• Multiple themes supported via custom variables.
• Generating themes via webpack.
• Themes switch without page reload.
• Supported formats: css, less, postcss, sass.

npm install themes-switch --save

const ThemesGeneratorPlugin = require('themes-switch/ThemesGeneratorPlugin');

module.exports = {
  entry: {
    main: './src/main.js'
  },
  output: {
    filename: '[name]-[hash].js',
    chunkFilename: '[name]-[hash].js',
    path: `${__dirname}/build`,
    publicPath: ''
  },
  module: {
    rules: [
      // ...
    ]
  },
  plugins: [
    new ThemesGeneratorPlugin({
      srcDir: 'src',
      themesDir: 'src/assets/themes',
      outputDir: 'static/css',
      defaultStyleName: 'default.less',
      themesLoader: {
        test: /\.(less|css)$/,
        loaders: [
          { loader: require.resolve('css-loader') },
          { loader: require.resolve('less-loader') }
        ]
      }
    })
  ]
};

• Create directory for themes, and set it to option themesDir:

src
  - themes
    - dark.less
    - default.less
    - light.less

• Import your default theme into default.less:

@import 'light.less';

• Specify theme variables:

@color-main: #222A42;
@color-text: #FFF;

When you use sass, you should add default flag to default theme variables, such as $color-main: #0A6EFA !default;.

• Import default.less when you use theme variables:

@import 'default.less';

.main {
  background: @color-main;
}

• ThemesGeneratorPlugin scans files in themesDir and files that import default.less, then generates separated files for all themes automatically.

• You can access the themes info via process.themes in your code, value such as { 'theme-dark': 'css/dark.css', 'theme-light': 'css/light.css' }.

• Call changeTheme method to switch to new theme by pass theme name and url.

• theme: new theme name, such as theme-dark.
• themeUrl: new theme url, such as css/dark.css. You can get the value from process.themes
• currentLink: current link element that would be removed when new element had been loaded.
• onLoad: callback when new link was loaded.

• link: link element that would be removed.

It will delete temp directory. You can call the method as needed, e.g. when you stop webpack-dev-server in development mode.