Thinkphp之依赖注入

// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006~2018 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------

namespace think;

use Closure;
use InvalidArgumentException;
use ReflectionClass;
use ReflectionFunction;
use ReflectionMethod;

class Container
{
    /**
     * 容器对象实例
     * @var Container
     */
    protected static $instance;

    /**
     * 容器中的对象实例
     * @var array
     */
    protected $instances = [];

    /**
     * 容器绑定标识
     * @var array
     */
    protected $bind = [];

    /**
     * 获取当前容器的实例（单例）
     * @access public
     * @return static
     */
    public static function getInstance()
    {
        if (is_null(static::$instance)) {
            static::$instance = new static;
        }

        return static::$instance;
    }

    /**
     * 获取容器中的对象实例
     * @access public
     * @param  string        $abstract       类名或者标识
     * @param  array|true    $vars           变量
     * @param  bool          $newInstance    是否每次创建新的实例
     * @return object
     */
    public static function get($abstract, $vars = [], $newInstance = false)
    {
        return static::getInstance()->make($abstract, $vars, $newInstance);
    }

    /**
     * 绑定一个类、闭包、实例、接口实现到容器
     * @access public
     * @param  string  $abstract    类标识、接口
     * @param  mixed   $concrete    要绑定的类、闭包或者实例
     * @return Container
     */
    public static function set($abstract, $concrete = null)
    {
        return static::getInstance()->bind($abstract, $concrete);
    }

    /**
     * 绑定一个类、闭包、实例、接口实现到容器
     * @access public
     * @param  string|array  $abstract    类标识、接口
     * @param  mixed         $concrete    要绑定的类、闭包或者实例
     * @return $this
     */
    public function bind($abstract, $concrete = null)
    {
        if (is_array($abstract)) {
            $this->bind = array_merge($this->bind, $abstract);
        } elseif ($concrete instanceof Closure) {
            $this->bind[$abstract] = $concrete;
        } elseif (is_object($concrete)) {
            $this->instances[$abstract] = $concrete;
        } else {
            $this->bind[$abstract] = $concrete;
        }

        return $this;
    }

    /**
     * 绑定一个类实例当容器
     * @access public
     * @param  string    $abstract    类名或者标识
     * @param  object    $instance    类的实例
     * @return $this
     */
    public function instance($abstract, $instance)
    {
        if (isset($this->bind[$abstract])) {
            $abstract = $this->bind[$abstract];
        }

        $this->instances[$abstract] = $instance;

        return $this;
    }

    /**
     * 判断容器中是否存在类及标识
     * @access public
     * @param  string    $abstract    类名或者标识
     * @return bool
     */
    public function bound($abstract)
    {
        return isset($this->bind[$abstract]) || isset($this->instances[$abstract]);
    }

    /**
     * 判断容器中是否存在类及标识
     * @access public
     * @param  string    $name    类名或者标识
     * @return bool
     */
    public function has($name)
    {
        return $this->bound($name);
    }

    /**
     * 创建类的实例
     * @access public
     * @param  string        $abstract       类名或者标识
     * @param  array|true    $args           变量
     * @param  bool          $newInstance    是否每次创建新的实例
     * @return object
     */
    public function make($abstract, $vars = [], $newInstance = false)
    {
        if (true === $vars) {
            // 总是创建新的实例化对象
            $newInstance = true;
            $vars        = [];
        }

        if (isset($this->instances[$abstract]) && !$newInstance) {
            $object = $this->instances[$abstract];
        } else {
            if (isset($this->bind[$abstract])) {
                $concrete = $this->bind[$abstract];

                if ($concrete instanceof Closure) {
                    $object = $this->invokeFunction($concrete, $vars);
                } else {
                    $object = $this->make($concrete, $vars, $newInstance);
                }
            } else {
                $object = $this->invokeClass($abstract, $vars);
            }

            if (!$newInstance) {
                $this->instances[$abstract] = $object;
            }
        }

        return $object;
    }

    /**
     * 执行函数或者闭包方法 支持参数调用
     * @access public
     * @param  string|array|\Closure $function 函数或者闭包
     * @param  array                 $vars     变量
     * @return mixed
     */
    public function invokeFunction($function, $vars = [])
    {
        $reflect = new ReflectionFunction($function);
        $args    = $this->bindParams($reflect, $vars);

        return $reflect->invokeArgs($args);
    }

    /**
     * 调用反射执行类的方法 支持参数绑定
     * @access public
     * @param  string|array $method 方法
     * @param  array        $vars   变量
     * @return mixed
     */
    public function invokeMethod($method, $vars = [])
    {
        if (is_array($method)) {
            $class   = is_object($method[0]) ? $method[0] : $this->invokeClass($method[0]);
            $reflect = new ReflectionMethod($class, $method[1]);
        } else {
            // 静态方法
            $reflect = new ReflectionMethod($method);
        }

        $args = $this->bindParams($reflect, $vars);

        return $reflect->invokeArgs(isset($class) ? $class : null, $args);
    }

    /**
     * 调用反射执行callable 支持参数绑定
     * @access public
     * @param  mixed $callable
     * @param  array $vars   变量
     * @return mixed
     */
    public function invoke($callable, $vars = [])
    {
        if ($callable instanceof Closure) {
            $result = $this->invokeFunction($callable, $vars);
        } else {
            $result = $this->invokeMethod($callable, $vars);
        }

        return $result;
    }

    /**
     * 调用反射执行类的实例化 支持依赖注入
     * @access public
     * @param  string    $class 类名
     * @param  array     $vars  变量
     * @return mixed
     */
    public function invokeClass($class, $vars = [])
    {
        $reflect     = new ReflectionClass($class);
        $constructor = $reflect->getConstructor();

        if ($constructor) {
            $args = $this->bindParams($constructor, $vars);
        } else {
            $args = [];
        }

        return $reflect->newInstanceArgs($args);
    }

    /**
     * 绑定参数
     * @access protected
     * @param  \ReflectionMethod|\ReflectionFunction $reflect 反射类
     * @param  array                                 $vars    变量
     * @return array
     */
    protected function bindParams($reflect, $vars = [])
    {
        $args = [];

        if ($reflect->getNumberOfParameters() > 0) {
            // 判断数组类型 数字数组时按顺序绑定参数
            reset($vars);
            $type   = key($vars) === 0 ? 1 : 0;
            $params = $reflect->getParameters();

            foreach ($params as $param) {
                $name  = $param->getName();
                $class = $param->getClass();

                if ($class) {
                    $className = $class->getName();
                    $args[]    = $this->make($className);
                } elseif (1 == $type && !empty($vars)) {
                    $args[] = array_shift($vars);
                } elseif (0 == $type && isset($vars[$name])) {
                    $args[] = $vars[$name];
                } elseif ($param->isDefaultValueAvailable()) {
                    $args[] = $param->getDefaultValue();
                } else {
                    throw new InvalidArgumentException('method param miss:' . $name);
                }
            }
        }

        return $args;
    }

}