Commit 62641b42 authored by Taddeus Kroes's avatar Taddeus Kroes

Simplified Autoloader class into an easy-to-use singleton

parent c7d4d826
......@@ -15,163 +15,138 @@ require_once 'base.php';
*
* Simple example: all classes are located in the 'classes' directory.
* <code>
* $loader = new Autoloader('classes');
* $loader->loadClass('FooBar'); // Includes file 'classes/foo_bar.php'
* $loader = webbasics\Autoloader::getInstance();
* $loader->addDirectory('classes'); // Add "classes" directory to global class path
* $loader->loadClass('FooBar'); // Includes file "classes/FooBar.php"
* </code>
*
* An Autoloader instance can register itself to the SPL autoload stack, so
* The Autoloader instance registers itself to the SPL autoload stack, so
* that explicit 'include' statements for classes are not necessary anymore.
* Applied to the example above:
* Therefore, the call to loadClass() in the example above is not necessary:
* <code>
* $loader = new Autoloader('classes');
* $loader->register();
* $foobar = new FooBar(); // File 'classes/foo_bar.php' is automatically included
* webbasics\Autoloader::getInstance()->addDirectory('classes');
* $foobar = new FooBar(); // File "classes/FooBar.php" is automatically included
* </code>
*
* Namespaces are assumed to indicate subdirectories:
* <code>
* Autoloader::create('classes')->register();
* $bar = new Foo\Bar(); // Includes 'classes/foo/bar.php'
* $baz = new Foo\Bar\Baz(); // Includes 'classes/foo/bar/baz.php'
* webbasics\Autoloader::getInstance()->addDirectory('classes');
* $bar = new foo\Bar(); // Includes "classes/foo/Bar.php"
* $baz = new foo\bar\Baz(); // Includes "classes/foo/bar/Baz.php"
* </code>
*
* Multiple autoloaders can be registered at the same time:
* To load classes within some namespace efficiently, directories can be
* assigned to a root namespace:
* <code>
* <code>
* File structure:
* classes/
* | foo.php // Contains class 'Foo'
* other_classes/
* | bar.php // Contains class 'Bar'
* $loader = webbasics\Autoloader::getInstance();
* $loader->addDirectory('models', 'models');
*
* // File "models/Foo.php"
* namespace models;
* class Foo extends ActiveRecord\Model { ... }
* </code>
* Autoloader::create('classes')->register();
* Autoloader::create('other_classes', true)->register();
* $foo = new Foo(); // Includes 'classes/foo.php'
* $bar = new Bar(); // Includes 'other_classes/bar.php', since 'classes/bar.php' does not exist
* $baz = new Baz(); // Throws a FileNotFoundError, since 'other_classes/baz.php' does not exist
*
* Exception throwing can be enabled in case a class does not exist:
* <code>
* $loader = webbasics\Autoloader::getInstance();
* $loader->addDirectory('classes');
* $loader->setThrowExceptions(true);
*
* try {
* new Foo();
* } catch (webbasics\AutoloadError $e) {
* // "classes/Foo.php" does not exist
* }
* </code>
*
* @package WebBasics
*/
class Autoloader extends Base {
class Autoloader extends Base implements Singleton {
/**
* The root directory to look in.
*
* @var string
* Namespaces mapping to lists of directories.
* @var array
*/
private $root_directory;
private $directories = array('\\' => array());
/**
* The namespace classes in the root directory are expected to be in.
*
* This namespace is removed from the beginning of loaded class names.
*
* @var string
*/
private $root_namespace = '\\';
/**
* Whether to throw an exception when a class file does not exist.
*
* Whether to throw an exception if a class file does not exist.
* @var bool
*/
private $throw_errors;
private $throw_exceptions = false;
/**
* Create a new Autoloader instance.
*
* @param string $root_directory Root directory of the autoloader.
* @param string $root_namespace Root namespace of classes loaded by the autoloader.
* @param bool $throw Whether to throw an exception when a class file does not exist.
* @see Singleton::$instance
*/
function __construct($root_directory, $root_namespace='\\', $throw=false) {
$this->setRootDirectory($root_directory);
$this->setRootNamespace($root_namespace);
$this->setThrowErrors($throw);
}
private static $instance;
/**
* Set whether to throw an exception when a class file does not exist.
*
* @param bool $throw Whether to throw exceptions.
* @see Singleton::getInstance()
*/
function setThrowErrors($throw) {
$this->throw_errors = !!$throw;
static function getInstance() {
if (self::$instance === null)
self::$instance = new self;
return self::$instance;
}
/**
* Whether an exception is thrown when a class file does not exist.
* Create a new Autoloader instance.
*
* @return bool
* Registers the {@link loadClass()} function to the SPL autoload stack.
