react-addons/lib/copyProperties.js

Simple packaging of react addons to avoid fiddly 'react/addons' npm module.

/**
 * Copyright 2013-2014 Facebook, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * @providesModule copyProperties
 */

/**
 * Copy properties from one or more objects (up to 5) into the first object.
 * This is a shallow copy. It mutates the first object and also returns it.
 *
 * NOTE: `arguments` has a very significant performance penalty, which is why
 * we don't support unlimited arguments.
 */
function copyProperties(obj, a, b, c, d, e, f) {
  obj = obj || {};

  if ("production" !== process.env.NODE_ENV) {
    if (f) {
      throw new Error('Too many arguments passed to copyProperties');
    }
  }

  var args = [a, b, c, d, e];
  var ii = 0, v;
  while (args[ii]) {
    v = args[ii++];
    for (var k in v) {
      obj[k] = v[k];
    }

    // IE ignores toString in object iteration.. See:
    // webreflection.blogspot.com/2007/07/quick-fix-internet-explorer-and.html
    if (v.hasOwnProperty && v.hasOwnProperty('toString') &&
        (typeof v.toString != 'undefined') && (obj.toString !== v.toString)) {
      obj.toString = v.toString;
    }
  }

  return obj;
}

module.exports = copyProperties;