This plugin can extract theme color styles from all the outputed css files (such as element-ui theme colors), and make a 'theme-colors.css' file which only contains color styles. At runtime in your web page, the client part will help you to download this css file, and then replace the colors into new customized colors dynamicly.

This is a sample: https://hzsrc-vue-webpack4-elementui.netlify.com/themeColor.html

Implementation (Chinese): https://segmentfault.com/a/1190000016061608

Install

npm i -D webpack-theme-color-replacer

Cofig for webpack

const ThemeColorReplacer = require('webpack-theme-color-replacer')

module.exports = {
    // ..... other config
    plugins: [
        new ThemeColorReplacer({
            matchColors: ['#ed4040', '#4b0', '255,80,80', '27, 92.531%, 52.745%'], // colors array for extracting css file, support rgb and hsl.
            fileName: 'css/theme-colors-[contenthash:8].css', //optional. output css file name, suport [contenthash] and [hash].
            // resolveCss(resultCss) { // optional. Resolve result css code as you wish.
            //     return resultCss.replace(/#ccc/g, '#eee')
            // },
            externalCssFiles: ['./node_modules/element-ui/lib/theme-chalk/index.css'], // optional, String or string array. Set external css files (such as cdn css) to extract colors.
            // changeSelector(selector, util) { // optional, Funciton. Changing css selectors, in order to raise css priority, to resolve lazy-loading problems.
            //     return util.changeEach(selector, '.el-button--default')
            // },
            injectCss: false, // optional. Inject css text into js file, no need to download `theme-colors-xxx.css` any more.
            isJsUgly: process.env.NODE_ENV !== 'development', // optional. Set to `true` if your js is uglified. Default is set by process.env.NODE_ENV.
        })
    ],
}

If you use customized runtime-chunk filename, it should contains a string manifest., like this:

optimization: {
  runtimeChunk: {
    name: entrypoint => 'manifest.' +  entrypoint.name,
  },
}

You can view this sample: https://github.com/hzsrc/vue-element-ui-scaffold-webpack4/blob/master/build/webpack.base.conf.js

Other build tool(not webpack)

Otherwise, if you use other build tool(like gulp) but not webpack, you can use this plugin by nodejs:

var nodeRun = require('webpack-theme-color-replacer/src/nodeRun');
var {code, outFile} = nodeRun({
    src: 'src/css/**/*.css', // source css files. string or string array, as `glob`.
    matchColors: ['#ed4040', '#4b0', '255,80,80', '27, 92.531%, 52.745%'],
    fileName: 'css/theme-colors-[contenthash:8].css',
    // ...
})
// do sth with outFile

See this sample: https://github.com/hzsrc/webpack-theme-color-replacer/blob/master/src/nodeRun.js

Usage in your runtime web page

Like this:

import client from 'webpack-theme-color-replacer/client'

// change theme colors at runtime.
export function changeColor() {
  var options = {
    newColors: ['#f67a17', '#f67a17', '160,20,255', '285,78.182%,56.863%'], // new colors array, one-to-one corresponde with `matchColors`
    // appendToEl: 'head', //optional. The element selector for appending child with `<style>`, default is 'body'. Using `appendToEl: 'body'` can make the css priority higher than any css in <head>
    // changeUrl(cssUrl) {
    //   return `/${cssUrl}`; // while router is not `hash` mode, it needs absolute path
    // },
  }

  client.changer.changeColor(options, Promise).then(() => {
      console.log('Theme colors changed!')
  })
}

You can view this sample: https://github.com/hzsrc/vue-element-ui-scaffold-webpack4/blob/master/src/js/themeColorClient.js

Options for build

These options are used for new ThemeColorReplacer(options).

* matchColors: Array<string>

Colors array for extracting css file. Css rules which have any one of these colors will be extracted out.

* fileName: string

Optional. output css file name, suport [contenthash] and [hash].

* resolveCss: Function(resultCss : string) : string

Optional. Resolve result css code as you wish.

* externalCssFiles : string | Array<string>

Optional. Set external css files (such as cdn css) to extract colors.

* changeSelector : Function(selector: string, util: { rules: Array<String>, changeEach: Function } ): string

Optional. Changing css selectors, in order to raise css priority, to resolve lazy-loading problems.

* injectCss: boolean

Optional. Inject css text into js file, no need to download theme-colors-xxx.css any more.

* isJsUgly: boolean

Optional. Default value: process.env.NODE_ENV !== 'development'. Set to true if your js is uglified. Default is set by process.env.NODE_ENV.

Options for runtime

These options are used for client.changer.changeColor(options)

* newColors: Array<string>

New colors array for changing, one-to-one corresponde with matchColors.

* appendToEl: string

Optional. The element selector for this plugin to appending with child node <style>. Default is 'body'. Using appendToEl: 'body' can make the priority of theme-color-css higher than any other css in element.

* changeUrl: Function(cssUrl: string): string

Optional. Change the theme-color-css download url if you need. While router is not hash mode, it needs to change url to an absolute path(start with /).

issues report

If you have issues with this plugin, please run your command with --theme_debug option, such as npm run dev --theme_debug, then upload the outputed _tmp_xxx files while reporting issues. Thanks!

update log

1.3.2

Default to append <style>...</style> to <body>, not to <head> any more, in order to resolve most priority problems in lazy loading pages. Thanks to iota9star : 15

hellolibo/webpack-theme-color-replacer