Elgg_Party.php

<?php

namespace Elgg;

/**
 * Represents a party acting as the subject or object of an action on a site, not necessarily a logged in user.
 *
 * Unlike \ElggUser, a party may represent an anonymous (logged out) user.
 */
class Party {

	/**
	 * @var int
	 */
	private $guid;

	/**
	 * Does this party represent an anonymous logged out user
	 *
	 * @return bool
	 */
	public function isAnonymous() {
		return $this->guid === 0;
	}

	/**
	 * Get the party's GUID (or 0 for anonymous)
	 *
	 * @return int
	 */
	public function getGuid() {
		return $this->guid;
	}

	/**
	 * Get a party representing the current session
	 *
	 * @return Party
	 */
	public static function fromSession() {
		return new self(_elgg_services()->session->getLoggedInUserGuid());
	}

	/**
	 * Build from a given GUID/user entity value
	 *
	 * @param Party|int|\ElggUser $value         A value given to represent a user or GUID
	 * @param bool                $falsy_unknown If true, a falsy value will result in pulling the user GUID
	 *                                           from the current session
	 *
	 * @return Party
	 * @throws \InvalidArgumentException
	 */
	public static function fromValue($value, $falsy_unknown = true) {
		if ($value instanceof Party) {
			return $value;
		}
		if ($value instanceof \ElggUser) {
			return new self($value->guid);
		}
		if (!$value) {
			if ($falsy_unknown) {
				return self::fromSession();
			} else {
				return new self(0);
			}
		}
		if (is_numeric($value)) {
			return new self((int)$value);
		}

		throw new \InvalidArgumentException();
	}

	/**
	 * Constructor
	 *
	 * @param int $guid User GUID or 0 for anonymous
	 */
	private function __construct($guid) {
		$this->guid = (int)$guid;
	}
}