Express.js Tutorial: Build RESTful APIs with Node and Express

Express.js Tutorial: Build RESTful APIs with Node and Express | Mosh

在Youtube上看到Mosh的一篇关于使用Node和Express构建RESTful APIs的示例，对应的视频地址是：Express.js Tutorial: Build RESTful APIs with Node and Express | Mosh，作者Mosh的Youtube地址是：Programming with Mosh

TABLE OF CONTENT:

00:49 What are RESTful APIs
06:48 Introducing Express
09:09 Your First Web Server
14:57 Nodemon
16:29 Environment Variables
19:44 Route Parameters
25:22 Handling HTTP GET Requests
30:09 Handling HTTP POST Requests
33:53 Calling APIs using Postman
36:03 Input Validation
44:03 Handling HTTP PUT Requests
52:33 Handling HTTP DELETE Requests

http://programmingwithmosh.com

创建程序

首先保证在自己的系统下安装了Node.js程序，然后安装配置node和npm、cnpm等
然后使用cnpm或npm安装express和joi依赖，

cnpm install express joi

对应的代码如下：

const Joi = require('joi');
const express = require('express');
const app = express();

app.use(express.json());

// 课程列表数组
const courses =[
  { id: 1, name: '语文' },
  { id: 2, name: '数学' },
  { id: 3, name: '英语' },
  { id: 4, name: '计算机组成原理' },
  { id: 5, name: '数据结构' },
  { id: 6, name: '操作系统' },
  { id: 7, name: '编译原理' }
]

app.get('/', (req, res) => {
  res.send('Hello World');
})

// 获取所有的课程信息
app.get('/api/courses', (req, res) => {
  res.send(courses);
});

// 提交一门课程
app.post('/api/courses', (req, res) => {
  const { error } = validateCourse(req.body); // result.error
  if (error) {
    return res.status(400).send(error.details[0].message);
  }

  // 在提交课程前，对课程名进行校验，若课程名为空或者小于3个字符，则返回
  // if (!req.body.name || req.body.name.length < 3) {
  //   // 400 Bad Request
  //   res.status(400).send('Name is required and should be minimum 3 characters.');
  //   return;
  // }

  // 创建一个课程对象
  const course = {
    id: courses.length + 1,
    name: req.body.name
  };
  // 向课程列表数组中添加一个新项
  courses.push(course);
  res.send(course);
});

// 根据课程id查询某个课程
app.get('/api/courses/:id', (req, res) => {
  const course = courses.find(c => c.id === parseInt(req.params.id));
  if (!course) { // 404
    return res.status(404).send('The course with the given ID was not found!');
  }
  res.send(course);
});

// 根据课程id更新某门课程
app.put('/api/courses/:id', (req, res) => {
  // Look up the course
  // If not existing, return 404
  const course = courses.find(c => c.id === parseInt(req.params.id));
  if (!course) { // 404
    return res.status(404).send('The course with the given ID was not found!');
  }
  // Validate
  // If invalid, return 400 - Bad request
  const { error } = validateCourse(req.body); // result.error
  if (error) {
    return res.status(400).send(error.details[0].message);
  }
  // Update course
  // Return the updated course
  course.name = req.body.name;
  res.send(course);
});

// 根据课程id删除某门课程
app.delete('/api/courses/:id', (req, res) => {
  // Look up the course
  // Not existing, return 404
  const course = courses.find(c => c.id === parseInt(req.params.id));
  if (!course) { // 404
    return res.status(404).send('The course with the given ID was not found!');
  }

  // Delete
  const index = courses.indexOf(course);
  courses.splice(index, 1);

  // Return the same course
  res.send(course);
})

// app.get('/api/posts/:year/:month', (req, res) => {
//   res.send(req.params);
//   //res.send(req.query);
// });

// app.post()
// app.put()
// app.delete()
const port = process.env.PORT || 3000;
app.listen(port, () => {
  console.log(`App Listening on port ${port}...`);
});

function validateCourse(course) {
  const schema = {
    name: Joi.string().min(3).required()
  };

  return Joi.validate(course, schema);
}

关于http接口测试工具，可以使用Postman或者在VSCode中使用rest-client插件进行测试，或者使用curl工具进行测试。

不过需要注意的是，在npm官网上作者说joi包已经被废弃了，建议使用@hapi/joi

This package has been deprecated
Author message:

This module has moved and is now available at @hapi/joi. Please update your dependencies as this version is no longer maintained an may contain bugs and security issues.