Justin's Words

Express 基础

Posted on | In |

创建 package.json

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{
    "name": "express-basis",
    "main": "service.js",
    "dependencies": {
    "body-parser": "^1.13.3",
    "express": "^4.13.3",
    "jade": "^1.11.0",
    "mongoose": "^4.1.4",
    "morgan": "^1.6.1",
    "underscore": "^1.8.3"
    }
}
  • body-parser 是为了取得 req.body.param。
  • express 是框架。
  • jade 是渲染引擎。
  • mongoose 操作 MongoDB。
  • morgan 输出访问信息。
  • underscore 是神器。

着手 service.js

npm install 之后，开始写 server.js。

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var express = require('express');
var bodyParser = require('body-parser');
var app = express();
var morgan = require('morgan');
var path = require('path');
var jade = require('jade');
var _ = require('underscore');

##### 使用 _morgan_ 输出访问信息

app.use(morgan('dev')); // log requests to the console

##### 配置 _body-parser_

app.use(bodyParser.urlencoded({extended: true}));
app.use(bodyParser.json());

设置端口

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var port = process.env.PORT || 2100;

连接数据库

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var mongoose = require('mongoose');
mongoose.connect('mongodb://127.0.0.1:27017/rest'); // connect to our database

添加 middleware 通过 router.use

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var router = express.Router();

// middleware to use for all requests
router.use(function (req, res, next) {
    // do logging
    console.log('Something is happening.');
    next();
});

测试路由

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router.get('/', function (req, res) {
    res.json({message: 'hooray! welcome to our api!'});
});

添加一个 app/models/bear.js

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var mongoose     = require('mongoose');
var Schema       = mongoose.Schema;

var BearSchema   = new Schema({
    name: String
});

module.exports = mongoose.model('Bear', BearSchema);

往 MongoDB 添加数据和获取数据

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var Bear = require('./app/models/bear');

router.route('/bears')
    .post(function (req, res) {

        var bear = new Bear();      // create a new instance of the Bear model
        bear.name = req.body.name;  // set the bears name (comes from the request)

        bear.save(function (err) {
            if (err)
                res.send(err);

            res.json({message: 'Bear created!'});
        });

    })
    .get(function (req, res) {
        Bear.find(function (err, bears) {
            if (err)
                res.send(err);

            res.json(bears);
        });
    });

添加数据库搜索、更新和删除功能

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router.route('/bears/:bear_id')

    // get the bear with that id
    .get(function (req, res) {
        Bear.findById(req.params.bear_id, function (err, bear) {
            if (err)
                res.send(err);
            res.json(bear);
        });
    })

    // update the bear with this id
    .put(function (req, res) {
        Bear.findById(req.params.bear_id, function (err, bear) {

            if (err)
                res.send(err);

            bear.name = req.body.name;
            bear.save(function (err) {
                if (err)
                    res.send(err);

                res.json({message: 'Bear updated!'});
            });

        });
    })
    // delete the bear with this id
    .delete(function (req, res) {
        Bear.remove({
            _id: req.params.bear_id
        }, function (err, bear) {
            if (err)
                res.send(err);

            res.json({message: 'Successfully deleted'});
        });
    });

注册路由

意味着上述 router 操作都是在 /api 下完成的

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app.use('/api', router);

设置模板路径、模板渲染引擎和渲染配置

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app.set('views', path.join(__dirname + '/views'));
app.set('view engine', 'jade');
// 默认为 development，编译代码为 pretty
app.locals.pretty = app.get('env') != 'production';

设置静态文件路径

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app.use('/static', express.static('public'));

设置页面数据和渲染文件

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app.get('/', function (req, res) {
    var data = {
        title: 'Express',
        message: 'Hello earth!'
    };
    res.render('index', data);
});

不适用引擎渲染时则使用 res.sendFile

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res.sendFile(path.join(__dirname + '/view/index'));

监听端口

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app.listen(port);

Jade 模板

views/index.jade

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doctype html
html(lang='en-US')
    head
    meta(charset='utf-8')
    link(rel='stylesheet', href='static/css/bootstrap.min.css')
    title #{title}
    body
    .container
        header.jumbotron
        h1 #{message}

    include common-js

common-js.jade

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script(type='text/javascript', src='static/js/jquery.js')
script(type='text/javascript', src='static/js/bootstrap.min.js')

延伸阅读：Build a RESTful API Using Node and Express 4