silverstripe-widgets/code/model/WidgetArea.php

<?php

/**
 * Represents a set of widgets shown on a page.
 *
 * @package widgets
 */
class WidgetArea extends DataObject {

	/**
	 * @var array
	 */
	private static $has_many = array(
		"Widgets" => "Widget"
	);

	/**
	 *
	 * @var string
	 */
	public $template = __CLASS__;
	
	/**
	 * 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->ItemsToRender() as $widget) {
			$controller = $widget->getController();

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

		return $controllers;
	}

	/**
	 * @return HasManyList
	 */
	public function Items() {
		return $this->getComponents('Widgets');
	}

	/**
	 * @return HasManyList
	 */
	public function ItemsToRender() {
		return $this->getComponents('Widgets')
			->filter("Enabled", 1);
	}

	/**
	 * @return string - HTML
	 */
	public function forTemplate() {
		return $this->renderWith($this->template); 
	}

	/**
	 *
	 * @param string $template
	 */
	public function setTemplate($template) {
		$this->template = $template;
	}

	/**
	 * Delete all connected Widgets when this WidgetArea gets deleted
	 */
	public function onBeforeDelete() {
		parent::onBeforeDelete();
		foreach($this->Widgets() as $widget) {
			$widget->delete();
		}
	}
}