[TOC]
Last-Modified： 2019年5月10日16:15:36
1. 前言在看了一些容器实现代码后, 就手痒想要自己实现一个, 因此也就有了本文接下来的内容.
首先, 实现的容器需要具有以下几点特性:
符合PSR-11标准实现基本的容器存储功能具有自动依赖解决能力本项目代码由GitHub托管
可使用Composer进行安装 composer require yjx/easy-di
2. 项目代码结构|-src |-Exception |-InstantiateException.php (实现Psr\Container\ContainerExceptionInterface) |-InvalidArgumentException.php (实现Psr\Container\ContainerExceptionInterface) |-UnknownIdentifierException.php (实现Psr\Container\NotFoundExceptionInterface) |-Container.php # 容器|-tests |-UnitTest |-ContainerTest.php3. 容器完整代码代码版本 v1.0.1<?phpnamespace EasyDI;use EasyDI\Exception\UnknownIdentifierException;use EasyDI\Exception\InvalidArgumentException;use EasyDI\Exception\InstantiateException;use Psr\Container\ContainerExceptionInterface;use Psr\Container\ContainerInterface;use Psr\Container\NotFoundExceptionInterface;class Container implements ContainerInterface{ /** * 保存 参数, 已实例化的对象 * @var array */ private $instance = []; private $shared = []; private $raw = []; private $params = []; /** * 保存 定义的 工厂等 * @var array */ private $binding = []; public function __construct() { $this->raw(ContainerInterface::class, $this); $this->raw(self::class, $this); } /** * Finds an entry of the container by its identifier and returns it. * * @param string $id Identifier of the entry to look for. * * @throws NotFoundExceptionInterface No entry was found for **this** identifier. * @throws ContainerExceptionInterface Error while retrieving the entry. * * @return mixed Entry. */ public function get($id, $parameters = [], $shared=false) { if (!$this->has($id)) { throw new UnknownIdentifierException($id); } if (array_key_exists($id, $this->raw)) { return $this->raw[$id]; } if (array_key_exists($id, $this->instance)) { return $this->instance[$id]; } $define = array_key_exists($id, $this->binding) ? $this->binding[$id] : $id; if ($define instanceof \Closure) { $instance = $this->call($define, $parameters); } else { // string $class = $define; $params = (empty($this->params[$id]) ? [] : $this->params[$id]) + $parameters; // Case: "\\xxx\\xxx"=>"abc" if ($id !== $class && $this->has($class)) { $instance = $this->get($class, $params); } else { $dependencies = $this->getClassDependencies($class, $params); if (is_null($dependencies) || empty($dependencies)) { $instance = $this->getReflectionClass($class)->newInstanceWithoutConstructor(); } else { $instance = $this->getReflectionClass($class)->newInstanceArgs($dependencies); } } } if ($shared || (isset($this->shared[$id]) && $this->shared[$id])) { $this->instance[$id] = $instance; } return $instance; } /** * @param callback $function * @param array $parameters * @return mixed * @throws InvalidArgumentException 传入错误的参数 * @throws InstantiateException */ public function call($function, $parameters=[], $shared=false) { //参考 http://php.net/manual/zh/function.call-user-func-array.php#121292 实现解析$function $class = null; $method = null; $object = null; // Case1: function() {} if ($function instanceof \Closure) { $method = $function; } elseif (is_array($function) && count($function)==2) { // Case2: [$object, $methodName] if (is_object($function[0])) { $object = $function[0]; $class = get_class($object); } elseif (is_string($function[0])) { // Case3: [$className, $staticMethodName] $class = $function[0]; } if (is_string($function[1])) { $method = $function[1]; } } elseif (is_string($function) && strpos($function, '::') !== false) { // Case4: "class::staticMethod" list($class, $method) = explode('::', $function); } elseif (is_scalar($function)) { // Case5: "functionName" $method = $function; } else { throw new InvalidArgumentException("Case not allowed! Invalid Data supplied!"); } try { if (!is_null($class) && !is_null($method)) { $reflectionFunc = $this->getReflectionMethod($class, $method); } elseif (!is_null($method)) { $reflectionFunc = $this->getReflectionFunction($method); } else { throw new InvalidArgumentException("class:$class method:$method"); } } catch (\ReflectionException $e) {// var_dump($e->getTraceAsString()); throw new InvalidArgumentException("class:$class method:$method", 0, $e); } $parameters = $this->getFuncDependencies($reflectionFunc, $parameters); if ($reflectionFunc instanceof \ReflectionFunction) { return $reflectionFunc->invokeArgs($parameters); } elseif ($reflectionFunc->isStatic()) { return $reflectionFunc->invokeArgs(null, $parameters); } elseif (!empty($object)) { return $reflectionFunc->invokeArgs($object, $parameters); } elseif (!is_null($class) && $this->has($class)) { $object = $this->get($class, [], $shared); return $reflectionFunc->invokeArgs($object, $parameters); } throw new InvalidArgumentException("class:$class method:$method, unable to invoke."); } /** * @param $class * @param array $parameters * @throws \ReflectionException */ protected function getClassDependencies($class, $parameters=[]) { // 获取类的反射类 $reflectionClass = $this->getReflectionClass($class); if (!