Class CSSRule

engine/cssparser.js:40–121

const isspace = c => c === ' ' || c === '\n';

export class CSSRule {
  static {
    this.prototype.type = RuleType.None;
  }
  selectors = [];
  properties = {};

  static parseSelector(input) {
    input = input.trim()
      .replaceAll('\r\n', '\n'); // normalize newlines

    const out = [];

    for (let x of input.split(',')) {
      x = x.trim();

      let cType = CombinatorType.Descendant;
      let sType = SelectorType.Tag;
      let text = '';

      const sels = [];
      let conds = [];

      const pushCond = () => {
        if (text || sType === SelectorType.Universal) conds.push({ type: sType, text });
        sType = SelectorType.Tag;
        text = '';
      };

      const isCombinator = c => [' ', '>'].includes(c);

      for (let i = 0; i < x.length; i++) {
        const c = x[i];

        if (isCombinator(c) && text && (c !== ' ' || (!isCombinator(x[i + 1]) && !isspace(x[i + 1])))) {
          pushCond();

          sels.push({ type: cType, conds });
          conds = [];

          if (c === ' ') cType = CombinatorType.Descendant;
          if (c === '>') cType = CombinatorType.Child;

          continue;
        }

        if (['#', '.', '*', ':'].includes(c) || i === x.length - 1) {
          if (i === x.length - 1) text += c;

          if (c === '*') sType = SelectorType.Universal;
          pushCond();

          if (c === '#') sType = SelectorType.Id;
          if (c === '.') sType = SelectorType.Class;
          if (c === ':') sType = SelectorType.Pseudo;

          continue;
        }