A db enums module

controller.js

// An example of a controller that would require the enums
var enums = require('./enums')(); // Get a singleton

/**
 * Assuming a page isn't served before the asynchronous data is returned
 * this should give us cached data
 */
var get = function(req, res) {
  res.render('page', { tags: enums.getTags() });
}

enums.js

var 
  models = require('../models')
, utils = require('../utils');

/**
 * Database enumerations for various lists such
 * tags, meal styles, etc. Implemented with the 
 * singleton pattern.
 *
 * http://addyosmani.com/resources/essentialjsdesignpatterns/book/#singletonpatternjavascript
 */
var enums = (function() {

  // Store a reference to this singleton
  var instance;

  var init = function() {

    // Private data
    var tags;

    models.Tag.find({}, function(err, results) {
      tags = utils.invoke(results, 'toJSON');
    });

    // Public methods and variables
    return {
      getTags: function() {
        return tags;
      }
    };
  };

  // Only instantiate once
  return function() {
    if(!instance) instance = init();
    return instance;
  };
})();

/**
 * Expose module
 */
module.exports = enums;