postcss-pixel-to-remvw

a postcss plugin for converting px to rem and vw, also you can choose only convert one of then.

This version requires postcss version 8

For postcss v7, you have to use postcss-pixel-to-remvw v1

Install

npm install postcss-pixel-to-remvw -D

Example

normal

• Input

h1 {
  margin: 0 0 20px 20px;
  font-size: 32px;
  line-height: 1.2;
  letter-spacing: 1px;
}

• Output

h1 {
  margin: 0 0 0.26667rem 0.26667rem;
  margin: 0 0 2.66667vw 2.66667vw;
  font-size: 0.42667rem;
  font-size: 4.26667vw;
  line-height: 1.2;
  letter-spacing: 0.01333rem;
  letter-spacing: 0.13333vw;
}

not convert to vw (compact with the pc)

• Input

/*disable-convert-vw*/
h1 {
  margin: 0 0 20px 20px;
  font-size: 32px;
  line-height: 1.2;
  letter-spacing: 1px;
}

• Output

/*disable-convert-vw*/
h1 {
  margin: 0 0 0.26667rem 0.26667rem;
  font-size: 0.42667rem;
  line-height: 1.2;
  letter-spacing: 0.01333rem;
}

not convert some

• Input

/*disable-convert-vw*/
h1 {
  margin: 0 0 20px 20px;
  font-size: 32px; /*no*/
  line-height: 1.2;
  letter-spacing: 1px;
}

• Output

/*disable-convert-vw*/
h1 {
  margin: 0 0 0.26667rem 0.26667rem;
  font-size: 32px; /*no*/
  line-height: 1.2;
  letter-spacing: 0.01333rem;
}

Usage

In Webpack

export default {
  module: {
    loaders: [
      {
        test: /\.css$/,
        loader: [
          'style-loader',
          'css-loader',
          {
            loader: 'postcss-loader',
            options: {
              postcssOptions: {
                plugins: [
                  [
                    'postcss-pixel-to-remvw',
                    {
                      // Options
                    },
                  ],
                ],
              },
            },
          },
        ],
      },
    ],
  },
};

common usage

const { writeFile, readFileSync } = require('fs');
const postcss = require('postcss');
const pxtoremvw = require('postcss-pixel-to-remvw');

const processedCss = postcss(pxtoremvw()).process(readFileSync('test.css')).css;

writeFile('test.remvw.css', processedCss, err => {
  if (err) throw err;
  console.log('Rem file written.');
});

Configuration

default:

{
  baseSize: {
    rem: 75, // 10rem = 750px
    vw: 7.5, // 100vw = 750px
  },
  unitPrecision: 5,
  selectorBlackList: [],
  propList: ['*'],
  minPixelValue: 0,
  exclude: null,
  // Single rule does not convert
  keepRuleComment: 'no',
  // The entire file is not converted
  commentOfDisableAll: 'disable-convert',
  // The entire file is not converted to rem
  commentOfDisableRem: 'disable-convert-rem',
  // nThe entire file is not converted to vw
  commentOfDisableVW: 'disable-convert-vw',
};

• baseSize {Object} the base size config, default is { rem: 75, vw: 7.5 }
  • rem {Number | undefined} the root element font size, means 1rem = [your setting] px; It won't convert to rem while rem is undefined
  • vw {Number | undefined} the base ratio for viewport width, means 1vw = [your setting] px; It won't convert to vw while vw is undefined
• unitPrecision {Number} the digital accurarcy of converted stylesheet
• selectorBlackList {string[]} The selectors list to ignore conversion
  • 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 match body but not .body
• propList {string[]} The properties that can do the conversion.
  • Values need to be exact matches.
  • Use wildcard _ to enable all properties. Example: ['_']
  • Use * at the start or end of a word. (['*position*'] will match background-position-y)
  • Use ! to not match a property. Example: ['*', '!letter-spacing']
  • Combine the "not" prefix with the other prefixes. Example: ['', '!font']
• minPixelValue {Number} the minimum pixel value to replace
• exclude {String | Regexp | ()=>boolean} the file path to ignore conversion
  • 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; }
• keepRuleComment {String} a comment stating that the property will not be converted
• commentOfDisableAll {String} a comment stating that the whole file will not be converted
• commentOfDisableRem {String} a comment stating that the whole file will not be converted to rem,but keep convert to vw
• commentOfDisableVW {String} a comment stating that the whole file will not be converted to vw,but keep convert to rem

TODO

• compact with older version of postcss
• unit test
  • baseSize
  • keepRuleComment
  • commentOfDisableAll
  • commentOfDisableRem
  • commentOfDisableVW
  • unitPrecision
  • selectorBlackList
  • propList
  • minPixelValue
  • exclude

Thanks to postcss-pxtorem