class AjaxAddMore
Same name in other branches
- 8.x-1.x form_api_example/src/Form/AjaxAddMore.php \Drupal\form_api_example\Form\AjaxAddMore
- 4.0.x modules/form_api_example/src/Form/AjaxAddMore.php \Drupal\form_api_example\Form\AjaxAddMore
Implements the ajax demo form controller.
This example demonstrates using ajax callbacks to add people's names to a list of picnic attendees.
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
- class \Drupal\form_api_example\Form\DemoBase extends \Drupal\Core\Form\FormBase
- class \Drupal\form_api_example\Form\AjaxAddMore extends \Drupal\form_api_example\Form\DemoBase
- class \Drupal\form_api_example\Form\DemoBase extends \Drupal\Core\Form\FormBase
Expanded class hierarchy of AjaxAddMore
See also
\Drupal\Core\Form\ConfigFormBase
1 string reference to 'AjaxAddMore'
- 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/ AjaxAddMore.php, line 16
Namespace
Drupal\form_api_example\FormView source
class AjaxAddMore extends DemoBase {
/**
* Form with 'add more' and 'remove' buttons.
*
* This example shows a button to "add more" - add another textfield, and
* the corresponding "remove" button.
*/
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 $form;
}
/**
* {@inheritdoc}
*/
public function getFormId() {
return 'form_api_example_ajax_addmore';
}
/**
* Callback for both ajax-enabled buttons.
*
* Selects and returns the fieldset with the names in it.
*/
public function addmoreCallback(array &$form, FormStateInterface $form_state) {
return $form['names_fieldset'];
}
/**
* Submit handler for the "add-one-more" button.
*
* Increments the max counter and causes a rebuild.
*/
public function addOne(array &$form, FormStateInterface $form_state) {
$name_field = $form_state->get('num_names');
$add_button = $name_field + 1;
$form_state->set('num_names', $add_button);
// Since our buildForm() method relies on the value of 'num_names' to
// generate 'name' form elements, we have to tell the form to rebuild. If we
// don't do this, the form builder will not call buildForm().
$form_state->setRebuild();
}
/**
* Submit handler for the "remove one" button.
*
* Decrements the max counter and causes a form rebuild.
*/
public function removeCallback(array &$form, FormStateInterface $form_state) {
$name_field = $form_state->get('num_names');
if ($name_field > 1) {
$remove_button = $name_field - 1;
$form_state->set('num_names', $remove_button);
}
// Since our buildForm() method relies on the value of 'num_names' to
// generate 'name' form elements, we have to tell the form to rebuild. If we
// don't do this, the form builder will not call buildForm().
$form_state->setRebuild();
}
/**
* Final submit handler.
*
* Reports what values were finally set.
*/
public function submitForm(array &$form, FormStateInterface $form_state) {
$values = $form_state->getValue([
'names_fieldset',
'name',
]);
$output = $this->t('These people are coming to the picnic: @names', [
'@names' => implode(', ', $values),
]);
$this->messenger()
->addMessage($output);
}
}
Members
Title Sort descending | Modifiers | Object type | Summary | Overriden Title | Overrides |
---|---|---|---|---|---|
AjaxAddMore::addmoreCallback | public | function | Callback for both ajax-enabled buttons. | ||
AjaxAddMore::addOne | public | function | Submit handler for the "add-one-more" button. | ||
AjaxAddMore::buildForm | public | function | Form with 'add more' and 'remove' buttons. | Overrides FormInterface::buildForm | |
AjaxAddMore::getFormId | public | function | Returns a unique string identifying the form. | Overrides FormInterface::getFormId | |
AjaxAddMore::removeCallback | public | function | Submit handler for the "remove one" button. | ||
AjaxAddMore::submitForm | public | function | Final submit handler. | Overrides DemoBase::submitForm | |
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. | ||
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. |