dnadesign / silverstripe-elemental

code/models/ElementList.php

<?php

/**
 * A list contains nested {@link BaseElement} such as a list of related files.
 *
 * @package elemental
 */
class ElementList extends BaseElement
{

    private static $db = array(
        'ListDescription' => 'HTMLText'
    );

    private static $has_many = array(
        'Elements' => 'BaseElement'
    );

    private static $duplicate_relations = array(
        'Elements'
    );

    private static $extensions = array(
        'ElementPublishChildren'
    );

    private static $title = "Element List Element";

    private static $description = "Orderable list of elements";

    protected $enable_title_in_template = true;

    public function getCMSFields()
    {
        $elements = $this->Elements();
        $isInDb = $this->isInDB();
        $allowed = $this->config()->get('allowed_elements');

        $this->beforeUpdateCMSFields(function ($fields) use ($elements, $isInDb, $allowed) {
            $desc = HTMLEditorField::create('ListDescription', 'List Description');
            $desc->setRightTitle('Optional');
            $fields->addFieldToTab('Root.Main', $desc);

            if ($isInDb) {
                $adder = new GridFieldAddNewMultiClass();

                if (is_array($allowed)) {
                    $list = $allowed;
                } else {
                    $classes = ClassInfo::subclassesFor('BaseElement');
                    $list = array();
                    unset($classes['BaseElement']);

                    foreach ($classes as $class) {
                        $list[$class] = singleton($class)->i18n_singular_name();
                    }
                }

                asort($list);

                $adder->setClasses($list);

                $config = GridFieldConfig_RecordEditor::create(100);
                $config->addComponent(new GridFieldSortableRows('Sort'));
                $config->removeComponentsByType('GridFieldAddNewButton');
                $config->addComponent($adder);

                $config->removeComponentsByType('GridFieldDetailForm');
                $config->addComponent(new VersionedDataObjectDetailsForm());

                $widgetArea = new GridField(
                    'Elements',
                    Config::inst()->get("ElementPageExtension", 'elements_title'),
                    $elements,
                    $config
                );

                $fields->addFieldToTab('Root.Main', $widgetArea);
            } else {
                $fields->addFieldToTab('Root.Main', LiteralField::create('warn', '<p class="message notice">Once you save this object you will be able to add items</p>'));
            }

            $fields->removeByName('Root.Elements');
        });

        return parent::getCMSFields();
    }

    /**
     * Used in template instead of {@link Widgets()} to wrap each widget in its
     * controller, making it easier to access and process form logic and
     * actions stored in {@link WidgetController}.
     *
     * @return SS_List - Collection of {@link WidgetController} instances.
     */
    public function WidgetControllers() {
        $controllers = new ArrayList();

        foreach($this->Elements()->filter('Enabled', 1) as $widget) {

The method Elements does not exist on object<ElementList>? Since you implemented __call, maybe consider adding a @method annotation.

            $controller = $widget->getController();

            $controller->init();
            $controllers->push($controller);
        }

        return $controllers;
    }
}