:

User error: "some_value" is an invalid render array key in Drupal\Core\Render\Element::children()....

I have seen the other answer, I defined

$form['#max_guests'] = $form_state->get('max_guests') ?? 0;

Now I can not output it in twig.

I tried

{{ element.max_guests }}

{{ max_guests }}

Nothing works, please help

0 + 3

4uk4

1/16/24, 4:37 PM

@Jaypan, that would be two solutions at once. You only need one, either put a hash tag in front of the form key or, if you want to render the form key together with the other form elements, build a render array, for example with `#markup`. Oleh Bardiuk, the answer to the last part of your question is: `{{ element['#max_guests'] }}` or `{{ form['#max_guests'] }}`.

Jaypan

1/16/24, 5:27 PM

Oh yes, I didn't notice the hashtag on the code I copied. Deleted my comment.

Oleh Bardiuk

1/17/24, 2:23 PM

Yeah, the old good PHP's `element['#max_guests']` helped, thanks. <irony>Things are very intuitive and consistent in twig</irony>

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