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class Autotextfields in Examples for Developers 8

Same name and namespace in other branches
  1. 3.x modules/ajax_example/src/Form/Autotextfields.php \Drupal\ajax_example\Form\Autotextfields

Show textfields based on AJAX-enabled checkbox clicks.

Hierarchy

Expanded class hierarchy of Autotextfields

Related topics

Example: AJAX
These examples show basic AJAX concepts.
1 string reference to 'Autotextfields'
ajax_example.routing.yml in ajax_example/ajax_example.routing.yml
ajax_example/ajax_example.routing.yml

File

ajax_example/src/Form/Autotextfields.php, line 13

Namespace

Drupal\ajax_example\Form
View source 
class Autotextfields extends FormBase {

  /**
   * {@inheritdoc}
   */
  public function getFormId() {
    return 'ajax_example_autotextfields';
  }

  /**
   * {@inheritdoc}
   *
   * This form has two checkboxes which the user can check in order to then
   * reveal the first and/or last name text fields.
   *
   * We could perform this behavior with #states. We might not want to if, for
   * instance, we wanted to require a name, but let the user choose whether
   * to enter first or last or both.
   *
   * For all the requests this class gets, the buildForm() method will always be
   * called. If an AJAX request comes in, the form state will be set to the
   * state the user changed that caused the AJAX request. So if the user enabled
   * one of our checkboxes, it will be checked in $form_state.
   */
  public function buildForm(array $form, FormStateInterface $form_state) {
    $form['description'] = [
      '#type' => 'item',
      '#markup' => $this
        ->t('This form demonstrates changing the status of form elements through AJAX requests.'),
    ];
    $form['ask_first_name'] = [
      '#type' => 'checkbox',
      '#title' => $this
        ->t('Ask me my first name'),
      '#ajax' => [
        'callback' => '::textfieldsCallback',
        'wrapper' => 'textfields-container',
        'effect' => 'fade',
      ],
    ];
    $form['ask_last_name'] = [
      '#type' => 'checkbox',
      '#title' => $this
        ->t('Ask me my last name'),
      '#ajax' => [
        'callback' => '::textfieldsCallback',
        'wrapper' => 'textfields-container',
        'effect' => 'fade',
      ],
    ];

    // Wrap textfields in a container. This container will be replaced through
    // AJAX.
    $form['textfields_container'] = [
      '#type' => 'container',
      '#attributes' => [
        'id' => 'textfields-container',
      ],
    ];
    $form['textfields_container']['textfields'] = [
      '#type' => 'fieldset',
      '#title' => $this
        ->t("Generated text fields for first and last name"),
      '#description' => $this
        ->t('This is where we put automatically generated textfields'),
    ];

    // This form is rebuilt on all requests, so whether or not the request comes
    // from AJAX, we should rebuild everything based on the form state.
    // Checkbox values are expressed as 1 or 0, so we have to be sure to compare
    // type as well as value.
    if ($form_state
      ->getValue('ask_first_name', NULL) === 1) {
      $form['textfields_container']['textfields']['first_name'] = [
        '#type' => 'textfield',
        '#title' => $this
          ->t('First Name'),
        '#required' => TRUE,
      ];
    }
    if ($form_state
      ->getValue('ask_last_name', NULL) === 1) {
      $form['textfields_container']['textfields']['last_name'] = [
        '#type' => 'textfield',
        '#title' => $this
          ->t('Last Name'),
        '#required' => TRUE,
      ];
    }
    $form['textfields_container']['submit'] = [
      '#type' => 'submit',
      '#value' => $this
        ->t('Click Me'),
    ];
    return $form;
  }

  /**
   * {@inheritdoc}
   */
  public function submitForm(array &$form, FormStateInterface $form_state) {
    $this
      ->messenger()
      ->addMessage($this
      ->t('Submit handler: First name: @first_name Last name: @last_name', [
      '@first_name' => $form_state
        ->getValue('first_name', 'n/a'),
      '@last_name' => $form_state
        ->getValue('last_name', 'n/a'),
    ]));
  }