*/
function getThrowErrors() {
return $this->throw_errors;
private function __construct() {
spl_autoload_register(array($this, 'loadClass'), true);
}
/**
* Set the root directory from which classes are loaded.
* Set whether to throw an exception when a class file does not exist.
*
* @param string $directory The new root directory.
* @param bool $throw Whether to throw exceptions.
*/
function setRootDirectory($directory) {
$this->root_directory = self::pathWithSlash($directory);
function setThrowExceptions($throw) {
$this->throw_exceptions = (bool)$throw;
}
/**
* Get the root directory from which classes are loaded.
* Whether an exception is thrown if a class file does not exist.
*
* @return string
* @return bool
*/
function getRootDirectory() {
return $this->root_directory;
function getThrowExceptions() {
return $this->throw_exceptions;
}
/**
* Set the root namespace that loaded classes are expected to be in.
*
* @param string $namespace The new root namespace.
* Add a new directory to look in while looking for a class within the given namespace.
*/
function setRootNamespace($namespace) {
// Assert that the namespace ends with a backslash
if ($namespace[strlen($namespace) - 1] != '\\')
$namespace .= '\\';
function addDirectory($directory, $namespace='\\') {
$directory = self::pathWithSlash($directory);
$this->root_namespace = $namespace;
}
if ($namespace[0] != '\\')
$namespace = '\\' . $namespace;
/**
* Get the root namespace that loaded classes are expected to be in.
*
* @return string
*/
function getRootNamespace() {
return $this->root_namespace;
}
if (!isset($this->directories[$namespace]))
$this->directories[$namespace] = array();
/**
* Convert a class name to a file name.
*
* Uppercase letters are converted to lowercase and prepended
* by an underscore ('_').
*
* @param string $classname The class name to convert.
* @return string
*/
static function classnameToFilename($classname) {
return strtolower(preg_replace('/(?<=.)([A-Z])/', '_\\1', $classname));
if (!in_array($directory, $this->directories[$namespace]))
$this->directories[$namespace][] = $directory;
}
/**
* Strip the root namespace from the beginning of a class name.
* Strip a namespace from the beginning of a class name.
*
* @param string $namespace The namespace to strip.
* @param string $classname The name of the class to strip the namespace from.
* @return string The stripped class name.
*/
private function stripRootNamespace($classname) {
$begin = substr($classname, 0, strlen($this->root_namespace));
private static function stripNamespace($namespace, $classname) {
if ($namespace != '\\')
$namespace .= '\\';
$begin = substr($classname, 0, strlen($namespace));
if ($begin == $this->root_namespace)
$classname = substr($classname, strlen($this->root_namespace));
if ($begin == $namespace)
$classname = substr($classname, strlen($namespace));
return $classname;
}
......@@ -184,16 +159,14 @@ class Autoloader extends Base {
*
* @param string $classname The name of the class to create the file path of.
*/
function createPath($classname) {
$namespaces = array_filter(explode('\\', $classname));
$dirs = array_map('self::classnameToFilename', $namespaces);
$path = $this->root_directory;
private static function createPath($classname) {
$parts = array_filter(explode('\\', $classname));
$path = '';
if (count($dirs) > 1)
$path .= implode('/', array_slice($dirs, 0, count($dirs) - 1)).'/';
if (count($parts) > 1)
$path .= implode('/', array_slice($parts, 0, count($parts) - 1)) . '/';
$path .= end($dirs).'.php';
return strtolower($path);
return $path . end($parts) . '.php';
}
/**
......@@ -203,33 +176,50 @@ class Autoloader extends Base {
* namespace levels are used to indicate directory names.
*
* @param string $classname The name of the class to load, including pepended namespace.
* @param bool $throw Whether to throw an exception if the class file does not exist.
* @return bool
* @throws FileNotFoundError If the class file does not exist.
*/
function loadClass($classname, $throw=null) {
$classname = $this->stripRootNamespace($classname);
$path = $this->createPath($classname);
* @return bool Whether the class file could be found.
* @throws ClassNotFoundError If the class file does not exist.
* @todo Unit test reverse-order namespace traversal
*/
function loadClass($classname) {
// Prepend at least the root namespace
if ($classname[0] != '\\')
$classname = '\\' . $classname;
// Find namespace directory
$parts = array_filter(explode('\\', $classname));
// Try larger namespaces first, getting smaller and smaller up to the global namespace
for ($i = count($parts); $i >= 0; $i--) {
$namespace = '\\' . implode('\\', array_slice($parts, 0, $i));
// If the namespace is mapped to a list of directories, attempt to
// load the class file from there
if (isset($this->directories[$namespace])) {
foreach ($this->directories[$namespace] as $directory) {
$class = self::stripNamespace($namespace, $classname);
$path = $directory . self::createPath($class);
if (file_exists($path)) {
require_once $path;
return true;
}
}
}
}
if (!file_exists($path)) {
if ($throw || ($throw === null && $this->throw_errors))
throw new FileNotFoundError($path);
if ($this->throw_exceptions)
throw new ClassNotFoundError($classname);
return false;
}
}
require_once $path;
return true;
}
/**
* Register the autoloader object to the SPL autoload stack.
