Composer 없이 PSR-4로 Autoload 구현하기

autoload.php

<?php
/**
 * Autoload based on PSR-4
 *
 * 완전한 클래스명으로 인스턴스를 생성하기 위해 Include.
 *
 * 완전한 클래스명 (Fully qualified class name)
 * \<NamespaceName>(\<SubNamespaceNames>)*\<ClassName>
 *
 */

require_once __DIR__ . '/autoload/AutoloadClass.php';

$oLoader = new MoveOpn\Vendor\Autoload\AutoloadClass();

$aMap = require __DIR__ . '/autoload/AutoloadMap.php';

foreach ($aMap as $sNamespace => $sPath) {
    $oLoader->addNamespace($sNamespace, $sPath);
}

$oLoader->register();

AutoloadClass.php

<?php
namespace Moveopn\Vendor\Autoload;

/**
 * An example of a general-purpose implementation that includes the optional
 * functionality of allowing multiple base directories for a single namespace
 * prefix.
 *
 * Given a foo-bar package of classes in the file system at the following
 * paths ...
 *
 *     /path/to/packages/foo-bar/
 *         src/
 *             Baz.php             # Foo\Bar\Baz
 *             Qux/
 *                 Quux.php        # Foo\Bar\Qux\Quux
 *         tests/
 *             BazTest.php         # Foo\Bar\BazTest
 *             Qux/
 *                 QuuxTest.php    # Foo\Bar\Qux\QuuxTest
 *
 * ... add the path to the class files for the \Foo\Bar\ namespace prefix
 * as follows:
 *
 *      <?php
 *      // instantiate the loader
 *      $loader = new \Example\Psr4AutoloaderClass;
 *
 *      // register the autoloader
 *      $loader->register();
 *
 *      // register the base directories for the namespace prefix
 *      $loader->addNamespace('Foo\Bar', '/path/to/packages/foo-bar/src');
 *      $loader->addNamespace('Foo\Bar', '/path/to/packages/foo-bar/tests');
 *
 * The following line would cause the autoloader to attempt to load the
 * \Foo\Bar\Qux\Quux class from /path/to/packages/foo-bar/src/Qux/Quux.php:
 *
 *      <?php
 *      new \Foo\Bar\Qux\Quux;
 *
 * The following line would cause the autoloader to attempt to load the
 * \Foo\Bar\Qux\QuuxTest class from /path/to/packages/foo-bar/tests/Qux/QuuxTest.php:
 *
 *      <?php
 *      new \Foo\Bar\Qux\QuuxTest;
 */
class AutoloadClass
{
    /**
     * An associative array where the key is a namespace prefix and the value
     * is an array of base directories for classes in that namespace.
     *
     * @var array
     */
    protected $prefixes = array();

    /**
     * Register loader with SPL autoloader stack.
     *
     * @return void
     */
    public function register()
    {
        spl_autoload_register(array($this, 'loadClass'));
    }

    /**
     * Adds a base directory for a namespace prefix.
     *
     * @param string $prefix The namespace prefix.
     * @param string $base_dir A base directory for class files in the
     * namespace.
     * @param bool $prepend If true, prepend the base directory to the stack
     * instead of appending it; this causes it to be searched first rather
     * than last.
     * @return void
     */
    public function addNamespace($prefix, $base_dir, $prepend = false)
    {
        // normalize namespace prefix
        $prefix = trim($prefix, '\\') . '\\';

        // normalize the base directory with a trailing separator
        $base_dir = rtrim($base_dir, DIRECTORY_SEPARATOR) . '/';

        // initialize the namespace prefix array
        if (isset($this->prefixes[$prefix]) === false) {
            $this->prefixes[$prefix] = array();
        }

        // retain the base directory for the namespace prefix
        if ($prepend) {
            array_unshift($this->prefixes[$prefix], $base_dir);
        } else {
            array_push($this->prefixes[$prefix], $base_dir);
        }
    }

    /**
     * Loads the class file for a given class name.
     *
     * @param string $class The fully-qualified class name.
     * @return mixed The mapped file name on success, or boolean false on
     * failure.
     */
    public function loadClass($class)
    {
        // the current namespace prefix
        $prefix = $class;

