@stencil/postcss

The Stencil PostCSS Plugin

Usage no npm install needed!

<script type="module">
  import stencilPostcss from 'https://cdn.skypack.dev/@stencil/postcss';
</script>

README

@stencil/postcss

This package is used in order to integrate with postcss and all of its plugins.

First, npm install within the project:

npm install @stencil/postcss --save-dev

Next, within the project's stencil.config.ts file, import the plugin and add it to the plugins config. In the example below we're using the autoprefixer postcss plugin, so you'll also have to run:

npm install autoprefixer @types/autoprefixer --save-dev

This plugin requires Node.js 14 or higher. For older Node versions, see the 1.x release.

stencil.config.ts

import { Config } from '@stencil/core';
import { postcss } from '@stencil/postcss';
import autoprefixer from 'autoprefixer';

export const config: Config = {
  plugins: [
    postcss({
      plugins: [autoprefixer()]
    })
  ]
};

During development, this plugin will use postcss to process any plugins you may have passed along.

Options

Postcss has an ecosystem of plugins itself (a plugin for a plugin if you will). For our example, we're using the autoprefixer plugin, and configuring its options. Note, you can pass any valid autoprefixer option.

exports.config = {
  plugins: [
    postcss({
      plugins: [
        autoprefixer({
          browsers: ['last 6 versions'],
          cascade: false
        })
      ]
    })
  ]
};

Inject Globals Paths

The injectGlobalPaths config is an array of paths that automatically get added as @import declarations to all components. This can be useful to inject variables, mixins and functions to override defaults of external collections. Relative paths within injectGlobalPaths should be relative to the stencil.config.js file.

exports.config = {
  plugins: [
    postcss({
      injectGlobalPaths: [
        'src/globals/variables.pcss',
        'src/globals/mixins.pcss'
      ]
    })
  ]
};

Note that each of these files are always added to each component, so in most cases they shouldn't contain CSS because it'll get duplicated in each component. Instead, injectGlobalPaths should only be used for Sass variables, mixins and functions, but not contain any CSS.

Valid file extensions

This plugin will only transpile files whose extensions are .css, .pcss, or .postcss.

Related

Contributing

Please see our Contributor Code of Conduct for information on our rules of conduct.