svgo-browser/plugins/cleanupEnableBackground.js

svgo tool for browser and node usage

exports.type = 'full';

exports.active = true;

exports.description = 'remove or cleanup enable-background attribute when possible';

/**
 * Remove or cleanup enable-background attr which coincides with a width/height box.
 *
 * @see http://www.w3.org/TR/SVG/filters.html#EnableBackgroundProperty
 *
 * @example
 * <svg width="100" height="50" enable-background="new 0 0 100 50">
 *             ⬇
 * <svg width="100" height="50">
 *
 * @param {Object} item current iteration item
 * @return {Boolean} if false, item will be filtered out
 *
 * @author Kir Belevich
 */
exports.fn = function (data) {
  const regEnableBackground = /^new\s0\s0\s([\-+]?\d*\.?\d+([eE][\-+]?\d+)?)\s([\-+]?\d*\.?\d+([eE][\-+]?\d+)?)$/;
  let hasFilter = false;
  const elems = ['svg', 'mask', 'pattern'];

  function checkEnableBackground(item) {
    if (
      item.isElem(elems)
      && item.hasAttr('enable-background')
      && item.hasAttr('width')
      && item.hasAttr('height')
    ) {
      const match = item.attr('enable-background').value.match(regEnableBackground);

      if (match) {
        if (item.attr('width').value === match[1] && item.attr('height').value === match[3]) {
          if (item.isElem('svg')) {
            item.removeAttr('enable-background');
          } else {
            item.attr('enable-background').value = 'new';
          }
        }
      }
    }
  }

  function checkForFilter(item) {
    if (item.isElem('filter')) {
      hasFilter = true;
    }
  }

  function monkeys(items, fn) {
    items.content.forEach((item) => {
      fn(item);

      if (item.content) {
        monkeys(item, fn);
      }
    });
    return items;
  }

  const firstStep = monkeys(data, (item) => {
    checkEnableBackground(item);
    if (!hasFilter) {
      checkForFilter(item);
    }
  });

  return hasFilter
    ? firstStep
    : monkeys(firstStep, (item) => {
      // we don't need 'enable-background' if we have no filters
      item.removeAttr('enable-background');
    });
};