PostCSS is a tool for transforming styles with JS plugins. In Webpacker you can configure the plugins and their settings via the postcss.config.js file. Make sure that postcss-loader is part of your package.json.
module.exports = {
plugins: [
require('postcss-import'),
require('postcss-flexbugs-fixes'),
require('postcss-preset-env')({
autoprefixer: {
flexbox: 'no-2009'
},
stage: 3
})
]
}
Note: Stage 3 Show archive.org snapshot means you can use all CSS features that are listed as "This idea is becoming part of the web". Do not use standards in any stage before (like 2, 1 or 0).
Run NODE_ENV=production rake assets:precompile to get compiled output in public/packs.
Check the following transformations to ensure you settings are applied. Remove public/packs afterwards again.
CSSnext
Input:
body {
font-variant: small-caps;
background-image: image-set(url(test_1.svg) 1x, url(test_2.svg) 2x);
}
Output:
body {
-webkit-font-feature-settings: "c2sc";
font-feature-settings: "c2sc";
font-variant: small-caps;
background-image: -webkit-image-set(url(test_1.svg) 1x, url((test_2.svg) 2x);
background-image: image-set(url(test_1.svg) 1x, url(test_2.svg);
}
Autoprefixer
Input:
body {
::placeholder {
color: gray;
}
}
Output:
body {
::-webkit-input-placeholder {
color: gray;
}
:-ms-input-placeholder {
color: gray;
}
::-ms-input-placeholder {
color: gray;
}
::placeholder {
color: gray;
}
}
Posted by Emanuel to makandra dev (2019-05-02 07:48)