Postcss-relaxed-unit 🍮

Postcss-relaxed-unit is a postcss plugin for unit tranformation and make write css easier with custom unit.

You can define a rule to determine the mapping relationship between custom unit and target unit, and you can use some operators to calculate the target value (like add, sub, mul, div, unit), so you can write style relaxed without care about calculate unit.

Motivation

Sometimes, we need to care about calculating the style values, for example, px to rem， rem to vw , px to whatever that mobile side need and we don't need many plugins. so, postcss-relaxed-unit can help you forget that, you just need define a rule that describes the custom unit to target unit mapping! that's all! 🎉

Precision overflow 👌

You don't have to care about precision overflow, because postcss-relaxed-unit wraps bignumber.js.

Install

postcss-relaxed-unit is publish to npm，so you can install it using npm or yarn

npm i postcss-relaxed-unit -D

yarn add postcss-relaxed-unit -D

because postcss-relaxed-unit is depends on PostCSS, you need to install postcss.

Usage

You only need to define rule to get start~

postcss.config.js

const RelaxedUnit = require("postcss-relaxed-unit");

module.exports = {
  plugins: [
    RelaxedUnit({
      rules: { rx: "add(1).sub(2).mul(3).div(9).unit(rem)" }
    })
  ]
};

Multiple rules

You can define more rules :)

const RelaxedUnit = require("postcss-relaxed-unit");

module.exports = {
  plugins: [
    RelaxedUnit({
      rules: {
        rx: "add(1).sub(2).mul(3).div(9).unit(rem)",
        ex: "div(100).unit(rem)"
      }
    })
  ]
};

Nuxt

In Nuxt.js, you need to define the config in nuxt.config.js

nuxt.config.js

module.exports = {
 	build: {
    extractCSS: true,
    postcss: {
      plugins: {
        'postcss-relaxed-unit': {
          rules: { rx: 'div(100).unit(rem)' },
        },
    },
  },
}

Options

rules {[custom unit name]: 'operators'} custom unit to target unit mapping container
add Operator target value plus +
sub Operator target value subtraction -
mul Operator target value multiplication *
div Operator target value divition /
unit Operator unit of output

custom unit will output does not change missing unit Operator, e.g.

{
  "postcss-relaxed-unit": {
    "rules": { "rx": "add(10).sub(2)" }
  }
}

origin style

.hello-relaxed-unit {
  width: 10rx;
}

output style

.hello-relaxed-unit {
  width: 18rx;
}

The signature of operator function like

type OperatorFunction = (arg: number | string) => string;

so, if you call the operator function like add(aas) , it will compile passing, the aas wiil be convert to 0.

{"rx": "add(aas).unit(px)"} => {"rx": "add(0).unit(px)"}

Example

run yarn example or npm run example if you want to see the results of postcss-relaxed-unit working.⚙️

LICENSE

MIT.