PostCSS Calc [][PostCSS]

[![NPM Version][npm-img]][npm-url]
[![Support Chat][git-img]][git-url]

[PostCSS Calc] lets you reduce calc() references whenever it's possible.
When multiple units are mixed together in the same expression, the calc()
statement is left as is, to fallback to the [W3C calc() implementation].

Installation

``bash
npm install postcss-calc
`

Usage

`js
// dependencies
var fs = require("fs")
var postcss = require("postcss")
var calc = require("postcss-calc")

// css to be processed
var css = fs.readFileSync("input.css", "utf8")

// process css
var output = postcss()
.use(calc())
.process(css)
.css
`

Using this input.css:

`css
h1 {
font-size: calc(16px * 2);
height: calc(100px - 2em);
width: calc(2*var(--base-width));
margin-bottom: calc(16px * 1.5);
}
`

you will get:

`css
h1 {
font-size: 32px;
height: calc(100px - 2em);
width: calc(2*var(--base-width));
margin-bottom: 24px
}
`
Checkout [tests] for more examples.

$3

#### precision (default: 5)

Allow you to define the precision for decimal numbers.

`js
var out = postcss()
.use(calc({precision: 10}))
.process(css)
.css
`

#### preserve (default: false)

Allow you to preserve calc() usage in output so browsers will handle decimal
precision themselves.

`js
var out = postcss()
.use(calc({preserve: true}))
.process(css)
.css
`

#### warnWhenCannotResolve (default: false)

Adds warnings when calc() are not reduced to a single value.

`js
var out = postcss()
.use(calc({warnWhenCannotResolve: true}))
.process(css)
.css
`

#### mediaQueries (default: false)

Allows calc() usage as part of media query declarations.

`js
var out = postcss()
.use(calc({mediaQueries: true}))
.process(css)
.css
`

#### selectors (default: false)

Allows calc() usage as part of selectors.

`js
var out = postcss()
.use(calc({selectors: true}))
.process(css)
.css
`

Example:

`css
div[data-size="calc(3*3)"] {
width: 100px;
}
`

---

Related PostCSS plugins

`bash
git clone git@github.com:postcss/postcss-calc.git
git checkout -b patch-1
npm install
npm test
``

Changelog

License

[git-img]: https://img.shields.io/badge/support-chat-blue.svg
[git-url]: https://gitter.im/postcss/postcss
[npm-img]: https://img.shields.io/npm/v/postcss-calc.svg
[npm-url]: https://www.npmjs.com/package/postcss-calc

[PostCSS]: https://github.com/postcss
[PostCSS Calc]: https://github.com/postcss/postcss-calc
[PostCSS Custom Properties]: https://github.com/postcss/postcss-custom-properties
[tests]: src/__tests__/index.js
[W3C calc() implementation]: https://www.w3.org/TR/css3-values/#calc-notation