A plugin for PostCSS that generates px or rpx units from rem units.
- Rewrite with
typescript
and well tested. - Support
Postcss7
andPostcss8
! - TransformUnit Support
px
andrpx
! (for those miniprogram developers who use my tailwindcss-miniprogram-preset)
$ yarn add -D postcss-rem-to-responsive-pixel
// postcss 8:
require('postcss-rem-to-responsive-pixel')
// postcss 7:
require('postcss-rem-to-responsive-pixel/postcss7')
When you use tailwindcss
to write your website or miniprogram(Chinese Developer knows LOL) , the default unit is rem
, so sometimes we have to transform our unit to px
or rpx
.
this plugin use like postcss-rem-to-pixel, all options are compatible !
Thanks to the author of postcss-rem-to-pixel
and postcss-pxtorem
.
if you use with tailwindcss
and tailwindcss-miniprogram-preset
you may should close the rem2rpx in this preset:
// tailwind.config.js
const { createPreset } = require('tailwindcss-miniprogram-preset')
module.exports = {
presets: [
createPreset({
rem2rpx: false,
}),
],
}
and set below options:
// postcss.config.js
module.exports = {
plugins: [
require('autoprefixer'),
require('tailwindcss'),
require('postcss-rem-to-responsive-pixel')({
rootValue: 32,
propList: ['*'],
transformUnit: 'rpx',
}),
],
}
With the default settings, only font related properties are targeted.
// input
h1 {
margin: 0 0 20px;
font-size: 2rem;
line-height: 1.2;
letter-spacing: 0.0625rem;
}
// output
h1 {
margin: 0 0 20px;
font-size: 64rpx;
line-height: 1.2;
letter-spacing: 2rpx;
}
Type: Object | Null
Default:
{
rootValue: 16,
unitPrecision: 5,
propList: ['font', 'font-size', 'line-height', 'letter-spacing'],
selectorBlackList: [],
replace: true,
mediaQuery: false,
minRemValue: 0 ,
exclude: undefined,
transformUnit: 'px'
}
rootValue
(Number) The root element font size.unitPrecision
(Number) The decimal precision px units are allowed to use, floored (rounding down on half).propList
(Array) The properties that can change from rem to px.- Values need to be exact matches.
- Use wildcard
*
to enable all properties. Example:['*']
- Use
*
at the start or end of a word. (['*position*']
will matchbackground-position-y
) - Use
!
to not match a property. Example:['*', '!letter-spacing']
- Combine the "not" prefix with the other prefixes. Example:
['*', '!font*']
selectorBlackList
(Array) The selectors to ignore and leave as rem.- If value is string, it checks to see if selector contains the string.
['body']
will match.body-class
- If value is regexp, it checks to see if the selector matches the regexp.
[/^body$/]
will matchbody
but not.body
- If value is string, it checks to see if selector contains the string.
replace
(Boolean) replaces rules containing rems instead of adding fallbacks.mediaQuery
(Boolean) Allow rem to be converted in media queries.minRemValue
(Number) Set the minimum rem value to replace.exclude
(String, Regexp, Function) The file path to ignore and leave as px.- If value is string, it checks to see if file path contains the string.
'exclude'
will match\project\postcss-pxtorem\exclude\path
- If value is regexp, it checks to see if file path matches the regexp.
/exclude/i
will match\project\postcss-pxtorem\exclude\path
- If value is function, you can use exclude function to return a true and the file will be ignored.
- the callback will pass the file path as a parameter, it should returns a Boolean result.
function (file) { return file.indexOf('exclude') !== -1; }
- If value is string, it checks to see if file path contains the string.
transformUnit
(px
orrpx
) The transform output unit.
// postcss.config.js
module.exports = {
plugins: [
// for example
// require('autoprefixer'),
// require('tailwindcss'),
require('postcss-rem-to-responsive-pixel')({
rootValue: 32,
propList: ['*'],
transformUnit: 'rpx',
}),
],
}
Currently, the easiest way to have a single property ignored is to use a capital in the rem unit declaration.
// `rem` is converted to `px`
.convert {
font-size: 1rem; // converted to 16px
}
// `Rem` or `REM` is ignored by `postcss-rem-to-pixel` but still accepted by browsers
.ignore {
border: 1rem solid; // ignored
border-width: 2rem; // ignored
}