Page.php

<?php

class Page extends SiteTree {
  
  /**
	 * Return any event pages that are in this section.
	 * @param ArrayList|null $children
	 * @param ArrayList|null &$events
	 * @return ArrayList
	 */
	public function SectionEvents() {
		$top = $this->Level(1);
		$events = ArrayList::create();

		$top->loadChildEventsInto($events);

		return $events;
	}

	/**
	 * Recursively scans child pages looking for instances of 'EventPage' and adding
	 * them to the ArrayList passed by reference
	 * @param ArrayList &$arrayList
	 * @return void
	 */
	protected function loadChildEventsInto(ArrayList &$arrayList) {
		if($children = $this->Children()) {
			foreach($children as $child) {
				if($child->ClassName === 'EventPage') {
					$arrayList->push($child);
				}

				$child->loadChildEventsInto($arrayList);
			}
		}
	}
  
}