PHP使用ArrayAccess实现配置文件的加载

<?php
namespace Frame;

class Config implements \ArrayAccess
{
    protected $path;
    protected $configs = array();

    function __construct($path)
    {
        $this->path = $path;
    }

    function offsetGet($key)
    {
        if (empty($this->configs[$key]))
        {
            $file_path = $this->path.'/'.$key.'.php';
            $config = require $file_path;
            $this->configs[$key] = $config;
        }
        return $this->configs[$key];
    }

    function offsetSet($key, $value)
    {
        throw new \Exception("cannot write config file.");
    }

    function offsetExists($key)
    {
        return isset($this->configs[$key]);
    }

    function offsetUnset($key)
    {
        unset($this->configs[$key]);
    }
}

<?php
define('BASEDIR',__DIR__);
include BASEDIR.'/Frame/Loader.php';
spl_autoload_register('\\Frame\\Loader::autoload');

$config = new \Frame\Config(__DIR__.'/configs');
var_dump($config['controller']);die;

<?php
namespace Frame;

class Application
{
    public $base_dir;
    protected static $instance;

    public $config;

    protected function __construct($base_dir)
    {
        $this->base_dir = $base_dir;
        $this->config = new Config($base_dir.'/configs');
    }

    static function getInstance($base_dir = '')
    {
        if (empty(self::$instance))
        {
            self::$instance = new self($base_dir);
        }
        return self::$instance;
    }

    function dispatch()
    {
        $uri = $_SERVER['REQUEST_URI'];
        list($script,$c, $v) = explode('/', trim($uri, '/'));

        $c_low = strtolower($c);
        $c = ucwords($c);
        $class = '\\App\\Controller\\'.$c;
        $obj = new $class($c, $v);

        $controller_config = $this->config['controller'];
        $decorators = array();
        if (isset($controller_config[$c_low]['decorator']))
        {
            $conf_decorator = $controller_config[$c_low]['decorator'];
            foreach($conf_decorator as $class)
            {
                $decorators[] = new $class;
            }
        }
        foreach($decorators as $decorator)
        {
            $decorator->beforeRequest($obj);
        }
        $return_value = $obj->$v();
        foreach($decorators as $decorator)
        {
            $decorator->afterRequest($return_value);
        }
    }
}

<?php
namespace Frame;

class Factory
{
    static $proxy = null;
    /**
     * @param $id
     * @return User
     */
    static function getUser($id)
    {
        $key = 'user_'.$id;
        $user = Register::get($key);
        if (!$user) {
            $user = new User($id);
            Register::set($key, $user);
        }
        return $user;
    }

    /**
     * @param $name
     * @return bool
     */
    static function getModel($name)
    {
        $key = 'app_model_'.$name;
        $model = Register::get($key);
        if (!$model) {
            $class = '\\App\\Model\\'.ucwords($name);//首字母转成大写
            $model = new $class;
            Register::set($key, $model);
        }
        return $model;
    }

    static function getDatabase($id = 'proxy')
    {
        if ($id == 'proxy')
        {
            if (!self::$proxy)
            {
                self::$proxy = new \Frame\Database\Proxy;
            }
            return self::$proxy;
        }

        $key = 'database_'.$id;
        if ($id == 'slave')
        {
            $slaves = Application::getInstance()->config['database']['slave'];
            $db_conf = $slaves[array_rand($slaves)];
        }
        else
        {
            $db_conf = Application::getInstance()->config['database'][$id];
        }
        $db = Register::get($key);
        if (!$db) {
            $db = new Database\MySQLi();
            $db->connect($db_conf['host'], $db_conf['user'], $db_conf['password'], $db_conf['dbname']);
            Register::set($key, $db);
        }
        return $db;
    }
}