class Dropdown in Open Social 8.9

Provides an dropdown element.

Plugin annotation

@RenderElement("dropdown");

Hierarchy

• class \Drupal\Component\Plugin\PluginBase implements DerivativeInspectionInterface, PluginInspectionInterface
  • class \Drupal\Core\Plugin\PluginBase uses DependencySerializationTrait, MessengerTrait, StringTranslationTrait
    • class \Drupal\Core\Render\Element\RenderElement implements ElementInterface
      • class \Drupal\Core\Render\Element\FormElement implements FormElementInterface
        • class \Drupal\dropdown\Element\Dropdown uses CompositeFormElementTrait

1 string reference to 'Dropdown'

dropdown.info.yml in modules/custom/dropdown/dropdown.info.yml

modules/custom/dropdown/dropdown.info.yml

1 #type use of Dropdown

DropdownWidgetType::formElement in modules/custom/dropdown/src/Plugin/Field/FieldWidget/DropdownWidgetType.php

Returns the form for a single field widget.

File

modules/custom/dropdown/src/Element/Dropdown.php, line 15

Namespace

Drupal\dropdown\Element

class Dropdown extends FormElement {
  use CompositeFormElementTrait;

  /**
   * {@inheritdoc}
   */
  public function getInfo() {
    $class = get_class($this);
    return [
      '#label' => 'Default Label',
      '#process' => [
        [
          $class,
          'processDropdown',
        ],
      ],
      '#description' => t('Dropdown element.'),
      '#theme_wrappers' => [
        'dropdown',
      ],
      '#pre_render' => [
        [
          $class,
          'preRenderDropdown',
        ],
      ],
    ];
  }

  /**
   * Prepare the render array for the template.
   */
  public static function preRenderDropdown($element) {

    // @TODO Attach $element['#attached']['library'][] = 'dropdown';
    return $element;
  }

  /**
   * Expands a radios element into individual radio elements.
   */
  public static function processDropdown(&$element, FormStateInterface $form_state, &$complete_form) {
    if (count($element['#options']) > 0) {
      $weight = 0;
      foreach ($element['#options'] as $key => $option) {
        $value = HtmlUtility::escape($option['value']);
        $label = HtmlUtility::escape($option['label']);
        $description = isset($option['description']) ? HtmlUtility::escape($option['description']) : NULL;

        // Maintain order of options as defined in #options, in case the element
        // defines custom option sub-elements, but does not define all option
        // sub-elements.
        $weight += 0.001;
        $element += [
          $key => [],
        ];

        // Generate the parents as the autogenerator does, so we will have a
        // unique id for each radio button.
        $parents_for_id = array_merge($element['#parents'], [
          $key,
        ]);
        $element[$key] += [
          '#type' => 'radio',
          '#title' => $label,
          '#description' => $description,
          // The key is sanitized in Drupal\Core\Template\Attribute during
          // output from the theme function.
          '#return_value' => $value,
          // Use default or FALSE. A value of FALSE means that the radio button
          // is not 'checked'.
          '#default_value' => isset($element['#default_value']) ? $element['#default_value'] : FALSE,
          '#attributes' => $element['#attributes'],
          '#parents' => $element['#parents'],
          '#id' => HtmlUtility::getUniqueId('edit-' . implode('-', $parents_for_id)),
          '#ajax' => isset($element['#ajax']) ? $element['#ajax'] : NULL,
          // Errors should only be shown on the parent radios element.
          '#error_no_message' => TRUE,
          '#weight' => $weight,
        ];
      }
    }
    return $element;
  }

  /**
   * {@inheritdoc}
   */
  public static function valueCallback(&$element, $input, FormStateInterface $form_state) {
    if ($input !== FALSE) {

      // When there's user input (including NULL), return it as the value.
      // However, if NULL is submitted, FormBuilder::handleInputElement() will
      // apply the default value, and we want that validated against #options
      // unless it's empty. (An empty #default_value, such as NULL or FALSE, can
      // be used to indicate that no radio button is selected by default.)
      if (!isset($input) && !empty($element['#default_value'])) {
        $element['#needs_validation'] = TRUE;
      }
      return $input;
    }
    else {

      // For default value handling, simply return #default_value. Additionally,
      // for a NULL default value, set #has_garbage_value to prevent
      // FormBuilder::handleInputElement() converting the NULL to an empty
      // string, so that code can distinguish between nothing selected and the
      // selection of a radio button whose value is an empty string.
      $value = isset($element['#default_value']) ? $element['#default_value'] : NULL;
      if (!isset($value)) {
        $element['#has_garbage_value'] = TRUE;
      }
      return $value;
    }
  }

}

Members

Name	Modifiers	Type	Description	Overrides
CompositeFormElementTrait::preRenderCompositeFormElement	public static	function	Adds form element theming to an element if its title or description is set.
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
Dropdown::getInfo	public	function	Returns the element properties for this element. Overrides ElementInterface::getInfo
Dropdown::preRenderDropdown	public static	function	Prepare the render array for the template.
Dropdown::processDropdown	public static	function	Expands a radios element into individual radio elements.
Dropdown::valueCallback	public static	function	Determines how user input is mapped to an element's #value property. Overrides FormElement::valueCallback
FormElement::processAutocomplete	public static	function	Adds autocomplete functionality to elements.
FormElement::processPattern	public static	function	#process callback for #pattern form element property.
FormElement::validatePattern	public static	function	#element_validate callback for #pattern form element property.
MessengerTrait::$messenger	protected	property	The messenger.	29
MessengerTrait::messenger	public	function	Gets the messenger.	29
MessengerTrait::setMessenger	public	function	Sets the messenger.
PluginBase::$configuration	protected	property	Configuration information passed into the plugin.	1
PluginBase::$pluginDefinition	protected	property	The plugin implementation definition.	1
PluginBase::$pluginId	protected	property	The plugin_id.
PluginBase::DERIVATIVE_SEPARATOR		constant	A string which is used to separate base plugin IDs from the derivative ID.
PluginBase::getBaseId	public	function	Gets the base_plugin_id of the plugin instance. Overrides DerivativeInspectionInterface::getBaseId
PluginBase::getDerivativeId	public	function	Gets the derivative_id of the plugin instance. Overrides DerivativeInspectionInterface::getDerivativeId
PluginBase::getPluginDefinition	public	function	Gets the definition of the plugin implementation. Overrides PluginInspectionInterface::getPluginDefinition	3
PluginBase::getPluginId	public	function	Gets the plugin_id of the plugin instance. Overrides PluginInspectionInterface::getPluginId
PluginBase::isConfigurable	public	function	Determines if the plugin is configurable.
PluginBase::__construct	public	function	Constructs a \Drupal\Component\Plugin\PluginBase object.	92
RenderElement::preRenderAjaxForm	public static	function	Adds Ajax information about an element to communicate with JavaScript.
RenderElement::preRenderGroup	public static	function	Adds members of this group as actual elements for rendering.
RenderElement::processAjaxForm	public static	function	Form element processing handler for the #ajax form property.	1
RenderElement::processGroup	public static	function	Arranges elements into groups.
RenderElement::setAttributes	public static	function	Sets a form element's class attribute. Overrides ElementInterface::setAttributes
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.