silverstripe-frameworktest/code/TestCategory.php

<?php

/**
 * A data type that is related many-many to RelationFieldsTestPage, for testing purposes
 */
class TestCategory extends DataObject {
	static $db = array(
		"Title" => "Varchar",
	);
	static $belongs_many_many = array(
		"RelationPages" => "RelationFieldsTestPage",
	);
	
	/**
	 * Returns a dropdown map of all objects of this class
	 */
	static function map() {
		$categories = DataObject::get('TestCategory');
		if($categories) return $categories->map('ID', 'Title')->toArray();
		else return array();
	}

	function requireDefaultRecords(){
		$class = $this->class;
		if(!DataObject::get_one($class)) {
			foreach(array("A","B","C","D") as $item) {
				$page = new $class();
				$page->Title = "Test Category $item";
				$page->write();
			}
		}
	}

}

?>