Express搭建在线便利贴——Webpack配置

使用express应用生成器搭建项目

1. 使用一下命令安装生成器

   $ npm install express-generator -g

2. 使用-h 查看命令选项

   $ express -h
   
     Usage: express [options][dir]
   
     Options:
   
       -h, --help          output usage information
           --version       output the version number
       -e, --ejs           add ejs engine support
           --hbs           add handlebars engine support
           --pug           add pug engine support
       -H, --hogan         add hogan.js engine support
       -v, --view <engine> add view <engine> support (ejs|hbs|hjs|jade|pug|twig|            vash) (defaults to jade)
       -c, --css <engine>  add stylesheet <engine> support (less|stylus|compass|            sass) (defaults to plain css)
           --git           add .gitignore
       -f, --force         force on non-empty directory

3. 创建名为node-sticky的express应用程序

   $ express --pug --css=less node-sticky//我默认安装了less和pug模板引擎

4. 安装依赖

   $ cd node-sticky
   $ npm install

5. 启动应用程序

   $ npm start
   
   > node-sticky@0.0.0 start /node-sticky
   > node ./bin/www

6. 在浏览器输入localhost:3000 就可以看到欢迎画面了。

7. 目前的目录结构

       ├── app.js
   ├── bin
   │   └── www
   ├── package.json
   ├── public
   │   ├── images
   │   ├── javascripts
   │   └── stylesheets
   │       └── style.css
   ├── routes
   │   ├── index.js
   │   └── users.js
   └── views
       ├── error.pug
       ├── index.pug
       └── layout.pug

添加src目录，配置相应的webpack

1. 我们把前端的源码放在src目录下，使用webpack打包到node的public目录下面。添加之后的目录结构为：

   ├── app.js
   ├── bin
   |  └── www
   ├── package-lock.json
   ├── package.json
   ├── public
   |  ├── images
   |  ├── javascripts
   |  └── stylesheets
   |     └── style.less
   ├── routes
   |  ├── index.js
   |  └── users.js
   ├── src                          //前端源码目录
   |  ├── js
   |  |  ├── app                    //webpack入口目录
   |  |  |  └── index.js
   |  |  ├── lib                        //一些工具目录
   |  |  |—— module             //js模块
   |  ├── less                            //less目录
   |  └── webpack.config.js    //webpack配置文件
   └── views
      ├── error.pug
      ├── index.pug
      └── layout.pug

   我使用的mac的tree命令生成目录树，具体命令：tree -l 4 --ignore=node_modules，把依赖目录忽略。

2. 配置webpack

   1. 配置之前需要先安装一下webpack依赖

      $ npm install webpack --save-dev

   2. 然后简单配置webpack入口文件和出口文件。

      let webpack = require('webpack')
      let path = require('path')
      
      module.exports = {
          entry: path.join(__dirname,'/js/app/index.js'),
          output: {
              path: path.join(__dirname,'../public'),
              filename: 'js/index.js'
          }
      }

   3. 在终端运行webpack

      $ cd src
      $ webpack
      

Version: webpack 4.3.0
Time: 265ms
Built at: 2018-3-29 05:21:58
      Asset       Size  Chunks             Chunk Names
js/index.js  676 bytes       0  [emitted]  main
Entrypoint main = js/index.js
   [0] ./js/module/b.js 36 bytes {0} [built]
   [1] ./js/module/a.js 36 bytes {0} [built]
   [2] ./js/app/index.js 65 bytes {0} [built]

    WARNING in configuration
    The 'mode' option has not been set. Set 'mode' option to 'development' or 'production' to enable defaults for this environment.
    ~~~
4. 最后给一个警告，要加上webpack运行的环境，在后面加上就好了

    ~~~
    $ webpack --mode development
    ~~~
    

配置package.json的script脚本

1. 但是我们不能一直在src里面执行，我们要在根目录下执行，所有要使用package.json里面的srcipt字段脚本命令。需要配置webpack的--config指定脚本文件。

   //package.json
   {
     "name": "node-sticky",
     "version": "0.0.0",
     "private": true,
     "scripts": {
       "start": "node ./bin/www",
       "webpack": "webpack --config=src/webpack.config.js --mode=development"
     },
     "dependencies": {
       "cookie-parser": "~1.4.3",
       "debug": "~2.6.9",
       "express": "~4.16.0",
       "http-errors": "~1.6.2",
       "less-middleware": "~2.2.1",
       "morgan": "~1.9.0",
       "pug": "2.0.0-beta11",
       "webpack": "^4.3.0"
     }
   }

2. 然后进入个目录执行npm run webpack就会发现报错了。

   $ cd ..
   $ npm run webpack                                                                                                            
   
   > node-sticky@0.0.0 webpack /Users/lanbo/projects/node-sticky
   > webpack --config=src/webpack.config.js
   
   The CLI moved into a separate package: webpack-cli.
   Please install 'webpack-cli' in addition to webpack itself to use the CLI.
   -> When using npm: npm install webpack-cli -D
   -> When using yarn: yarn add webpack-cli -D
   npm ERR! code ELIFECYCLE
   npm ERR! errno 1
   npm ERR! node-sticky@0.0.0 webpack: `webpack --config=src/webpack.config.js`
   npm ERR! Exit status 1
   npm ERR!
   npm ERR! Failed at the node-sticky@0.0.0 webpack script.
   npm ERR! This is probably not a problem with npm. There is likely additional                 logging output above.
   
   npm ERR! A complete log of this run can be found in:
   npm ERR!     /Users/lanbo/.npm/_logs/2018-03-28T21_33_04_687Z-debug.log

3. 根据报错内容需要安装webpack-cli，那就照着做吧。

   $ npm install webpack-cli --save-dev

4. 然后再次执行，就发现成功啦，哈哈哈~~然后问题来了，不能每次都要自己手动去webpack，有一个工具能自动去打包就好了，正好有这个工具--onchange.

   $ npm install onchange --save-dev

5. 配置script脚本

   $ "watch": "onchange 'src/**/*.js' 'src/**/*.less' -- npm run webpack"

6. 在另外开一个终端，启动脚本就不去管他了，js和less文件有变动会自动去打包。

   $ npm run watch

一点点记录，一步步成长，加油~~~~