multiple-themes-webpack-plugin

A webpack plugin to generate multiple themes for your app.

Wraps webpack-css-themes-plugin.

Installation

Install from NPM:

npm install -D multiple-themes-webpack-plugin

Also install html-webpack-plugin if you don't have it already:

npm install -D html-webpack-plugin

Usage

Setting up the plugin

In your webpack.config.js:

import MultipleThemesPlugin from 'multiple-themes-webpack-plugin/dist/MultipleThemesPlugin';

Add it to your plugins list:

{
    plugins: {
        // ... your other plugins,
        new MultipleThemesPlugin({
            themes: {
                // for each theme, assign a name and a path to its variables
                dark: path.resolve(__dirname, './src/themes/theme-dark.less'),
                light: path.resolve(__dirname, './src/themes/theme-light.less'),
            },
        }),
        // Don't forget to include the html-webpack-plugin plugin
        new HtmlWebpackPlugin({
            template: path.resolve(__dirname, './index.html'),
        }),
    }
}

Switching themes at runtime

import the switch function anywhere in your project:

import {switchTheme} from 'multiple-themes-webpack-plugin';

Call that function with the new theme's name as an argument:

switchTheme('dark');

Developer recommendation: If you use Typescript, It is recommended to use enums for theme names - for convenience, autocomplete options, and to make sure you won't have typos.

Gotcha's

Default theme

To have a default theme preloaded directly in the HTML file (mainly to prevent a FOUC), Add this before your closing </head> tag:

    <%= htmlWebpackPlugin.options.extraHeadTags %>

And in the plugin options:

new MultipleThemesPlugin({
    themes: {
        dark: path.resolve(__dirname, './src/themes/theme-dark.less'),
        light: path.resolve(__dirname, './src/themes/theme-light.less'),
    },
    defaultTheme: 'dark',
}),

CSS Imports inside .less files

If you try to @import a .css file inside a .less file, You'll get the following error:

Error: Didn't get a result from child compiler

To avoid this, tell the compiler to treat the file as a Less file using the Import Options feature:

@import (less) './assets/fonts/Lato/Lato.css';

See webpack-css-themes-plugin#4 for more information.

Webpack config entry

Due to a bug in the base plugin, the entry option in webpack.config.js must be an object. If it's not an object already in your config, the simplest solution is to wrap your current entry with a single-key object:

{
    // from:
    entry: ['react-hot-loader/patch', './src/index.tsx'],

    // to:
    entry: {
        app: ['react-hot-loader/patch', './src/index.tsx'],
    },
}

Exclude Assets Plugin

Default generated CSS Assets are excluded from the html file, since this plugin appends its own styles automatically. If you ever wonder why you don't see your compiled themes without supplying a default theme, this is the reason.