pxtorem-dpr

A postcss plugin that calculates and generates adaptive css code, such as rem and 0.5px borders for retina devices.

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Table of Contents

• Requirements
• Usage
• Changelog
• License

Requirements

Set rem unit and hairline class. For example:

(function (win, doc) {
  var docEl = doc.documentElement;

  function setRemUnit () {
    var docWidth = docEl.clientWidth;
    var rem = docWidth / 10;
    docEl.style.fontSize = rem + 'px';
  }

  win.addEventListener('resize', function () {
    setRemUnit();
  }, false);
  win.addEventListener('pageshow', function (e) {
    if (e.persisted) {
      setRemUnit();
    }
  }, false);

  setRemUnit();

  if (win.devicePixelRatio && win.devicePixelRatio >= 2) {
    var testEl = doc.createElement('div');
    var fakeBody = doc.createElement('body');
    testEl.style.border = '0.5px solid transparent';
    fakeBody.appendChild(testEl);
    docEl.appendChild(fakeBody);
    if (testEl.offsetHeight === 1) {
      docEl.classList.add('hairlines');
    }
    docEl.removeChild(fakeBody);
  }
}) (window, document);

Or use amfe-flexible

Usage

The raw stylesheet only contains @2x style, and if you

• intend to use rem unit，add /*rem*/ after the declaration
• don't intend to transform the original value, add /*no*/ after the declaration
• intend to use px unit when autoRem is set to true, add /*px*/ after the declaration

Attention: Dealing with SASS or LESS, only /*...*/ comment can be used, in order to have the comments persisted.

Before processing:

.selector {
  height: 64px;
  width: 150px; /*rem*/
  padding: 10px; /*no*/
  border-top: 1px solid #ddd;
}

After processing:

.selector {
  height: 32px;
  width: 2rem;
  padding: 10px;
  border-top: 1px solid #ddd;
}
.hairlines .selector {
  border-top: 0.5px solid #ddd;
}

API

adaptive(config)

Config:

• remUnit: number, rem unit value (default: 75)

• baseDpr: number, base device pixel ratio (default: 2)

• remPrecision: number, rem value precision (default: 6)

• hairlineSelector: string, selector name of 1px border (default '.hairlines') Example: '[data-dpr="2"],[data-dpr="3"]'

• autoRem: boolean, whether to transform to rem unit (default: true)

• propList: array, The properties that can use transform (default: ['*'])

  • 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']

• pxPropList: array, The properties that can change from px to dpr (default: ['font*', 'border*', '!border-radius'])

  • 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']

• selectorBlackList: array, The selectors to ignore and leave as px. (default: [])

  • 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

• exclude: array, The selectors to ignore file. (default: null)

  • If value is string, it checks to see if selector contains the string. Example: ['node_modules']
  • If value is regexp, it checks to see if the selector matches the regexp.

License

MIT