@webcomponents/webcomponentsjs/src/flag-parser.js

Web Components Polyfills

/**
 * @license
 * Copyright (c) 2014 The Polymer Project Authors. All rights reserved.
 * This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
 * The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
 * The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
 * Code distributed by Google as part of the polymer project is also
 * subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
 */

'use strict';

// Establish scope.
window['WebComponents'] = window['WebComponents'] || {'flags':{}};

// loading script
let file = 'webcomponents-bundle';
let script = document.querySelector('script[src*="' + file + '"]');
let flagMatcher = /wc-(.+)/;

// Flags. Convert url arguments to flags
let flags = {};
if (!flags['noOpts']) {
  // from url
  location.search.slice(1).split('&').forEach(function(option) {
    let parts = option.split('=');
    let match;
    if (parts[0] && (match = parts[0].match(flagMatcher))) {
      flags[match[1]] = parts[1] || true;
    }
  });
  // from script
  if (script) {
    for (let i=0, a; (a=script.attributes[i]); i++) {
      if (a.name !== 'src') {
        flags[a.name] = a.value || true;
      }
    }
  }
  // log flags
  if (flags['log'] && flags['log']['split']) {
    let parts = flags['log'].split(',');
    flags['log'] = {};
    parts.forEach(function(f) {
      flags['log'][f] = true;
    });
  } else {
    flags['log'] = {};
  }
}

// exports
window['WebComponents']['flags'] = flags;
let forceShady = flags['shadydom'];
if (forceShady) {
  window['ShadyDOM'] = window['ShadyDOM'] || {};
  window['ShadyDOM']['force'] = forceShady;
}

let forceCE = flags['register'] || flags['ce'];
if (forceCE && window['customElements']) {
  window['customElements']['forcePolyfill'] = forceCE;
}