Adding ClassLoader with unit tests.

recess/recess/core/ClassLoader.class.php

@@ -0,0 +1,123 @@
+<?php
+namespace recess\core;
+
+require __DIR__.'/Event.class.php';
+require __DIR__.'/Candy.class.php';
+
+/**
+ * ClassLoader is a simple autoloader for including class files. Class files
+ * end with a '.class.php' extension and classes must share the same name as
+ * their containing class file. ClassLoader can be used in conjunction with 
+ * the SPL autoloader chain. Its load function can be candied and wrapped 
+ * with wrapLoad(). After successfully loading a class it will trigger the 
+ * onLoad event.
+ * 
+ * Usage:
+ * spl_autoload_register(array('recess\core\ClassLoader','load'));
+ * use recess\core\ClassLoader;
+ * // Register a call back with the onLoad Event
+ * ClassLoader::onLoad()->call(function($class) { echo "$class loaded! "; });
+ * // Wrap the candied loader
+ * ClassLoader::wrapLoad(
+ *   function($load, $class) {
+ *     echo "Before load $class!";
+ *     $load($class);
+ *     echo "After load $class!";
+ *   }
+ * );
+ * // Load a class explicitely
+ * ClassLoader::load('a\Class');
+ * // Output: Before load A\Class! A\Class loaded! After load A\Class!
+ * // Load a class implicitly
+ * use some\Class;
+ * $someClass = new Class;
+ * // Output: Before load some\Class! some\Class loaded! After load some\Class!
+ * 
+ * @author Kris Jordan <krisjordan@gmail.com>
+ * @since Recess 5.3
+ * @copyright RecessFramework.org 2009
+ * @license MIT
+ */
+abstract class ClassLoader {
+
+	/**
+	 * @var string
+	 */
+	public static $extension = '.class.php';
+
+	/**
+	 * @var recess\core\Event
+	 */
+	private static $onLoad = null;
+
+	/**
+	 * @var recess\core\Candy or \Closure
+	 */
+	private static $loader = null;
+
+	/**
+	 * Returns a reference to the onLoad Event for interested parties
+	 * to register callbacks with.
+	 * @return recess\core\Event
+	 */
+	static public function onLoad() {
+		if(self::$onLoad === null) {
+			self::$onLoad = new Event();
+		}
+		return self::$onLoad;
+	}
+
+	/**
+	 * Load a class by passing a fully qualified classname.
+	 * @param $class string fully qualified classname
+	 * @return bool
+	 */
+	static public function load($class) {
+		if(self::$loader === null) {
+			$loader = self::loader();
+		} else {
+			$loader = self::$loader;
+		}
+		return $loader($class);
+	}
+
+	/**
+	 * Load is candied and can be wrapped by passing a wrapper to this method.
+	 * The wrapper should have two parameters: $load and $class. Usage:
+	 * 
+	 * ClassLoader::wrapLoad(function($load,$class) { echo "loading $class"; $load($class); });
+	 * 
+	 * @param $wrapper
+	 * @return recess\core\Candy
+	 */
+	static public function wrapLoad($wrapper) {
+		if(self::$loader === null) {
+			self::$loader = new Candy(self::loader());
+		}
+		if(!self::$loader instanceof Candy) {
+			self::$loader = new Candy(self::$loader);
+		}
+		return self::$loader->wrap($wrapper);
+	}
+
+	/**
+	 * Returns a closure for loading class files.
+	 * 
+	 * @return \Closure
+	 */
+	static private function loader() {
+		if(self::$loader === null) {
+			$onLoad = self::onLoad();
+			$extension = self::$extension;
+			self::$loader = function($class) use (&$onLoad, &$extension) {
+				if(!class_exists($class)) {
+					$classFile = str_replace('\\','/',$class).$extension;
+					include $classFile;
+					$onLoad($class);
+				}
+				return true;
+			};
+		}		
+		return self::$loader;
+	}
+}

recess/test/recess/core/ClassLoaderTest.php

@@ -0,0 +1,59 @@
+<?php
+require_once 'PHPUnit/Framework.php';
+
+include_once __DIR__ . '/../../../recess/core/ClassLoader.class.php';
+use recess\core\ClassLoader;
+
+class ClassLoaderTest extends PHPUnit_Framework_TestCase {
+
+	function testOnLoad() {
+		$onLoad = ClassLoader::onLoad();
+		$this->assertType('recess\core\Event',$onLoad);
+		$onLoad2 = ClassLoader::onLoad();
+		$this->assertTrue($onLoad === $onLoad2);
+		$theClass = '';
+		ClassLoader::onLoad()->call(function($class) use (&$theClass) { $theClass = $class; });
+		ClassLoader::load('recess\core\Dummy');
+		$this->assertEquals('recess\core\Dummy',$theClass);
+	}
+
+	function testWrapLoad() {
+		$loadedCount = 0;
+		ClassLoader::wrapLoad(
+			function($load,$class) use (&$loadedCount) {
+				if($load($class)) {
+					$loadedCount += 1;
+				} else {
+					$loadedCount -= 1;
+				}
+			});
+		ClassLoader::load('ClassLoaderTest');
+		ClassLoader::load('ClassLoaderTest');
+		$this->assertEquals(2,$loadedCount);
+	}
+
+	function testLoadDummy() {
+		set_include_path(__DIR__.'/../../');
+		ClassLoader::load('recess\core\Dummy');
+		$dummy = new recess\core\Dummy;
+		$this->assertType('recess\core\Dummy',$dummy);
+		$this->assertEquals('hello world',$dummy->helloWorld());
+	}
+
+	function testWrapAfterLoadDummy() {
+		set_include_path(__DIR__.'/../../');
+		ClassLoader::load('recess\core\Dummy');
+		$loadedCount = 0;
+		ClassLoader::wrapLoad(
+			function($load,$class) use (&$loadedCount) {
+				if($load($class)) {
+					$loadedCount += 1;
+				} else {
+					$loadedCount -= 1;
+				}
+			});
+		ClassLoader::load('ClassLoaderTest');
+		$this->assertEquals(1,$loadedCount);
+	}
+
+}

recess/test/recess/core/Dummy.class.php

@@ -0,0 +1,6 @@
+<?php
+namespace recess\core;
+
+class Dummy {
+	function helloWorld() { return 'hello world'; }
+}

recess/test/recess/core/RecessCoreAllTests.php

@@ -1,5 +1,6 @@
 <?php
 require_once 'PHPUnit/Framework.php';
+require_once 'recess/core/ClassLoaderTest.php';
 require_once 'recess/core/CandyTest.php';
 require_once 'recess/core/EventTest.php';
 
@@ -9,6 +10,7 @@ public static function suite()
     {
         $suite = new PHPUnit_Framework_TestSuite('recess\core');
 
+        $suite->addTestSuite('ClassLoaderTest');
         $suite->addTestSuite('EventTest');
  		$suite->addTestSuite('CandyTest');