*
* @param bool $prepend Whether to prepend the autoloader function to
* the stack, instead of appending it.
/**
* Exception, thrown when a class file could not be found.
*/
function register($prepend=false) {
spl_autoload_register(array($this, 'loadClass'), true, $prepend);
class ClassNotFoundError extends FormattedException {
function __construct($classname) {
parent::__construct('could not load class "%s"', $classname);
}
}
......
......@@ -63,7 +63,7 @@ abstract class Base {
* @return string
*/
static function pathWithSlash($directory) {
return $directory[strlen($directory) - 1] == '/' ? $directory : $directory.'/';
return $directory[strlen($directory) - 1] == '/' ? $directory : $directory . '/';
}
}
......
<?php
require_once 'SingletonTestCase.php';
require_once 'autoloader.php';
use webbasics\Autoloader;
define('PATH', 'tests/_files/');
class AutoloaderTest extends PHPUnit_Framework_TestCase {
function setUp() {
$this->autoloader = new Autoloader(PATH);
class AutoloaderTest extends SingletonTestCase {
function getClassName() {
return 'webbasics\Autoloader';
}
function testSetRootNamespace() {
$this->assertAttributeEquals('\\', 'root_namespace', $this->autoloader);
$this->autoloader->setRootNamespace('Foo');
$this->assertAttributeEquals('Foo\\', 'root_namespace', $this->autoloader);
$this->autoloader->setRootNamespace('Foo\\');
$this->assertAttributeEquals('Foo\\', 'root_namespace', $this->autoloader);
function tearDown() {
Autoloader::getInstance()->setThrowExceptions(false);
}
/**
* @depends testSetRootNamespace
*/
function testGetRootNamespace() {
$this->autoloader->setRootNamespace('Foo');
$this->assertEquals($this->autoloader->getRootNamespace(), 'Foo\\');
function testStripNamespace() {
$rmethod = new ReflectionMethod('webbasics\Autoloader', 'stripNamespace');
$rmethod->setAccessible(true);
$this->assertEquals('Bar', $rmethod->invoke(null, 'foo', 'foo\Bar'));
$this->assertEquals('Bar', $rmethod->invoke(null, '\foo', '\foo\Bar'));
}
/**
* @depends testSetRootNamespace
*/
function testConstructRootNamespace() {
$autoloader = new Autoloader(PATH, 'Foo');
$this->assertAttributeEquals('Foo\\', 'root_namespace', $autoloader);
}
function testAddDirectory() {
$autoloader = Autoloader::getInstance();
$rprop = new ReflectionProperty($autoloader, 'directories');
$rprop->setAccessible(true);
/**
* @depends testSetRootNamespace
*/
function testStripRootNamespace() {
$strip = new ReflectionMethod('webbasics\Autoloader', 'stripRootNamespace');
$strip->setAccessible(true);
$autoloader->addDirectory(PATH);
$this->assertEquals(array(
'\\' => array(PATH)
), $rprop->getValue($autoloader));
$this->autoloader->setRootNamespace('Foo');
$this->assertEquals($strip->invoke($this->autoloader, 'Foo\Bar'), 'Bar');
}
$autoloader->addDirectory(PATH);
$this->assertEquals(array(
'\\' => array(PATH)
), $rprop->getValue($autoloader));
function testSetRootDirectory() {
$this->autoloader->setRootDirectory('tests');
$this->assertEquals($this->autoloader->getRootDirectory(), 'tests/');
}
$autoloader->addDirectory('foo');
$this->assertEquals(array(
'\\' => array(PATH, 'foo/')
), $rprop->getValue($autoloader));
function testClassnameToFilename() {
$this->assertEquals(Autoloader::classnameToFilename('Foo'), 'foo');
$this->assertEquals(Autoloader::classnameToFilename('FooBar'), 'foo_bar');
$this->assertEquals(Autoloader::classnameToFilename('fooBar'), 'foo_bar');
$this->assertEquals(Autoloader::classnameToFilename('FooBarBaz'), 'foo_bar_baz');
$autoloader->addDirectory('bar');
$this->assertEquals(array(
'\\' => array(PATH, 'foo/', 'bar/')
), $rprop->getValue($autoloader));
$autoloader->addDirectory('foodir', 'foo');
$this->assertEquals(array(
'\\' => array(PATH, 'foo/', 'bar/'),
'\foo' => array('foodir/')
), $rprop->getValue($autoloader));
$autoloader->addDirectory('foobardir', 'foobar');
$this->assertEquals(array(
'\\' => array(PATH, 'foo/', 'bar/'),
'\foo' => array('foodir/'),
'\foobar' => array('foobardir/')
