webpack插件 - css主题颜色提取-主题切换

css-color-extract-plugin

---

Install

npm install css-color-extract-plugin

yarn add css-color-extract-plugin

• 该插件主要用于提取主题颜色
• 提取到的css数据会挂载到window下
• 通过颜色替换再插入到<style>，可达到动态修改主题的目的

---

Usage

---

// webpack.config.js

const CssColorExtractPlugin = require('css-color-extract-plugin').default;
const PRIMARY_COLOR = '#1890ff';
module.exports = {
    ...
    module: {
        rules: [
          {
            test: /\.css$/,
            exclude: '/\.module\.css$/',
            use: [
                "style-loader", 
                "css-loader", 
                {
                  loader: CssColorExtractPlugin.loader,
                  options: {
                    colors: [ PRIMARY_COLOR ]
                  }
              },
           ]
        },
        {
            test:  /\.module\.css$/,
            use: [
                "style-loader", 
                 {
                   loader: "css-loader", 
                   options: {
                     modules: true,
                     localIdentName: '[path][name]__[local]',
                   }
                                },
                {
                    loader: CssColorExtractPlugin.loader,
                    options: {
                    colors: [ PRIMARY_COLOR ],
                    modules: true,
                    localIdentName: '[path][name]__[local]',
                  }
               },
            ]
        }
      ]
    }
   ...
       plugins: [
      ...
      new CssColorExtractPlugin({ fileName: 'theme' }),
     ]
};

编译后会在html中插入theme.js，其内容类似以下

window.CSS_EXTRACT_COLOR_PLUGIN = [
  {"source":".src-App-module__example {  background: #1890ff;}","fileName":"App.module.scss","matchColors":["#1890ff"]},
  {"source":".src-controller-blog-components-Header-Header-module__theme {  color: #067785;}.src-controller-blog-components-Header-Header-module__pc_header {  background: #1890ff;}.src-controller-blog-components-Header-Header-module__mb_header {  background: #1890ff;}.src-controller-blog-components-Header-Header-module__mb_header .src-controller-blog-components-Header-Header-module__mb_nav {  background: #1890ff;}","fileName":"Header.module.scss","matchColors":["#1890ff"]}
];

接着只要使用简单的正则即可替换主题色

import React, { Component } from 'react';
import styles from './App.module.scss';
import { SketchPicker } from 'react-color';

function replaceColor(source, color, replaceColor) {
    return source.replace(new RegExp(`(:.*?\\s*)(${color})(\\b.*?)(?=})`, 'mig'), (group) => {
        return group.replace(new RegExp(`${color}`, 'mig'), replaceColor);
    });
}

const PRIMARY_COLOR = '#1890ff';

class App extends Component {
    
    async setColor(color) {
        const styleData = window.CSS_EXTRACT_COLOR_PLUGIN || [];
        const cssText = styleData.map((item) => item.source).join('');
        const styleText = replaceColor(cssText, PRIMARY_COLOR, color);
        const style = document.createElement('style');
        style.innerHTML = styleText;
        document.body.appendChild(style);
    }
    render() {
        return (
            <div className={styles['example']}>
                <SketchPicker onChangeComplete={(colorResult) => this.setColor(colorResult.hex)} />
            </div>
        );
    }
}

export default App;

loader Options

 {
    colors: string[]; // 匹配的颜色数组，如果出现颜色层次错误覆盖的情况，需要选上被覆盖的颜色，可通过该选项在不同的文件提取不同的颜色
    only?: boolean = true; // 仅提取选中颜色规则，否则会将整个文件提取进去
    modules?: boolean = false; 
    localIdentName?: string = '';
 }

plugin Options

  {
      fileName?: string; // 提取颜色的文件名,不提供则直接嵌在 script标签中
      variableName?: string = 'CSS_EXTRACT_COLOR_PLUGIN'; // 挂载到window的变量名， 默认 
 CSS_EXTRACT_COLOR_PLUGIN
 }

example

一个更复杂的例子-RyanCMS内容管理系统