Awesome
postcss-font-family-system-ui <img src="https://postcss.github.io/postcss/logo.svg" alt="PostCSS Logo" width="90" height="90" align="right">
postcss-font-family-system-ui lets you use system-ui
in CSS, following the
CSS Fonts Module Level 4 specification.
body {
font: 100%/1.5 system-ui;
}
/* becomes */
body {
font: 100%/1.5 system-ui, -apple-system, Segoe UI, Roboto, Noto Sans, Ubuntu,
Cantarell, Helvetica Neue;
}
Usage
Add postcss-font-family-system-ui to your build tool:
npm install postcss postcss-font-family-system-ui --save-dev
PostCSS
Add PostCSS to your build tool:
npm install postcss --save-dev
Use postcss-font-family-system-ui as a plugin:
import postcss from "gulp-postcss";
import postcssSystemUiFont from "postcss-font-family-system-ui";
postcss([postcssSystemUiFont(/* options */)]).process(YOUR_CSS);
Gulp
Add Gulp PostCSS to your build tool:
npm install gulp-postcss --save-dev
Use postcss-font-family-system-ui in your Gulpfile:
import postcss from "gulp-postcss";
import postcssSystemUiFont from "postcss-font-family-system-ui";
gulp.task("css", () =>
gulp
.src("./src/*.css")
.pipe(postcss([postcssSystemUiFont(/* options */)]))
.pipe(gulp.dest("."))
);
Grunt
Add Grunt PostCSS to your build tool:
npm install grunt-postcss --save-dev
Use postcss-font-family-system-ui in your Gruntfile:
import postcssSystemUiFont from "postcss-font-family-system-ui";
grunt.loadNpmTasks("grunt-postcss");
grunt.initConfig({
postcss: {
options: {
use: [postcssSystemUiFont(/* options */)],
},
dist: {
src: "*.css",
},
},
});
Options
family
The family
option defines the fallback families used to polyfill system-ui
.
It accepts an array or a comma-separated string.
import postcssSystemUiFont from "postcss-font-family-system-ui";
postcssSystemUiFont({
family: "system-ui, Segoe UI, Roboto, Helvetica Neue", // use less fallbacks
});
browsers
Note: if family
option is specified, the browsers
option will not be activated.
The browsers
option determines the supported browsers, which is used to tune levels of polyfill based on the support matrix of system-ui
at caniuse.
postcss-font-family-system-ui supports any standard browserslist configuration, which includes a .browserslistrc
file, a browserslist
key in package.json
, or browserslist
environment variables.
The browsers
option should only be used when a standard browserslist configuration is not available.
postcssSystemUiFont({
browsers: ["last 2 versions"],
});
If not valid browserslist configuration is specified, the default browserslist query will be used.
preserve
The preserve: boolean
option controls whether system-ui
should be preserved in the transformed CSS output.
It accepts only boolean and the default is true
postcssSystemUiFont({
preserve: true, // preserve `system-ui` in the transpiled output
});
Note that if your browserslist
config targets to browsers which have native support of system-ui
, this option will be a no-op.
postcssSystemUiFont({
browsers: ["Chrome 60"], // Chrome 60 has native system-ui support
preserve: false, // the `system-ui` will still be preserved when it is not polyfilled
});