), $rprop->getValue($autoloader));
}
/**
* @depends testClassnameToFilename
*/
function testCreatePath() {
$this->assertEquals($this->autoloader->createPath('Foo'), PATH.'foo.php');
$this->assertEquals($this->autoloader->createPath('\Foo'), PATH.'foo.php');
$this->assertEquals($this->autoloader->createPath('Foo\Bar'), PATH.'foo/bar.php');
$this->assertEquals($this->autoloader->createPath('Foo\Bar\Baz'), PATH.'foo/bar/baz.php');
$this->assertEquals($this->autoloader->createPath('FooBar\Baz'), PATH.'foo_bar/baz.php');
$rmethod = new ReflectionMethod('webbasics\Autoloader', 'createPath');
$rmethod->setAccessible(true);
$this->assertEquals($rmethod->invoke(null, 'Foo'), 'Foo.php');
$this->assertEquals($rmethod->invoke(null, '\Foo'), 'Foo.php');
$this->assertEquals($rmethod->invoke(null, 'foo\Bar'), 'foo/Bar.php');
$this->assertEquals($rmethod->invoke(null, 'foo\Bar\Baz'), 'foo/Bar/Baz.php');
$this->assertEquals($rmethod->invoke(null, 'fooBar\Baz'), 'fooBar/Baz.php');
$this->assertEquals($rmethod->invoke(null, 'foo_bar\Baz'), 'foo_bar/Baz.php');
}
function testThrowErrors() {
$this->assertFalse($this->autoloader->getThrowErrors());
$this->autoloader->setThrowErrors(true);
$this->assertTrue($this->autoloader->getThrowErrors());
function testThrowExceptions() {
$autoloader = Autoloader::getInstance();
$this->assertFalse($autoloader->getThrowExceptions());
$autoloader->setThrowExceptions(true);
$this->assertTrue($autoloader->getThrowExceptions());
}
/**
* @depends testCreatePath
* @depends testThrowErrors
* @depends testThrowExceptions
*/
function testLoadClassNotFound() {
$this->assertFalse($this->autoloader->loadClass('foobar'));
}
/**
* @depends testLoadClassNotFound
* @expectedException webbasics\FileNotFoundError
* @expectedExceptionMessage File "tests/_files/foobar.php" does not exist.
*/
function testLoadClassNotFoundError() {
$this->autoloader->setThrowErrors(true);
$this->autoloader->loadClass('foobar');
$this->assertFalse(Autoloader::getInstance()->loadClass('foobar'));
}
/**
* @depends testLoadClassNotFound
* @expectedException webbasics\FileNotFoundError
* @expectedExceptionMessage File "tests/_files/foobar.php" does not exist.
* @expectedException webbasics\ClassNotFoundError
*/
function testLoadClassNotFoundNoerrorOverwrite() {
$this->autoloader->loadClass('foobar', true);
function testLoadClassNotFoundException() {
$autoloader = Autoloader::getInstance();
$autoloader->setThrowExceptions(true);
$autoloader->loadClass('foobar');
}
/**
* @depends testLoadClassNotFound
*/
function testLoadClassNotFoundErrorOverwrite() {
$this->autoloader->setThrowErrors(true);
$this->assertFalse($this->autoloader->loadClass('foobar', false));
}
/**
* @depends testLoadClassNotFound
*/
function testLoadClass() {
$this->assertTrue($this->autoloader->loadClass('Foo'));
function testLoadClassSuccess() {
$autoloader = Autoloader::getInstance();
$this->assertTrue($autoloader->loadClass('Foo'));
$this->assertTrue(class_exists('Foo', false));
$this->assertTrue($this->autoloader->loadClass('Foo\Bar'));
$this->assertTrue(class_exists('Foo\Bar', false));
}
/**
* @depends testLoadClass
* @depends testStripRootNamespace
*/
function testLoadClassRootNamespace() {
$autoloader = new Autoloader(PATH.'foo');
$autoloader->setRootNamespace('Foo');
$this->assertTrue($autoloader->loadClass('Bar'));
$this->assertTrue($autoloader->loadClass('Foo\Bar'));
$this->assertTrue(class_exists('Foo\Bar', false));
}
/**
* @depends testLoadClass
*/
function testRegister() {
$this->autoloader->register();
$this->assertTrue(class_exists('Baz'));
}
/**
* @depends testRegister
* @depends testThrowErrors
*/
function testRegisterPrepend() {
$second_loader = new Autoloader(PATH.'second');
$this->autoloader->register();
$second_loader->register(true); // Prepend so that the second loader attemps to load Bar first
$this->assertInstanceOf('Foo', new FooBaz());
}
}
?>
\ No newline at end of file
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