关于slim

在php的框架世界中，除了像symfony、laravel以及zend这样的全栈式的框架之外，还存在着一些微框架，比如基于symfony的silex，基于laravel的lumen，以及这篇博客中要讲到的slim框架，他们不像别的框架那样笨重，而且存在很多的配置项，大多数都是开箱即用，学习周期也很短，看看文档大多在半天内就能掌握它的基本用法。

关于restful

RESTful架构：
（1）每一个URI代表一种资源；
（2）客户端和服务器之间，传递这种资源的某种表现层；
（3）客户端通过四个HTTP动词，对服务器端资源进行操作，实现”表现层状态转化”；
（4）GET用来获取资源，POST用来新建资源（也可以用于更新资源），PUT用来更新资源，DELETE用来删除资源。
RESTful误区：
（1）URI包含动词；
（2）URI中加入版本号。
注；以上内容出自阮一峰博文：http://www.ruanyifeng.com/blog/2011/09/restful.html
关于restful只有粗浅的理解，后期读完相关书籍之后再做完善。

slim的安装

这里使用composer安装slim，在命令行下运行如下命令即可安装slim框架：

composer require slim/slim "^3.0"

如果使用的是apache服务器，创建.htaccess文件，内容如下：

RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^ index.php [QSA,L]

再创建index.php文件，内容如下：

<?php
use \Psr\Http\Message\ServerRequestInterface as Request;
use \Psr\Http\Message\ResponseInterface as Response;require 'vendor/autoload.php';$app = new \Slim\App;
$app->get('/', function (Request $request, Response $response) {$response->getBody()->write("Hello, world");return $response;
});
$app->run();

目前的目录结构如下所示：

这时访问http://localhost/slim，即可看到页面上展现出的hello,world。

实战

这里使用这篇文章http://www.codediesel.com/php/create-a-quick-rest-api-using-slim-framework/
中提到的例子来实现一个RESTful API的例子。
创建学生表：

CREATE TABLE IF NOT EXISTS `students` (`student_id` int(10) NOT NULL auto_increment,`score` int(10) default '0',`first_name` varchar(50) default NULL,`last_name` varchar(50) default NULL,PRIMARY KEY  (`student_id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

这里我们手动新增了一条记录：

• 查

相关代码如下：

$app->get('/score/{id}', function (Request $request, Response $response, $args) {try{$db = getDB();$sth = $db->prepare("SELECT * FROM students WHERE student_id = :id");$sth->bindParam(':id', $args['id'], PDO::PARAM_INT);$sth->execute();$student = $sth->fetch(PDO::FETCH_ASSOC);if($student) {$response = $response->withStatus(200)->withHeader('Content-type', 'application/json');$response->getBody()->write(json_encode(['status' => 200,'error' => '','datas' => $student]));} else {$response = $response->withStatus(404)->withHeader('Content-type', 'application/json');$response->getBody()->write(json_encode(['status' => 404,'error' => 'student could not be found','datas' => $student]));}return $response;$db = null;} catch(PDOException $e) {$response = $response->withStatus(500)->withHeader('Content-type', 'application/json');$response->getBody()->write(json_encode(['status' => 500,'error' => $e->getMessage(),'datas' => '']));return $response;$db = null;}
});

获取数据库连接的相关代码如下：

function getDB()
{$dbhost = "localhost";$dbuser = "root";$dbpass = "";$dbname = "test";$mysql_conn_string = "mysql:host=$dbhost;dbname=$dbname";$dbConnection = new PDO($mysql_conn_string, $dbuser, $dbpass);$dbConnection->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);return $dbConnection;
}

此时通过curl访问http://localhost/slim/score/1，得到：

• 改
  相关代码如下：

$app->put('/score/{id}', function(Request $request, Response $response, $args) {try{$putDatas = $request->getParsedBody();$db = getDB();$sth = $db->prepare("UPDATE students SET score = :score WHERE student_id = :id");$sth->bindParam(':score', $putDatas['score'], PDO::PARAM_INT);$sth->bindParam(':id', $args['id'], PDO::PARAM_INT);$ret = $sth->execute();$response = $response->withStatus(200)->withHeader('Content-type', 'application/json');$response->getBody()->write(json_encode(['status' => 200,'error' => '','datas' => 'update successfully']));return $response;$db = null;} catch(PDOException $e) {$response = $response->withStatus(500)->withHeader('Content-type', 'application/json');$response->getBody()->write(json_encode(['status' => 500,'error' => $e->getMessage(),'datas' => '']));return $response;$db = null;}
});

此时通过curl访问http://localhost/slim/score/2，得到：

• 删
  相关代码如下：

$app->delete('/score/{id}', function (Request $request, Response $response, $args) {try{$db = getDB();$sth = $db->prepare("DELETE FROM students WHERE student_id = :id");$sth->bindParam(':id', $args['id'], PDO::PARAM_INT);$sth->execute();$response = $response->withStatus(200)->withHeader('Content-type', 'application/json');$response->getBody()->write(json_encode(['status' => 200,'error' => '','datas' => 'delete successfully']));return $response;$db = null;} catch(PDOException $e) {$response = $response->withStatus(500)->withHeader('Content-type', 'application/json');$response->getBody()->write(json_encode(['status' => 500,'error' => $e->getMessage(),'datas' => '']));return $response;$db = null;}
});

此时通过curl访问http://localhost/slim/score/2，得到：

- 增
相关代码如下：

$app->post('/score', function(Request $request, Response $response, $args) {$postDatas = $request->getParsedBody();try {$db = getDB();$sth = $db->prepare("INSERT INTO students (score, first_name, last_name) VALUES (:score, :firstName, :lastName)");$sth->bindParam(':score', $postDatas['score'], PDO::PARAM_INT);$sth->bindParam(':firstName', $postDatas['firstName'], PDO::PARAM_STR);$sth->bindParam(':lastName', $postDatas['lastName'], PDO::PARAM_STR);$sth->execute();$response = $response->withStatus(200)->withHeader('Content-type', 'application/json');$response->getBody()->write(json_encode(['status' => 200,'error' => '','datas' => 'insert successfully']));return $response;$db = null;} catch(PDOException $e) {$response = $response->withStatus(500)->withHeader('Content-type', 'application/json');$response->getBody()->write(json_encode(['status' => 500,'error' => $e->getMessage(),'datas' => '']));return $response;$db = null;}});

此时通过curl访问http://localhost/slim/score，得到：

注：这篇博文只是做一个入门案例，示例代码有很多坏味道和不规范的地方。