class Simplest

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

A relatively simple AJAX demonstration form.

Hierarchy

Expanded class hierarchy of Simplest

1 string reference to 'Simplest'
ajax_example.routing.yml in modules/ajax_example/ajax_example.routing.yml
modules/ajax_example/ajax_example.routing.yml

File

modules/ajax_example/src/Form/Simplest.php, line 11

Namespace

Drupal\ajax_example\Form
View source
class Simplest extends FormBase {
    
    /**
     * {@inheritdoc}
     */
    public function getFormId() {
        return 'ajax_example_simplest';
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildForm(array $form, FormStateInterface $form_state) {
        $form['changethis'] = [
            '#title' => $this->t("Choose something and explain why"),
            '#type' => 'select',
            '#options' => [
                'one' => 'one',
                'two' => 'two',
                'three' => 'three',
            ],
            '#ajax' => [
                // #ajax has two required keys: callback and wrapper.
                // 'callback' is a function that will be called when this element
                // changes.
'callback' => '::promptCallback',
                // 'wrapper' is the HTML id of the page element that will be replaced.
'wrapper' => 'replace-textfield-container',
            ],
        ];
        // The 'replace-textfield-container' container will be replaced whenever
        // 'changethis' is updated.
        $form['replace_textfield_container'] = [
            '#type' => 'container',
            '#attributes' => [
                'id' => 'replace-textfield-container',
            ],
        ];
        $form['replace_textfield_container']['replace_textfield'] = [
            '#type' => 'textfield',
            '#title' => $this->t("Why"),
        ];
        // An AJAX request calls the form builder function for every change.
        // We can change how we build the form based on $form_state.
        $value = $form_state->getValue('changethis');
        // The getValue() method returns NULL by default if the form element does
        // not exist. It won't exist yet if we're building it for the first time.
        if ($value !== NULL) {
            $form['replace_textfield_container']['replace_textfield']['#description'] = $this->t("Say why you chose '@value'", [
                '@value' => $value,
            ]);
        }
        return $form;
    }
    
    /**
     * {@inheritdoc}
     */
    public function submitForm(array &$form, FormStateInterface $form_state) {
        // No-op. Our form doesn't need a submit handler, because the form is never
        // submitted. We add the method here so we fulfill FormInterface.
    }
    
    /**
     * Handles switching the available regions based on the selected theme.
     */
    public function promptCallback($form, FormStateInterface $form_state) {
        return $form['replace_textfield_container'];
    }

}

Members

Title Sort descending Modifiers Object type Summary Overriden Title Overrides
DependencySerializationTrait::$_entityStorages protected property
DependencySerializationTrait::$_serviceIds protected property
DependencySerializationTrait::__sleep public function 1
DependencySerializationTrait::__wakeup public function 2
FormBase::$configFactory protected property The config factory. 3
FormBase::$requestStack protected property The request stack. 1
FormBase::$routeMatch protected property The route match.
FormBase::config protected function Retrieves a configuration object.
FormBase::configFactory protected function Gets the config factory for this form. 3
FormBase::container private function Returns the service container.
FormBase::create public static function Instantiates a new instance of this class. Overrides ContainerInjectionInterface::create 111
FormBase::currentUser protected function Gets the current user. 2
FormBase::getRequest protected function Gets the request object.
FormBase::getRouteMatch protected function Gets the route match.
FormBase::logger protected function Gets the logger for a specific channel.
FormBase::redirect protected function Returns a redirect response object for the specified route.
FormBase::resetConfigFactory public function Resets the configuration factory.
FormBase::setConfigFactory public function Sets the config factory for this form.
FormBase::setRequestStack public function Sets the request stack object to use.
FormBase::validateForm public function Form validation handler. Overrides FormInterface::validateForm 57
LoggerChannelTrait::$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::$messenger protected property The messenger. 16
MessengerTrait::messenger public function Gets the messenger. 16
MessengerTrait::setMessenger public function Sets the messenger.
RedirectDestinationTrait::$redirectDestination protected property The redirect destination service. 2
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.
Simplest::buildForm public function Form constructor. Overrides FormInterface::buildForm
Simplest::getFormId public function Returns a unique string identifying the form. Overrides FormInterface::getFormId
Simplest::promptCallback public function Handles switching the available regions based on the selected theme.
Simplest::submitForm public function Form submission handler. Overrides FormInterface::submitForm
StringTranslationTrait::$stringTranslation protected property The string translation service. 3
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.