Fixed bugs related to #24 such as getName() on null

src/pocketmine/level/Position.php

@@ -64,7 +64,7 @@ class Position extends Vector3{
 	 * @return bool
 	 */
 	public function isValid(){
-		return $this->level !== null;
+		return $this->getLevel() !== null;
 	}
 
 	/**

src/pocketmine/level/WeakPosition.php

@@ -0,0 +1,78 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____  
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \ 
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/ 
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_| 
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ * 
+ *
+*/
+
+namespace pocketmine\level;
+
+use pocketmine\math\Vector3;
+use pocketmine\Server;
+use pocketmine\utils\LevelException;
+
+class WeakPosition extends Position{
+
+	/**
+	 * @param int   $x
+	 * @param int   $y
+	 * @param int   $z
+	 * @param Level $level
+	 */
+	public function __construct($x = 0, $y = 0, $z = 0, Level $level = null){
+		$this->x = $x;
+		$this->y = $y;
+		$this->z = $z;
+		$this->levelId = ($level !== null ? $level->getId() : -1);
+	}
+
+	public static function fromObject(Vector3 $pos, Level $level = null){
+		return new WeakPosition($pos->x, $pos->y, $pos->z, $level);
+	}
+
+	/**
+	 * @return Level
+	 */
+	public function getLevel(){
+		return Server::getInstance()->getLevel($this->levelId);
+	}
+
+	public function setLevel(Level $level){
+		$this->levelId = ($level !== null ? $level->getId() : -1);
+		return $this;
+	}
+
+	/**
+	 * Returns a side Vector
+	 *
+	 * @param int $side
+	 * @param int $step
+	 *
+	 * @return WeakPosition
+	 *
+	 * @throws LevelException
+	 */
+	public function getSide($side, $step = 1){
+		assert($this->isValid());
+
+		return WeakPosition::fromObject(parent::getSide($side, $step), $this->level);
+	}
+
+	public function __toString(){
+		return "Weak" . parent::__toString();
+	}
+}