trait RecipeInputFormTrait

trait RecipeInputFormTrait {
    
    /**
     * Generates a tree of form elements for a recipe's inputs.
     *
     * @param \Drupal\Core\Recipe\Recipe $recipe
     *   A recipe.
     *
     * @return array[]
     *   A nested array of form elements for collecting input values for the given
     *   recipe and its dependencies. The elements will be grouped by the recipe
     *   that defined the input -- for example, $return['recipe_name']['input1'],
     *   $return['recipe_name']['input2'], $return['dependency']['input_name'],
     *   and so forth. The returned array will have the `#tree` property set to
     *   TRUE.
     */
    protected function buildRecipeInputForm(Recipe $recipe) : array {
        $collector = new class  implements InputCollectorInterface {
            
            /**
             * A form array containing the input elements for the given recipe.
             *
             * This will be a tree of input elements, grouped by the name of the
             * recipe that defines them. For example:
             *
             * @code
             * $form = [
             *   'recipe_1' => [
             *     'input_1' => [
             *       '#type' => 'textfield',
             *       '#title' => 'Some input value',
             *     ],
             *     'input_2' => [
             *       '#type' => 'checkbox',
             *       '#title' => 'Enable some feature or other?',
             *     ],
             *   ],
             *   'dependency_recipe' => [
             *     'input_1' => [
             *       '#type' => 'textarea',
             *       '#title' => 'An input defined by a dependency of recipe_1',
             *     ],
             *   ],
             *   '#tree' => TRUE,
             * ];
             * @endcode
             *
             * The `#tree` property will always be set to TRUE.
             *
             * @var array
             */
            // phpcs:ignore DrupalPractice.CodeAnalysis.VariableAnalysis.UnusedVariable
            public array $form = [];
            
            /**
             * {@inheritdoc}
             */
            public function collectValue(string $name, DataDefinitionInterface $definition, mixed $default_value) : mixed {
                $element = $definition->getSetting('form');
                if ($element) {
                    $element += [
                        '#description' => $definition->getDescription(),
                        '#default_value' => $default_value,
                    ];
                    // Recipe inputs are always required.
                    $element['#required'] = TRUE;
                    NestedArray::setValue($this->form, explode('.', $name, 2), $element);
                    // Always return the input elements as a tree.
                    $this->form['#tree'] = TRUE;
                }
                return $default_value;
            }

};
        $recipe->input
            ->collectAll($collector);
        return $collector->form;
    }
    
    /**
     * Validates user-inputted values to a recipe and its dependencies.
     *
     * @param \Drupal\Core\Recipe\Recipe $recipe
     *   A recipe.
     * @param array $form
     *   The form being validated, which should include the tree of elements
     *   returned by ::buildRecipeInputForm().
     * @param \Drupal\Core\Form\FormStateInterface $form_state
     *   The current form state. The values should be organized in the tree
     *   structure that was returned by ::buildRecipeInputForm().
     */
    protected function validateRecipeInput(Recipe $recipe, array &$form, FormStateInterface $form_state) : void {
        try {
            $this->setRecipeInput($recipe, $form_state);
        } catch (ValidationFailedException $e) {
            $data = $e->getValue();
            if ($data instanceof TypedDataInterface) {
                $element = NestedArray::getValue($form, explode('.', $data->getName(), 2));
                $form_state->setError($element, $e->getMessage());
            }
            else {
                // If the data isn't a typed data object, we have no idea how to handle
                // the situation, so just re-throw the exception.
                throw $e;
            }
        }
    }
    
    /**
     * Supplies user-inputted values to a recipe and its dependencies.
     *
     * @param \Drupal\Core\Recipe\Recipe $recipe
     *   A recipe.
     * @param \Drupal\Core\Form\FormStateInterface $form_state
     *   The current form state. The values should be organized in the tree
     *   structure that was returned by ::buildRecipeInputForm().
     */
    protected function setRecipeInput(Recipe $recipe, FormStateInterface $form_state) : void {
        $recipe->input
            ->collectAll(new class ($form_state) implements InputCollectorInterface {
            public function __construct(FormStateInterface $formState) {
            }
            
            /**
             * {@inheritdoc}
             */
            public function collectValue(string $name, DataDefinitionInterface $definition, mixed $default_value) : mixed {
                return $this->formState
                    ->getValue(explode('.', $name, 2), $default_value);
            }

});
    }

}