class StateDemo
Same name in other branches
- 8.x-1.x form_api_example/src/Form/StateDemo.php \Drupal\form_api_example\Form\StateDemo
- 4.0.x modules/form_api_example/src/Form/StateDemo.php \Drupal\form_api_example\Form\StateDemo
Implements the state demo form controller.
This example demonstrates using the #states property to bind the visibility of a form element to the value of another element in the form. In the example, when the user checks the "Need Special Accommodation" checkbox, additional form elements are made visible.
The submit handler for this form is implemented by the \Drupal\form_api_example\Form\DemoBase class.
Hierarchy
- class \Drupal\Core\Form\FormBase implements \Drupal\Core\Form\FormInterface, \Drupal\Core\DependencyInjection\ContainerInjectionInterface uses \Drupal\Core\DependencyInjection\DependencySerializationTrait, \Drupal\Core\Logger\LoggerChannelTrait, \Drupal\Core\Messenger\MessengerTrait, \Drupal\Core\Routing\RedirectDestinationTrait, \Drupal\Core\StringTranslation\StringTranslationTrait
Expanded class hierarchy of StateDemo
See also
\Drupal\form_api_example\Form\DemoBase
drupal_process_states()
1 string reference to 'StateDemo'
- form_api_example.routing.yml in modules/
form_api_example/ form_api_example.routing.yml - modules/form_api_example/form_api_example.routing.yml
File
-
modules/
form_api_example/ src/ Form/ StateDemo.php, line 22
Namespace
Drupal\form_api_example\FormView source
class StateDemo extends DemoBase {
/**
* Build the simple form.
*
* @inheritdoc
*/
public function buildForm(array $form, FormStateInterface $form_state) {
$form['description'] = [
'#type' => 'item',
'#markup' => $this->t('This example demonstrates the #states property. #states makes an element visibility dependent on another.'),
];
$form['needs_accommodation'] = [
'#type' => 'checkbox',
'#title' => 'Need Special Accommodations?',
];
// The #states property used here binds the visibility of the
// container element to the value of the needs_accommodation checkbox above.
$form['accommodation'] = [
'#type' => 'container',
'#attributes' => [
'class' => 'accommodation',
],
// #states is an associative array. Each key is the name of a state to
// apply to the element, such as 'visible'. Each value is another array,
// making a list of conditions that denote when the state should be
// applied. Every condition is a key/value pair, whose key is a jQuery
// selector that denotes another element on the page, and whose value is
// an array of conditions, which must be met on in order for the state to
// be applied.
//
// For additional documentation on the #states property including a list
// of valid states and conditions see drupal_process_states().
'#states' => [
// The state being affected is "invisible".
'invisible' => [
// Drupal will only apply this state when the element that satisfies
// the selector input[name="needs_accommodation"] is un-checked.
':input[name="needs_accommodation"]' => [
'checked' => FALSE,
],
],
],
];
$form['accommodation']['diet'] = [
'#type' => 'textfield',
'#title' => $this->t('Dietary Restrictions'),
];
// Add a submit button that handles the submission of the form.
$form['actions']['submit'] = [
'#type' => 'submit',
'#value' => $this->t('Submit'),
];
return $form;
}
/**
* Getter method for Form ID.
*
* @inheritdoc
*/
public function getFormId() {
return 'form_api_example_state_demo';
}
/**
* Implements submitForm callback.
*
* @inheritdoc
*/
public function submitForm(array &$form, FormStateInterface $form_state) {
// Find out what was submitted.
$values = $form_state->getValues();
if ($values['needs_accommodation']) {
$this->messenger()
->addMessage($this->t('Dietary Restriction Requested: %diet', [
'%diet' => $values['diet'],
]));
}
}
}
Members
Title Sort descending | Modifiers | Object type | Summary | Overriden Title | Overrides |
---|---|---|---|---|---|
DependencySerializationTrait::$_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 | 105 |
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. | ||
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 | 73 |
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. | 17 | |
MessengerTrait::messenger | public | function | Gets the messenger. | 17 | |
MessengerTrait::setMessenger | public | function | Sets the messenger. | ||
RedirectDestinationTrait::$redirectDestination | protected | property | The redirect destination service. | 1 | |
RedirectDestinationTrait::getDestinationArray | protected | function | Prepares a 'destination' URL query parameter for use with \Drupal\Core\Url. | ||
RedirectDestinationTrait::getRedirectDestination | protected | function | Returns the redirect destination service. | ||
RedirectDestinationTrait::setRedirectDestination | public | function | Sets the redirect destination service. | ||
StateDemo::buildForm | public | function | Build the simple form. | Overrides FormInterface::buildForm | |
StateDemo::getFormId | public | function | Getter method for Form ID. | Overrides FormInterface::getFormId | |
StateDemo::submitForm | public | function | Implements submitForm callback. | Overrides DemoBase::submitForm | |
StringTranslationTrait::$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. |