一文理解和实现现代PHP框架里的IOC容器

<?php
class Sunny{
}
$sunny = new Sunny();

<?php
class Sunny{
}
$sunny = Container::getBean(Sunny::class);

<?php
class Computer{
    public function run(){
        echo "编程中....\n";
    }
}
class Sunny{
    private $computer;
    public function __construct(Computer $computer){
        $this->computer = $computer;
    }
    public function program(){
        $this->computer->run();
    }
}
$sunny = new Sunny(new Computer());
$sunny->program();

<?php
class Computer{
    public function run(){
        echo "编程中....\n";
    }
}
class Sunny{
    private $computer;
    public function __construct(Computer $computer){
        $this->computer = $computer;
    }
    public function program(){
        $this->computer->run();
    }
}
$sunny = Container::getBean(Sunny::class);
$sunny->program();

class Cache{
    public function set($key,$value){
        $Redis = new CFile();
        $redis->set($key,$value);
    }
}
class CFile{
    public function set($key,$value){
        echo "file:{$key}->{$value}\n";
    }
}
$cache = new Cache();
$cache->set("name","sunny");

class Cache{
    public function set($key,$value){
        $redis = new CRedis();
        $redis->set($key,$value);
    }
}
class CRedis{
    public function set($key,$value){
        echo "redis:{$key}->{$value}\n";
    }
}
$cache = new Cache();
$cache->set("name","sunny");

interface ICache{
    public function set($key,$value);
}
class CRedis implements ICache {
    public function set($key,$value)
{
        echo "redis:{$key}->{$value}\n";
    }
}
class CFile implements ICache{
    public function set($key,$value)
{
        echo "file:{$key}->{$value}\n";
    }
}
class Cache{
    private $drive;
    public function __construct(ICache $drive)
{
        $this->drive = $drive;
    }
    public function set($key,$value){
        $this->drive->set($key,$value);
    }
}
$cache = new Cache(new CFile());
$cache->set("name","sunny");

<?php
class Container
{
    // 当前容器对象
    private static $instance;
    // 存放在容器里面到实例
    protected $instances = [];
    private function __construct()
{
    }
    public static function getInstance()
{
        if (!self::$instance) {
            self::$instance = new static();
        }
        return self::$instance;
    }
    
    public function get($key)
{
        if (isset($this->instances[$key])) {
            return $this->instances[$key];
        }
    }
    
    public function bind($key, $concrete = null)
{
        if ($concrete instanceof Closure) {
            $this->instances[$key] = $concrete;
        } elseif (is_object($concrete)) {
            $this->instances[$key] = $concrete;
        }
        return $this;
    }
}
class Sunny
{
    public function getName()
{
        echo time() . "\n";
    }
}
$app = Container::getInstance();
$sunny = $app->bind(Sunny::class,new Sunny());
$sunny = $app->get(Sunny::class);
$sunny->getName();

Container.php
<?php
class Container
{
    // 当前容器对象
    private static $instance;
    // 存放在容器里面到实例
    protected $instances = [];
    private function __construct()
{
    }
    public static function getInstance()
{
        if (!self::$instance) {
            self::$instance = new static();
        }
        return self::$instance;
    }
    
    public function get($key)
{
        if (isset($this->instances[$key])) {
            return $this->instances[$key];
        }
        return $this->make($key);
    }
    
    public function bind($key, $concrete = null)
{
        if ($concrete instanceof Closure) {
            $this->instances[$key] = $concrete;
        } elseif (is_object($concrete)) {
            $this->instances[$key] = $concrete;
        } else {
            $this->make($key, $concrete);
        }
        return $this;
    }
    
    public function make($abstract, $atgs = null)
{
        if (isset($this->instances[$abstract])) {
            return $this->instances[$abstract];
        }
        $object = $this->invokeClass($abstract);
        $this->instances[$abstract] = $object;
        return $object;
    }
    
    public function invokeClass($abstract)
{
        $reflectionClass = new \ReflectionClass($abstract);
        // 获取构造方法
        $construct = $reflectionClass->getConstructor();
        // 获取参数得到实例
        $params = $construct ? $this->parserParams($construct) : [];
        $object = $reflectionClass->newInstanceArgs($params);
        return $object;
    }
    
    public function parserParams(ReflectionMethod $reflect)
{
        $args = [];
        $params = $reflect->getParameters();
        if (!$params) {
            return $args;
        }
        if (count($params) > 0) {
            foreach ($params as $param) {
                $class = $param->getClass();
                if ($class) {
                    $args[] = $this->make($class->getName());
                    continue;
                }
                // 获取变量的名称
                $name = $param->getName();
                // 默认值
                $def = null;
                // 如果有默认值，从默认值获取类型
                if ($param->isOptional()) {
                    $def = $param->getDefaultValue();
                }
                $args[] = $_REQUEST[$name] ?? $def;
            }
        }
        return $args;
    }
}
Test.php
<?php
class Test
{
    public $name;
    private $test1;
    public function __construct(Test1 $test1)
{
        $this->test1 = $test1;
        $this->name = $this->test1->getName();
    }
}
Test1.php
<?php
class Test1
{
    public function getName(){
        return "test1返回的名字";
    }
}
Sunny.php
<?php
require_once "./Container.php";
require_once "./Test.php";
require_once "./Test1.php";
class Sunny
{
    private $test;
    public function __construct(Test $test)
{
        $this->test = $test;
    }
    public function getName()
{
        echo "获取test里面的name：{$this->test->name}\n";
    }
}
$app = Container::getInstance();
$sunny = $app->get(Sunny::class);
$sunny->getName();