Form constructor.

Parameters

array $form: An associative array containing the structure of the form.

\Drupal\Core\Form\FormStateInterface $form_state: The current state of the form.

Return value

array The form structure.

Overrides FormInterface::buildForm

File

core/modules/system/tests/modules/test_htmx/src/Form/HtmxTestForm.php, line 27

Class

HtmxTestForm

A small form used to test HTMX dynamic forms.

Namespace

Drupal\test_htmx\Form

Code

public function buildForm(array $form, FormStateInterface $form_state, ?string $type = NULL, ?string $selected = NULL) {
  $type = $type ?? '';
  $selected = $selected ?? '';
  $formUrl = Url::fromRoute('<current>');
  $form['type'] = [
    '#type' => 'select',
    '#title' => 'Type',
    '#empty_value' => '',
    '#options' => [
      'a' => 'A',
      'b' => 'B',
    ],
    '#default_value' => $type,
  ];
  (new Htmx())->post($formUrl)
    ->swap('none')
    ->swapOob('true')
    ->applyTo($form['type']);
  $defaultType = $form_state->getValue('type', $type);
  $form['selected'] = [
    '#type' => 'select',
    '#title' => 'Selected',
    '#options' => $this->buildDependentOptions($defaultType),
    '#empty_value' => '',
    '#default_value' => $selected,
  ];
  (new Htmx())->post($formUrl)
    ->swap('none')
    ->swapOob('true')
    ->applyTo($form['selected']);
  $form['data'] = [
    '#title' => 'Values',
    '#type' => 'item',
    '#markup' => '',
  ];
  (new Htmx())->swapOob(TRUE)
    ->applyTo($form['data'], '#wrapper_attributes');
  $push = FALSE;
  if ($this->getTriggerElement($form_state) === 'type') {
    $form['data']['#markup'] = '';
    $push = Url::fromRoute('test_htmx.form_builder_test');
  }
  elseif ($this->getTriggerElement($form_state) === 'selected') {
    // A value is selected.
    $defaultSelection = $form_state->getValue('selected', $selected);
    // Also update the browser URL.
    $push = Url::fromRoute('test_htmx.form_builder_test', [
      'type' => $defaultType,
      'selected' => $defaultSelection,
    ]);
    if ($defaultType && $defaultSelection) {
      $form['data']['#markup'] = "Data is {$defaultType}:{$defaultSelection}";
    }
  }
  elseif ($type && $selected) {
    $form['data']['#markup'] = "Data is {$type}:{$selected}";
  }
  if ($push) {
    $htmxPost = (new Htmx())->post($push)
      ->pushUrlHeader($push);
    $htmxPost->applyTo($form['type']);
    $htmxPost->applyTo($form['selected']);
  }
  return $form;
}

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