laravel 依赖注入

<?php
 interface  Animal{

     public  function attack();
     public  function talk();

 }

class People implements Animal
{
    public  $month;
    public  $hand;
    public  function __construct(Mouth $mouth,Hand $hand)
    {
        $this->month = $mouth;
        $this->hand  = $hand;

    }

    public  function attack()
    {
        $this->hand->scrap();
    }

    public  function talk()
    {
       $this->month->say();
    }

}

class  Mouth{
    public  function say(){
        echo "咿咿呀呀";
    }
}
class  Hand{
    public  $finger;
    public  function __construct(Finger $finger)
    {
        $this->finger = $finger;
    }

    public  function scrap(){
        echo '仍玩具';
    }

    public  function otherFunction(){
        $this->finger->eatFinger();
    }
}

class Finger{
     public  function eatFinger(){
         echo "吃手指";
     }
}

class Container
{
    /**
     *  容器绑定，用来装提供的实例或者 提供实例的回调函数
     * @var array
     */
    public $building = [];

    /**
     * 注册一个绑定到容器
     */
    public function bind($abstract, $concrete = null, $shared = false){
    if(is_null($concrete)){
        $concrete = $abstract;
    }

    if(!$concrete instanceOf Closure){
        $concrete = $this->getClosure($abstract, $concrete);
    }

    $this->building[$abstract] =  compact("concrete", "shared");
}

    //注册一个共享的绑定 单例
    public function singleton($abstract, $concrete, $shared = true){
    $this->bind($abstract, $concrete, $shared);
}

    /**
     * 默认生成实例的回调闭包
     *
     * @param $abstract
     * @param $concrete
     * @return Closure
     */
    public function getClosure($abstract, $concrete){
    return function($c) use($abstract, $concrete){
        $method = ($abstract == $concrete)? 'build' : 'make';
        return $c->$method($concrete);
    };
}

    /**
     * 生成实例
     */
    public function make($abstract){
    $concrete = $this->getConcrete($abstract);

    if($this->isBuildable($concrete, $abstract)){
        $object = $this->build($concrete);
    }else{
        $object = $this->make($concrete);
    }

    return $object;
}

    /**
     * 获取绑定的回调函数
     */
    public function getConcrete($abstract){

    if(! isset($this->building[$abstract])){
        return $abstract;
    }

    return $this->building[$abstract]['concrete'];
}

    /**
     * 判断 是否 可以创建服务实体
     */
    public function isBuildable($concrete, $abstract){

    return $concrete === $abstract || $concrete instanceof Closure;
    }

    /**
     * 根据实例具体名称实例具体对象
     */
    public function build($concrete){

    if($concrete instanceof Closure){
        return $concrete($this);
    }

    //创建反射对象
    $reflector = new ReflectionClass($concrete);//通过反射获取类名

    if( ! $reflector->isInstantiable()){
        //抛出异常
        throw new \Exception('无法实例化');
    }

    $constructor = $reflector->getConstructor();//获取构造函数
    if(is_null($constructor)){
        return new $concrete;
    }

    $dependencies = $constructor->getParameters();//获取构造函数参数
    $instance = $this->getDependencies($dependencies);
    return $reflector->newInstanceArgs($instance);//将参数注入到对象中

}

    //通过反射解决参数依赖
    public function getDependencies(array $dependencies){
    $results = [];
    foreach( $dependencies as $dependency ){
        $results[] = is_null($dependency->getClass())
            ?$this->resolvedNonClass($dependency)
            :$this->resolvedClass($dependency);
    }

    return $results;
}

    //解决一个没有类型提示依赖
    public function resolvedNonClass(ReflectionParameter $parameter)
    {
    if($parameter->isDefaultValueAvailable()){
        return $parameter->getDefaultValue();
    }
    throw new \Exception('出错');

    }

    //通过容器解决依赖
    public function resolvedClass(ReflectionParameter $parameter)
    {
         return $this->make($parameter->getClass()->name);

    }

}
//实例化容器类
$container =  new Container();
$container->bind('Animal','People');//将需要创建对象的类放到容器中
$people  = $container->make('Animal');//创建对象
$people->attack();//调用方法
$people->talk();
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laravel 依赖注入

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