基于ElementUI封装组件库（二）

这章继续解析ElementUI的css打包方式

elementUI组件的css文件单独维护在/packages/theme-chalk/src中，每个单独的组件对应一个scss
先看package.json

  "scripts": {
    "bootstrap": "yarn || npm i",
    "build:file": "node build/bin/iconInit.js & node build/bin/build-entry.js & node build/bin/i18n.js & node build/bin/version.js",
    "build:theme": "node build/bin/gen-cssfile && gulp build --gulpfile packages/theme-chalk/gulpfile.js && cp-cli packages/theme-chalk/lib lib/theme-chalk",
    "build:utils": "cross-env BABEL_ENV=utils babel src --out-dir lib --ignore src/index.js",
    "build:umd": "node build/bin/build-locale.js",
    "clean": "rimraf lib && rimraf packages/*/lib && rimraf test/**/coverage",
    "deploy:build": "npm run build:file && cross-env NODE_ENV=production webpack --config build/webpack.demo.js && echo element.eleme.io>>examples/element-ui/CNAME",
    "deploy:extension": "cross-env NODE_ENV=production webpack --config build/webpack.extension.js",
    "dev:extension": "rimraf examples/extension/dist && cross-env NODE_ENV=development webpack --watch --config build/webpack.extension.js",
    "dev:umd": "webpack --config build/webpack.conf.js",
    "dev": "npm run bootstrap && npm run build:file && cross-env NODE_ENV=development webpack-dev-server --config build/webpack.demo.js & node build/bin/template.js",
    "dev:play": "npm run build:file && cross-env NODE_ENV=development PLAY_ENV=true webpack-dev-server --config build/webpack.demo.js",
    "dist": "npm run clean && npm run build:file && npm run lint && webpack --config build/webpack.conf.js && webpack --config build/webpack.common.js && webpack --config build/webpack.component.js && npm run build:utils && npm run build:umd && npm run build:theme",
    "i18n": "node build/bin/i18n.js",
    "lint": "eslint src/**/* test/**/* packages/**/* build/**/* --quiet",
    "pub": "npm run bootstrap && sh build/git-release.sh && sh build/release.sh && node build/bin/gen-indices.js",
    "test": "npm run lint && npm run build:theme && cross-env CI_ENV=/dev/ BABEL_ENV=test karma start test/unit/karma.conf.js --single-run",
    "test:watch": "npm run build:theme && cross-env BABEL_ENV=test karma start test/unit/karma.conf.js"
  },

build:theme 打包组件的scss文件

"node build/bin/gen-cssfile && gulp build --gulpfile packages/theme-chalk/gulpfile.js && cp-cli packages/theme-chalk/lib lib/theme-chalk"

node build/bin/gen-cssfile 创建每个组件的scss文件及index.scss文件

gulp build --gulpfile packages/theme-chalk/gulpfile.js 将组件的/packages/theme-chalk/src/**.scss  解析压缩到./lib中，可以单独运行一下看看效果

'use strict';

const { series, src, dest } = require('gulp');
const sass = require('gulp-sass');
const autoprefixer = require('gulp-autoprefixer');
const cssmin = require('gulp-cssmin');

function compile() {
  return src('./src/*.scss')
    .pipe(sass.sync())
    .pipe(autoprefixer({
      browsers: ['ie > 9', 'last 2 versions'],
      cascade: false
    }))
    .pipe(cssmin())
    .pipe(dest('./lib'));
}

function copyfont() {
  return src('./src/fonts/**')
    .pipe(cssmin())
    .pipe(dest('./lib/fonts'));
}

exports.build = series(compile, copyfont);

cp-cli packages/theme-chalk/lib lib/theme-chalk 将packages/theme-chalk/lib文件copy到lib/theme-chalk

lib目录如下

 注：

1.为什么全量引入时还需要引入css文件，而按需引入不需要
element组件样式是分离的，build出来的包只包含模版和js代码，没有css文件

按需引入时，需安装babel-plugin-component，配置.babelrc 文件

{
  "presets": [["es2015", { "modules": false }]],
  "plugins": [
    [
      "component",
      {
        "libraryName": "element-ui",
        "styleLibraryName": "theme-chalk"
      }
    ]
  ]
}

import { Button } from 'components' =>

 var button = require('components/lib/button')

require('components/lib/theme-chalk/button.css')

2.引申：package.json 中files: {} 为npm publish中的ignore配置

"files": [
  "lib",
  "src",
  "packages",
  "types"
]