public function AjaxAddMore::buildForm in Examples for Developers 8

Same name and namespace in other branches

1. 3.x modules/form_api_example/src/Form/AjaxAddMore.php \Drupal\form_api_example\Form\AjaxAddMore::buildForm()

Form with 'add more' and 'remove' buttons.

This example shows a button to "add more" - add another textfield, and the corresponding "remove" button.

Overrides FormInterface::buildForm

File

form_api_example/src/Form/AjaxAddMore.php, line 24

Class

AjaxAddMore

Implements the ajax demo form controller.

Namespace

Drupal\form_api_example\Form

Code

public function buildForm(array $form, FormStateInterface $form_state) {
  $form['description'] = [
    '#type' => 'item',
    '#markup' => $this
      ->t('This example shows an add-more and a remove-last button.'),
  ];

  // Gather the number of names in the form already.
  $num_names = $form_state
    ->get('num_names');

  // We have to ensure that there is at least one name field.
  if ($num_names === NULL) {
    $name_field = $form_state
      ->set('num_names', 1);
    $num_names = 1;
  }
  $form['#tree'] = TRUE;
  $form['names_fieldset'] = [
    '#type' => 'fieldset',
    '#title' => $this
      ->t('People coming to picnic'),
    '#prefix' => '<div id="names-fieldset-wrapper">',
    '#suffix' => '</div>',
  ];
  for ($i = 0; $i < $num_names; $i++) {
    $form['names_fieldset']['name'][$i] = [
      '#type' => 'textfield',
      '#title' => $this
        ->t('Name'),
    ];
  }
  $form['names_fieldset']['actions'] = [
    '#type' => 'actions',
  ];
  $form['names_fieldset']['actions']['add_name'] = [
    '#type' => 'submit',
    '#value' => $this
      ->t('Add one more'),
    '#submit' => [
      '::addOne',
    ],
    '#ajax' => [
      'callback' => '::addmoreCallback',
      'wrapper' => 'names-fieldset-wrapper',
    ],
  ];

  // If there is more than one name, add the remove button.
  if ($num_names > 1) {
    $form['names_fieldset']['actions']['remove_name'] = [
      '#type' => 'submit',
      '#value' => $this
        ->t('Remove one'),
      '#submit' => [
        '::removeCallback',
      ],
      '#ajax' => [
        'callback' => '::addmoreCallback',
        'wrapper' => 'names-fieldset-wrapper',
      ],
    ];
  }
  $form['actions']['submit'] = [
    '#type' => 'submit',
    '#value' => $this
      ->t('Submit'),
  ];
  return $form;
}