fela-dom/es/dom/connection/insertRule.js

Fela package for working with the DOM

import { generateCSSRule, generateCSSSupportRule, getRuleScore } from 'fela-utils';
export default function insertRule(_ref, renderer, node) {
  var selector = _ref.selector,
      declaration = _ref.declaration,
      support = _ref.support,
      media = _ref.media,
      pseudo = _ref.pseudo;
  var nodeReference = media + support;

  try {
    var score = getRuleScore(renderer.ruleOrder, pseudo);
    var cssRules = node.sheet.cssRules;
    var index = cssRules.length; // This heavily optimises the amount of rule iterations we need
    // due to most rules having a score=0 anyways

    if (score === 0) {
      if (renderer.scoreIndex[nodeReference] === undefined) {
        index = 0;
      } else {
        index = renderer.scoreIndex[nodeReference] + 1;
      }
    } else {
      // we start iterating from the last score=0 entry
      // to correctly inject pseudo classes etc.
      var startIndex = renderer.scoreIndex[nodeReference] || 0;

      for (var i = startIndex, len = cssRules.length; i < len; ++i) {
        if (cssRules[i].score > score) {
          index = i;
          break;
        }
      }
    }

    var cssRule = generateCSSRule(selector, declaration);

    if (support.length > 0) {
      var cssSupportRule = generateCSSSupportRule(support, cssRule);
      node.sheet.insertRule(cssSupportRule, index);
    } else {
      node.sheet.insertRule(cssRule, index);
    }

    if (score === 0) {
      renderer.scoreIndex[nodeReference] = index;
    }

    cssRules[index].score = score;
  } catch (e) {// We're disabled these warnings due to false-positive errors with browser prefixes
    // See https://github.com/robinweser/fela/issues/634
    // console.warn(
    //   `An error occurred while inserting the rules into DOM.\n`,
    //   declaration.replace(/;/g, ';\n'),
    //   e
    // )
  }
}