Sails.js 起航 - 后端框架选秀

[ufologist]

Sails.js 请先做个自我介绍吧

Sails is a lightweight framework that sits on top of Express.

• Sails.js

  The web framework of your dreams

• ThinkJS

  The Web framework beyond your dreams

对比下 ThinkJS, 可以看到 Sails 的功能更为强大, 当然也就会更加地复杂...

新建一个项目跑起来

具体文档请参考官方的 Getting Started, 新建项目成功后访问 http://localhost:1337/ 来查看效果, 以下示例基于 sails@0.12.11 版本

npm install sails -g

sails new test-sails
cd test-sails
sails lift

由于 Sails 没有自带 autorealod 功能, 开发阶段你修改代码后必须每次重启 sails lift, 这样实在是太麻烦了, 因此推荐开发阶段推荐使用 nodemon 执行 nodemon app.js 来自动重启, 另外 sails console 是一个非常实用的命令行工具.

官方提供的文档只是做了分类, 没有向导似的文档, 让你可以一步接一步从入门到进阶, 因此文档看起来会让人觉得混乱费劲, 建议先从 Controllers 看起.

• Anatomy 项目目录文件详解
• Concepts 各种内置功能详解
• Reference 相当于 API 文档

Controllers

Controllers (the C in MVC) are the principal objects in your Sails application that are responsible for responding to requests from a web browser, mobile application or any other system capable of communicating with a server. They often act as a middleman between your models and views. For many applications, the controllers will contain the bulk of your project’s business logic.

Controllers are comprised of a set of methods called actions. Actions are bound to routes in your application, so that when a client requests the route, the action is executed to perform some business logic and send a response.

完整的 controller 示例

列举了一般开发中所需要的功能

// api/controllers/HelloController.js
// sails generate controller hello index foo bar
//
// blueprint action route 机制会自动创建路由来连接 controller 的方法
// http://sailsjs.com/documentation/concepts/controllers/routing-to-controllers
// http://sailsjs.org/documentation/reference/blueprint-api
//
// 因此对应的路由规则为 /:controllerIdentity/:nameOfAction
// 这里 hello 即为 controller 的 Identity, nameOfAction 即各个方法名
module.exports = {
    // 默认的 action
    // http://sailsjs.com/documentation/reference/configuration/sails-config-blueprints
    // actions: true
    // Whether routes are automatically generated for every action
    // in your controllers (also maps index to /:controller) '/:controller',
    // '/:controller/index', and '/:controller/:action'
    //
    // http://localhost:1337/hello
    index: function(req, res) {
        // 获取 URL
        console.log('url', req.method, req.host, req.url, sails.getBaseUrl());

        // 获取请求参数
        // pathparam 必须在 config/routes.js 中配置 URL Slugs 路由
        // http://sailsjs.com/documentation/concepts/routes/url-slugs
        console.log('pathparam-a', req.params['a']);
        console.log('pathparam-b', req.params['b']);
        console.log('urlparam-c', req.query['c']);
        console.log('GET param', req.query);
        console.log('POST param', req.body);
        console.log('param', req.allParams());