  /**
   * Callback for ajax_example_autotextfields.
   *
   * Selects the piece of the form we want to use as replacement markup and
   * returns it as a form (renderable array).
   */
  public function textfieldsCallback($form, FormStateInterface $form_state) {
    return $form['textfields_container'];
  }

}

Members

Namesort descending Modifiers Type Description Overrides
Autotextfields::buildForm public function This form has two checkboxes which the user can check in order to then reveal the first and/or last name text fields. Overrides FormInterface::buildForm
Autotextfields::getFormId public function Returns a unique string identifying the form. Overrides FormInterface::getFormId
Autotextfields::submitForm public function Form submission handler. Overrides FormInterface::submitForm
Autotextfields::textfieldsCallback public function Callback for ajax_example_autotextfields.
DependencySerializationTrait::$_entityStorages protected property An array of entity type IDs keyed by the property name of their storages.
DependencySerializationTrait::$_serviceIds protected property An array of service IDs keyed by property name used for serialization.
DependencySerializationTrait::__sleep public function 1
DependencySerializationTrait::__wakeup public function 2
FormBase::$configFactory protected property The config factory. 1
FormBase::$requestStack protected property The request stack. 1
FormBase::$routeMatch protected property The route match.
FormBase::config protected function Retrieves a configuration object.
FormBase::configFactory protected function Gets the config factory for this form. 1
FormBase::container private function Returns the service container.
FormBase::create public static function Instantiates a new instance of this class. Overrides ContainerInjectionInterface::create 87
FormBase::currentUser protected function Gets the current user.
FormBase::getRequest protected function Gets the request object.
FormBase::getRouteMatch protected function Gets the route match.
FormBase::logger protected function Gets the logger for a specific channel.
FormBase::redirect protected function Returns a redirect response object for the specified route. Overrides UrlGeneratorTrait::redirect
FormBase::resetConfigFactory public function Resets the configuration factory.
FormBase::setConfigFactory public function Sets the config factory for this form.
FormBase::setRequestStack public function Sets the request stack object to use.
FormBase::validateForm public function Form validation handler. Overrides FormInterface::validateForm 62
LinkGeneratorTrait::$linkGenerator protected property The link generator. 1
LinkGeneratorTrait::getLinkGenerator Deprecated protected function Returns the link generator.
LinkGeneratorTrait::l Deprecated protected function Renders a link to a route given a route name and its parameters.
LinkGeneratorTrait::setLinkGenerator Deprecated public function Sets the link generator service.
LoggerChannelTrait::$loggerFactory protected property The logger channel factory service.
LoggerChannelTrait::getLogger protected function Gets the logger for a specific channel.
LoggerChannelTrait::setLoggerFactory public function Injects the logger channel factory.
MessengerTrait::$messenger protected property The messenger. 29
MessengerTrait::messenger public function Gets the messenger. 29
MessengerTrait::setMessenger public function Sets the messenger.
RedirectDestinationTrait::$redirectDestination protected property The redirect destination service. 1
RedirectDestinationTrait::getDestinationArray protected function Prepares a 'destination' URL query parameter for use with \Drupal\Core\Url.
RedirectDestinationTrait::getRedirectDestination protected function Returns the redirect destination service.
RedirectDestinationTrait::setRedirectDestination public function Sets the redirect destination service.
StringTranslationTrait::$stringTranslation protected property The string translation service. 1
StringTranslationTrait::formatPlural protected function Formats a string containing a count of items.
StringTranslationTrait::getNumberOfPlurals protected function Returns the number of plurals supported by a given language.
StringTranslationTrait::getStringTranslation protected function Gets the string translation service.
StringTranslationTrait::setStringTranslation public function Sets the string translation service to use. 2
StringTranslationTrait::t protected function Translates a string to the current language or to a given language.
UrlGeneratorTrait::$urlGenerator protected property The url generator.
UrlGeneratorTrait::getUrlGenerator Deprecated protected function Returns the URL generator service.
UrlGeneratorTrait::setUrlGenerator Deprecated public function Sets the URL generator service.
UrlGeneratorTrait::url Deprecated protected function Generates a URL or path for a specific route based on the given parameters.