svgo-browser/plugins/convertStyleToAttrs.js

svgo tool for browser and node usage

/* jshint quotmark: false */

exports.type = 'perItem';

exports.active = true;

exports.description = 'converts style to attributes';

exports.params = {
  keepImportant: false,
};

const stylingProps = require('./_collections').attrsGroups.presentation;

const rEscape = '\\\\(?:[0-9a-f]{1,6}\\s?|\\r\\n|.)'; // Like \" or \2051. Code points consume one space.
const rAttr = `\\s*(${g('[^:;\\\\]', rEscape)}*?)\\s*`; // attribute name like ‘fill’
const rSingleQuotes = `'(?:[^'\\n\\r\\\\]|${rEscape})*?(?:'|$)`; // string in single quotes: 'smth'
const rQuotes = `"(?:[^"\\n\\r\\\\]|${rEscape})*?(?:"|$)`; // string in double quotes: "smth"
const rQuotedString = new RegExp(`^${g(rSingleQuotes, rQuotes)}$`);
// Parentheses, E.g.: url(data:image/png;base64,iVBO...).
// ':' and ';' inside of it should be threated as is. (Just like in strings.)
const rParenthesis = `\\(${g('[^\'"()\\\\]+', rEscape, rSingleQuotes, rQuotes)}*?` + '\\)';
// The value. It can have strings and parentheses (see above). Fallbacks to anything in case of unexpected input.
const rValue = `\\s*(${
  g('[^!\'"();\\\\]+?', rEscape, rSingleQuotes, rQuotes, rParenthesis, '[^;]*?')
}*?`
    + ')';
  // End of declaration. Spaces outside of capturing groups help to do natural trimming.
const rDeclEnd = '\\s*(?:;\\s*|$)';
// Important rule
const rImportant = '(\\s*!important(?![-(w]))?';
// Final RegExp to parse CSS declarations.
const regDeclarationBlock = new RegExp(`${rAttr}:${rValue}${rImportant}${rDeclEnd}`, 'ig');
// Comments expression. Honors escape sequences and strings.
const regStripComments = new RegExp(g(rEscape, rSingleQuotes, rQuotes, '/\\*[^]*?\\*/'), 'ig');

/**
 * Convert style in attributes. Cleanups comments and illegal declarations (without colon) as a side effect.
 *
 * @example
 * <g style="fill:#000; color: #fff;">
 *             ⬇
 * <g fill="#000" color="#fff">
 *
 * @example
 * <g style="fill:#000; color: #fff; -webkit-blah: blah">
 *             ⬇
 * <g fill="#000" color="#fff" style="-webkit-blah: blah">
 *
 * @param {Object} item current iteration item
 * @return {Boolean} if false, item will be filtered out
 *
 * @author Kir Belevich
 */
exports.fn = function (item, params) {
  /* jshint boss: true */

  if (item.elem && item.hasAttr('style')) {
    // ['opacity: 1', 'color: #000']
    let styleValue = item.attr('style').value;
    let styles = [];
    const attrs = {};

    // Strip CSS comments preserving escape sequences and strings.
    styleValue = styleValue.replace(regStripComments, (match) => (match[0] == '/' ? '' : match[0] == '\\' && /[-g-z]/i.test(match[1]) ? match[1] : match));

    regDeclarationBlock.lastIndex = 0;
    for (var rule; (rule = regDeclarationBlock.exec(styleValue));) {
      if (!params.keepImportant || !rule[3]) {
        styles.push([rule[1], rule[2]]);
      }
    }

    if (styles.length) {
      styles = styles.filter((style) => {
        if (style[0]) {
          const prop = style[0].toLowerCase();
          let val = style[1];

          if (rQuotedString.test(val)) {
            val = val.slice(1, -1);
          }

          if (stylingProps.indexOf(prop) > -1) {
            attrs[prop] = {
              name: prop,
              value: val,
              local: prop,
              prefix: '',
            };

            return false;
          }
        }

        return true;
      });

      Object.assign(item.attrs, attrs);

      if (styles.length) {
        item.attr('style').value = styles
          .map((declaration) => declaration.join(':'))
          .join(';');
      } else {
        item.removeAttr('style');
      }
    }
  }
};

function g() {
  return `(?:${Array.prototype.join.call(arguments, '|')})`;
}