$reflectionClass->isInstantiable()) { throw new InstantiateException($class); } // 获取构造函数反射类 $reflectionMethod = $reflectionClass->getConstructor(); if (is_null($reflectionMethod)) { return null; } return $this->getFuncDependencies($reflectionMethod, $parameters, $class); } protected function getFuncDependencies(\ReflectionFunctionAbstract $reflectionFunc, $parameters=[], $class="") { $params = []; // 获取构造函数参数的反射类 $reflectionParameterArr = $reflectionFunc->getParameters(); foreach ($reflectionParameterArr as $reflectionParameter) { $paramName = $reflectionParameter->getName(); $paramPos = $reflectionParameter->getPosition(); $paramClass = $reflectionParameter->getClass(); $context = ['pos'=>$paramPos, 'name'=>$paramName, 'class'=>$paramClass, 'from_class'=>$class]; // 优先考虑 $parameters if (isset($parameters[$paramName]) || isset($parameters[$paramPos])) { $tmpParam = isset($parameters[$paramName]) ? $parameters[$paramName] : $parameters[$paramPos]; if (gettype($tmpParam) == 'object' && !is_a($tmpParam, $paramClass->getName())) { throw new InstantiateException($class."::".$reflectionFunc->getName(), $parameters + ['__context'=>$context, 'tmpParam'=>get_class($tmpParam)]); } $params[] = $tmpParam;// $params[] = isset($parameters[$paramName]) ? $parameters[$paramName] : $parameters[$pos]; } elseif (empty($paramClass)) { // 若参数不是class类型 // 优先使用默认值, 只能用于判断用户定义的函数/方法, 对系统定义的函数/方法无效, 也同样无法获取默认值 if ($reflectionParameter->isDefaultValueAvailable()) { $params[] = $reflectionParameter->getDefaultValue(); } elseif ($reflectionFunc->isUserDefined()) { throw new InstantiateException("UserDefined. ".$class."::".$reflectionFunc->getName()); } elseif ($reflectionParameter->isOptional()) { break; } else { throw new InstantiateException("SystemDefined. ".$class."::".$reflectionFunc->getName()); } } else { // 参数是类类型, 优先考虑解析 if ($this->has($paramClass->getName())) { $params[] = $this->get($paramClass->getName()); } elseif ($reflectionParameter->allowsNull()) { $params[] = null; } else { throw new InstantiateException($class."::".$reflectionFunc->getName()." {$paramClass->getName()} "); } } } return $params; } protected function getReflectionClass($class, $ignoreException=false) { static $cache = []; if (array_key_exists($class, $cache)) { return $cache[$class]; } try { $reflectionClass = new \ReflectionClass($class); } catch (\Exception $e) { if (!$ignoreException) { throw new InstantiateException($class, 0, $e); } $reflectionClass = null; } return $cache[$class] = $reflectionClass; } protected function getReflectionMethod($class, $name) { static $cache = []; if (is_object($class)) { $class = get_class($class); } if (array_key_exists($class, $cache) && array_key_exists($name, $cache[$class])) { return $cache[$class][$name]; } $reflectionFunc = new \ReflectionMethod($class, $name); return $cache[$class][$name] = $reflectionFunc; } protected function getReflectionFunction($name) { static $closureCache; static $cache = []; $isClosure = is_object($name) && $name instanceof \Closure; $isString = is_string($name); if (!$isString && !$isClosure) { throw new InvalidArgumentException("$name can't get reflection func."); } if ($isString && array_key_exists($name, $cache)) { return $cache[$name]; } if ($isClosure) { if (is_null($closureCache)) { $closureCache = new \SplObjectStorage(); } if ($closureCache->contains($name)) { return $closureCache[$name]; } } $reflectionFunc = new \ReflectionFunction($name); if ($isString) { $cache[$name] = $reflectionFunc; } if ($isClosure) { $closureCache->attach($name, $reflectionFunc); } return $reflectionFunc; } /** * Returns true if the container can return an entry for the given identifier. * Returns false otherwise. * * `has($id)` returning true does not mean that `get($id)` will not throw an exception. * It does however mean that `get($id)` will not throw a `NotFoundExceptionInterface`. * * @param string $id Identifier of the entry to look for. * * @return bool */ public function has($id) { $has = array_key_exists($id, $this->binding) || array_key_exists($id, $this->raw) || array_key_exists($id, $this->instance); if (!$has) { $reflectionClass = $this->getReflectionClass($id, true); if (!empty($reflectionClass)) { $has = true; } } return $has; } public function needResolve($id) { return !(array_key_exists($id, $this->raw) && (array_key_exists($id, $this->instance) && $this->shared[$id])); } public function keys() { return array_unique(array_merge(array_keys($this->raw), array_keys($this->binding), array_keys($this->instance))); } public function instanceKeys() { return array_unique(array_keys($this->instance)); } public function unset($id) { unset($this->shared[$id], $this->binding[$id], $this->raw[$id], $this->instance[$id], $this->params[$id]); } public function singleton($id, $value, $params=[]) { $this->set($id, $value, $params, true); } /** * 想好定义数组, 和定义普通项 * @param $id * @param $value * @param bool $shared */ public function set($id, $value, $params=[], $shared=false) { if (is_object($value) && !($value instanceof \Closure)) { $this->raw($id, $value); return; } elseif ($value instanceof \Closure) { // no content } elseif (is_array($value)) { $value = [ 'class' => $id, 'params' => [], 'shared' => $shared ] + $value; if (!isset($value['class'])) { $value['class'] = $id; } $params = $value['params'] + $params; $shared = $value['shared']; $value = $value['class']; } elseif (is_string($value)) { // no content } $this->binding[$id] = $value; $this->shared[$id] = $shared; $this->params[$id] = $params; } public function raw($id, $value) { $this->unset($id); $this->raw[$id] = $value; } public function batchRaw(array $data) { foreach ($data as $key=>$value) { $this->raw($key, $value); } } public function batchSet(array $data, $shared=false) { foreach ($data as $key=>$value) { $this->set($key, $value, $shared); } }}3.1 容器主要提供方法容器提供方法:
...