15.自动加载配置

<?php
namespace IMooc;

class Config implements \ArrayAccess
{
//$path，配置文件所在的目录
protected $path;

//$configs,用来保存已经加载过的配置
protected $configs = array();

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

function offsetGet($key)
{
//先判断这个项是否加载，如果不存在，从文件中加载
if (empty($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

$config = array(
'home' => array(
'decorator' => array(
'IMooc\Decorator\Template',
),
),
'default' => 'hello ,world',
);

return $config;

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