Factory to create multiple DocumentDB clients

docDBFactory.js

var AzureDbHelper = require('./azureDbHelper.js'),
	config = require('../config.js');

module.exports = (function DbHelperFactory(){
	var postsCollectionHelper;
	var fanPostsCollectionHelper;
	var concertsCollectionHelper;
	
	return{
		getPostsHelper: function getPostsHelper(){
			if(!postsCollectionHelper){
				postsCollectionHelper = new AzureDbHelper(config.db_options.databases.main,
				config.db_options.collections.postsCollection);
			}
			return postsCollectionHelper;
		},
		getFanPostsHelper: function getFanPostsHelper(){
			if(!fanPostsCollectionHelper){
				fanPostsCollectionHelper = new AzureDbHelper(config.db_options.databases.main,
					config.db_options.collections.fanPostsCollection);
			}
			return fanPostsCollectionHelper;
		},
		getConcertsHelper: function getConcertsHelper(){
			if(!concertsCollectionHelper){
				concertsCollectionHelper = new AzureDbHelper(config.db_options.databases.main,
					config.db_options.collections.concerts);
			}
			return concertsCollectionHelper;
		}
	}
})();