Slim
的话，是一个遵循 (PSR-7)规范微型的框架，作者这样说：
Slim is a PHP micro framework that helps you quickly write simple yet powerful web applications and APIs. At its core, Slim is a dispatcher that receives an HTTP request, invokes an appropriate callback routine, and returns an HTTP response. That’s it.
大致意思：slim的核心工作：分发了Http请求，然后调用回调函数，返回一个Http response对象。
Slim其实就帮我们做了两件事
- 路由的分发
- 依赖的注入
框架很小，所以别的部分（如db操作、模板引擎）可能需要自己实现，但slim通过，让你可以很轻松的组装其他功能到slim中。
快速入门：
[ 'addContentLengthHeader' => false,]];$app = new \Slim\App($config);// Define app routes$app->get('/hello/{name}', function ($request, $response, $args) { return $response->write("Hello " . $args['name']);});// Run app$app->run(); request代表了当前请求对象，response代表了当前响应对象，$args是占位符的键值对数组。
访问/hello/salamander就会输出Hello salamander 添加依赖
是我自己封装的一个PDO的操作类。
$config = ['settings' => [ 'addContentLengthHeader' => false,]];$app = new \Slim\App($config);$container = $app->getContainer();$container['db'] = function($c) { $dbHost = 'localhost'; $dbName = 'test'; $dbConf = [ 'dsn' => "mysql:dbname={$dbName};host={$dbHost}", 'username' => "root", 'password' => "******", 'charset' => 'utf8' ]; $db = new \App\Library\DB(); $db->__setup($dbConf); return $db;};// Define app routes$app->get('/user/{uid}', 'App\Controller\IndexController:index'); IndexController类
namespace App\Controller;class IndexController { protected $container; public function __construct(ContainerInterface $container) { $this->container = $container; } public function index($request, $response, $args) { $info = $this->container['db']->fetch('SELECT name FROM user WHERE uid = :uid', [ 'uid' => $args['uid'] ]); echo "user name is " . $info['name']; }} IndexController类的是通过composer自动载入的（代码中没写）：
"autoload": { "psr-4": { "App\\": "app/" }}, 代码中可以发现，依赖容器的注入是在类实例化的时候发生的。执行IndexController的index方法时，我们从$container中取出的db依赖，这时候，注册的回调函数被调用，返回实例。因为是用到时才实例化，这个叫做延迟实例化。
结合Swoole
让PHP可以常驻内存，而且它提供了Http Server的功能，所以Slim和Swoole没什么冲突。
思考
Slim是通过当前路由(譬如/user/2，不带查询字符串)和http方法来找到正确的回调函数的。这些量Slim是从哪里取的呢？肯定是$_SERVER。查看slim源码：
public function run($silent = false){ $response = $this->container->get('response'); try { ob_start(); $response = $this->process($this->container->get('request'), $response); } catch (InvalidMethodException $e) { $response = $this->processInvalidMethod($e->getRequest(), $response); } finally { $output = ob_get_clean(); } if (!empty($output) && $response->getBody()->isWritable()) { $outputBuffering = $this->container->get('settings')['outputBuffering']; if ($outputBuffering === 'prepend') { // prepend output buffer content $body = new Http\Body(fopen('php://temp', 'r+')); $body->write($output . $response->getBody()); $response = $response->withBody($body); } elseif ($outputBuffering === 'append') { // append output buffer content $response->getBody()->write($output); } } $response = $this->finalize($response); if (!$silent) { $this->respond($response); } return $response;} 发现$request对象是从容器取出来的，那$request是怎么注册的呢？？，那就看App类的构造函数了，最后发现Container类的构造函数中有registerDefaultServices()方法：
private function registerDefaultServices($userSettings){ $defaultSettings = $this->defaultSettings; /** * This service MUST return an array or an * instance of \ArrayAccess. * * @return array|\ArrayAccess */ $this['settings'] = function () use ($userSettings, $defaultSettings) { return new Collection(array_merge($defaultSettings, $userSettings)); }; $defaultProvider = new DefaultServicesProvider(); $defaultProvider->register($this);} 查看$defaultProvider->register()方法：
public function register($container){ if (!isset($container['environment'])) { /** * This service MUST return a shared instance * of \Slim\Interfaces\Http\EnvironmentInterface. * * @return EnvironmentInterface */ $container['environment'] = function () { return new Environment($_SERVER); }; } if (!isset($container['request'])) { /** * PSR-7 Request object * * @param Container $container * * @return ServerRequestInterface */ $container['request'] = function ($container) { return Request::createFromEnvironment($container->get('environment')); }; } //... 可以看到$request对象是通过Request::createFromEnvironment方法构造的，它需要从容器中取出environment依赖，而environment依赖是通过构造一个Environment对象得来的，它正好放入了$_SERVER
Collection类，Collection的构造函数如下： public function __construct(array $items = []){ $this->replace($items);} 从上面我们可以得出，我们主要注册一个自定义的environment依赖就行，原来$_SERVER的信息可以从swoole的$request->server中取。
简单实现
server.php
on("start", function ($server) { echo "Swoole http server is started at http://0.0.0.0:8888\n";});$http->on("request", function ($request, $response) { // Instantiate the app $config = [ 'settings' => [ 'addContentLengthHeader' => false, ] ]; $config['environment'] = function () use($request) { $server = []; foreach ($request->server as $key => $value) { $server[strtoupper($key)] = $value; } return new Environment($server); }; $app = new \Slim\App($config); // Register routes require APP . '/routes.php'; // Run app $slimResponse = $app->run(true); $headers = $slimResponse->getHeaders(); foreach ($headers as $name => $values) { $response->header($name, implode(", ", $values)); } $response->header("X-Powered-By", "Salamander"); $response->end($slimResponse->getBody());});$http->start(); 注意$request->server中key都是小写的，所以这里转化了一下。
routes.php（在App目录中）
get('/', function (Request $request, Response $response) { $response->getBody()->write('Hello Salamander'); return $response;});$app->get('/user/{uid}', function (Request $request, Response $response, $args) { $response->getBody()->write('Hello User:' . $args['uid']); return $response;}); 测试
访问/
访问/user/45
打包下载测试
tip：环境基于docker的，运行docker-compose up即可