        // work backwards through the namespace names of the fully-qualified
        // class name to find a mapped file name
        while (false !== $pos = strrpos($prefix, '\\')) {

            // retain the trailing namespace separator in the prefix
            $prefix = substr($class, 0, $pos + 1);

            // the rest is the relative class name
            $relative_class = substr($class, $pos + 1);

            // try to load a mapped file for the prefix and relative class
            $mapped_file = $this->loadMappedFile($prefix, $relative_class);
            if ($mapped_file) {
                return $mapped_file;
            }

            // remove the trailing namespace separator for the next iteration
            // of strrpos()
            $prefix = rtrim($prefix, '\\');
        }

        // never found a mapped file
        return false;
    }

    /**
     * Load the mapped file for a namespace prefix and relative class.
     *
     * @param string $prefix The namespace prefix.
     * @param string $relative_class The relative class name.
     * @return mixed Boolean false if no mapped file can be loaded, or the
     * name of the mapped file that was loaded.
     */
    protected function loadMappedFile($prefix, $relative_class)
    {
        // are there any base directories for this namespace prefix?
        if (isset($this->prefixes[$prefix]) === false) {
            return false;
        }

        // look through base directories for this namespace prefix
        foreach ($this->prefixes[$prefix] as $base_dir) {

            // replace the namespace prefix with the base directory,
            // replace namespace separators with directory separators
            // in the relative class name, append with .php
            $file = $base_dir
                . str_replace('\\', '/', $relative_class)
                . '.php';

            // if the mapped file exists, require it
            if ($this->requireFile($file)) {
                // yes, we're done
                return $file;
            }
        }

        // never found it
        return false;
    }

    /**
     * If a file exists, require it from the file system.
     *
     * @param string $file The file to require.
     * @return bool True if the file exists, false if not.
     */
    protected function requireFile($file)
    {
        if (file_exists($file)) {
            require $file;
            return true;
        }
        return false;
    }
}

AutoloadMap.php

<?php
/**
 * autoload_classmap.php
 *
 * Autoload 시킬 대상에 대한 맵핑 정보
 *
 * @return array KEY: prefix, VALUE: base directory
 */

$sBaseDir = dirname(dirname(__DIR__));

return array(
        // Key 는 prefix, Value 는 Base directory
        '\Moveopn\App' => $sBaseDir.'/app',
        '\Moveopn\Core' => $sBaseDir.'/core',
        '\Moveopn\Core\Deprecated' => $sBaseDir.'/core/deprecated',
        '\Moveopn\Lib' => $sBaseDir.'/lib',
        '\Moveopn\Vendor' => $sBaseDir.'/vendor',
        '\Moveopn\Tests' => $sBaseDir.'/tests'

);

REAME.md

├── app
│   ├── migration
│   │   ├── AppMigrationBoard.php
│   │   ├── AppMigrationMember.php
│   │   ├── AppMigrationOrder.php
│   │   ├── AppMigrationProduct.php
............
....중략....
............
├── tests
│   ├── app
│   ├── bootstrap.php
│   ├── core
│   └── lib
└── vendor
    ├── autoload
    │   ├── AutoloadClass.php
    │   └── AutoloadMap.php
    ├── autoload.php
    └── phpunit.phar

아직 Composer를 도입하기 전이라 PSR-4 규칙으로 autoload를 구현했습니다.

http://www.php-fig.org/psr/psr-4/examples/

위 링크에서 제공하는 예제중에 "Class Example"를 토씨하나 안틀리고 가져다 쓴 클래스가 AutoloadClass.php 입니다.
네임스페이스의 prefix와 base directory는 AutoloadMap.php에 배열로 명시되어 있고, 자동으로 autoload 되는 것보다 성능향상이 됩니다.

오토로드를 사용할 php 파일들에서는 autoload.php 만 require_once 하면 됩니다.
이 autoload.php에서는 AutoloadClass와 AutoloadMap.php을 require 하고, 아래의 동작을 수행합니다.

• AutoloadMap의 클래스 맵핑 정보 로드
• 어떤 클래스가 인스턴스화 될때 spl_autoload_register()로 인해서 콜백함수가 호출됨(AutoloadClass클래스의 loadClass 메소드)