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      1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 'use strict';
      6 
      7 
      8 /**
      9  * The global object.
     10  * @type {!Object}
     11  * @const
     12  */
     13 var global = this;
     14 
     15 
     16 /** Platform, package, object property, and Event support. */
     17 this.base = (function() {
     18 
     19   function mLog(text, opt_indentLevel) {
     20     if (true)
     21       return;
     22 
     23     var spacing = '';
     24     var indentLevel = opt_indentLevel || 0;
     25     for (var i = 0; i < indentLevel; i++)
     26       spacing += ' ';
     27     console.log(spacing + text);
     28   }
     29 
     30   /**
     31    * Builds an object structure for the provided namespace path,
     32    * ensuring that names that already exist are not overwritten. For
     33    * example:
     34    * 'a.b.c' -> a = {};a.b={};a.b.c={};
     35    * @param {string} name Name of the object that this file defines.
     36    * @param {*=} opt_object The object to expose at the end of the path.
     37    * @param {Object=} opt_objectToExportTo The object to add the path to;
     38    *     default is {@code global}.
     39    * @private
     40    */
     41   function exportPath(name, opt_object, opt_objectToExportTo) {
     42     var parts = name.split('.');
     43     var cur = opt_objectToExportTo || global;
     44 
     45     for (var part; parts.length && (part = parts.shift());) {
     46       if (!parts.length && opt_object !== undefined) {
     47         // last part and we have an object; use it
     48         cur[part] = opt_object;
     49       } else if (part in cur) {
     50         cur = cur[part];
     51       } else {
     52         cur = cur[part] = {};
     53       }
     54     }
     55     return cur;
     56   }
     57 
     58   function exportTo(namespace, fn) {
     59     var obj = exportPath(namespace);
     60     try {
     61       var exports = fn();
     62     } catch (e) {
     63       console.log('While running exports for ', name, ':');
     64       console.log(e.stack || e);
     65       return;
     66     }
     67 
     68     for (var propertyName in exports) {
     69       // Maybe we should check the prototype chain here? The current usage
     70       // pattern is always using an object literal so we only care about own
     71       // properties.
     72       var propertyDescriptor = Object.getOwnPropertyDescriptor(exports,
     73                                                                propertyName);
     74       if (propertyDescriptor) {
     75         Object.defineProperty(obj, propertyName, propertyDescriptor);
     76         mLog('  +' + propertyName);
     77       }
     78     }
     79   }
     80 
     81   return {
     82     exportTo: exportTo
     83   };
     84 })();