        // 更多的 req res 方法
        // http://sailsjs.com/documentation/reference/request-req
        // http://sailsjs.com/documentation/reference/response-res
        return res.send('index');
    },
    // http://localhost:1337/hello/file
    file: function(req, res) {
        console.log('POST param', req.body);
        // http://sailsjs.com/documentation/concepts/file-uploads
        req.file('fileField').upload(function(err, uploadedFiles) {
            return res.send({
                body: req.body, // 包含 form 表单中除开 file 类型的其他字段的值
                files: uploadedFiles
            });
        });
    },
    // http://localhost:1337/hello/foo
    foo: function(req, res) {
        // 对应 api/responses 中的文件名
        return res.ok({foo: 'bar'});
        // 返回 JSON/JSONP
        // return res.json({a: 1});
        // return res.jsonp({a: 1}); // http://localhost:1337/hello/foo?callback=abc
        // 跳转页面
        // return res.redirect('http://sailsjs.com');
    },
    // http://localhost:1337/hello/global
    global: function(req, res) {
        // [Globals](http://sailsjs.com/documentation/concepts/globals)
        console.log('Globals: The App Object (sails)', sails.config.environment);
        sails.log.info('Globals: Models', Hello.find);
        sails.log.info('Globals: Services', Baz.find);
        return res.send(sails.config.environment);
    },
    // http://localhost:1337/hello/model
    model: function(req, res) {
        // 首先需要配置 api/models/Hello.js 的 attributes 属性来映射数据库字段
        // 否则只会查询出一个 id 字段(必须数据库表也有这个字段)
        // module.exports = {
        //     tableName: 'hello1', // 自定义表名
        //     attributes: {
        //         name: {},
        //         abc: {
        //             columnName: 'name1'
        //         },
        //         name2: {}
        //     }
        // };
        // 通过 Globals 方式来使用 Model
        Hello.find({
            // id: 1
        }).then(function(data) {
            res.ok(data);
        });

        // 指定 SQL 语句执行查询
        Hello.query('select * from hello where id = ?', [2], function(err, rawResult) {
            console.log('sql', rawResult);
        });
    },
    // http://localhost:1337/hello/view
    view: function(req, res) {
        // 变量赋值和模版渲染
        // 默认渲染 views/hello/view.ejs
        return res.view({
            title: '我们一起来学习 Sails',
            author: 'Sun'
        });
    }
};

重点内容

• api
  • controllers
  • models
  • policies
  • responses
  • services
• config
  • routes.js
  • views.js
  • models.js
  • policies.js
  • blueprints.js
  • log.js
• app.js Deployment

听听吐槽

• Don’t Use Sails (or Waterline)

其他选择

• Express

  • Express application generator

  提供了很好的路由模块化组织方式, 具体代码可以参考 expressjs/generator

  // routes/index.js
  var express = require('express');
  var router = express.Router();
  router.get('/', function(req, res, next) {
      res.send('index');
  });
  module.exports = router;
  -----------------------
  // routes/users.js
  var express = require('express');
  var router = express.Router();
  router.get('/', function(req, res, next) {
      res.send('user index');
  });
  module.exports = router;
  -----------------------
  // app.js
  app.use('/', require('./routes/index'));
  app.use('/users', require('./routes/users'));

  • Express Middleware

• Koa

  • 路由中间件

  Koa 没有自带路由中间件, 可以使用 koajs/route 这个简单的实现, 不过一般推荐使用 koa-router 功能更全.

  // routes/index.js
  var Router = require('koa-router');
  var router = new Router();
  router.get('/', function *() {
      this.body = 'index';
  });
  module.exports = router;
  -----------------------
  // routes/users.js
  var Router = require('koa-router');
  var router = new Router();
  router.get('/', function *() {
      this.body = 'user index';
  });
  module.exports = router;
  -----------------------
  // app.js
  app.use(require('./routes/index.js').prefix('/').routes());
  app.use(require('./routes/users.js').prefix('/users').routes());

  • Joi Object schema description language and validator for JavaScript objects.
  • Boom HTTP-friendly error objects
• Node.js Frameworks
  • MVC
  • Sinatra-like
  • Rails-like
  • Full-stack
  • REST API

[px0078]

现在express的教程比较多... koa的 function *(){} 和yield都不熟悉

[ufologist]

@px0078 Express 确实是最流行的, 生态资源相当丰富, 如果是第一次接触后端开发, 可以试一试. Koa 的话算是另一种尝试了, 功能比较单一, 虽然是 Express 团队做出来的, 但生态圈还是差了一大截, 总体来说还不如直接上 ThinkJS

[px0078]

为了前后端分离和SEO，在尝试前端同构，尤雨溪的示例就是express的，所以打算照着他的改 https://github.com/vuejs/vue-hackernews-2.0