Util module for working with Firebase & angularFire

fire-util.js

angular.module('fireUtil', ['firebase'])

.provider('fireUtil', function () {
  var util, $get;

  util = {
    rootUrl: null,
    $get: ['Firebase', function (Firebase) {
      var _rootRef = util.rootUrl ? new Firebase(util.rootUrl) : null;

      return {
        ref: _firebaseRef,
        toArray: _angularFireObjectToArray
      };

      /**
       * Firebase reference generator
       *
       * Configure `rootUrl` in configuration phase:
       *
       *   fireUtilProvider.rootUrl = 'https://...';
       *
       * Use it to get Firebase reference in run phase:
       *
       *   fireUtil.ref();  // "{BASE}" reference
       *
       *   fireUtil.ref('a', 'b', 'c');  // "{BASE}/a/b/c" reference
       *   fireUtil.ref(['a', 'b', 'c']);  // same as above
       */
      function _firebaseRef(path) {
        if (!_rootRef) {
          throw new Error('`rootUrl` configuration required.');
        }

        if (!angular.isArray(path)) {
          path = Array.prototype.slice.call(arguments);
        }
        
        if (!path || path.length === 0) {
          return new Firebase(util.rootUrl);
        }
        
        return _rootRef.child(path.join('/'));
      }

      /**
       * Transform an AngularFire object (collection) to an Array object
       *
       * @param  {AngularFire} object              AngularFire object to be transformed
       * @param  {string}      transformedKeyname  key name to be attached into each array element (optional, default "$id")
       * @return {array}                           transformed array
       */
      function _angularFireObjectToArray(object, transformedKeyname) {
        transformedKeyname = transformedKeyname || '$id';

        var l = [];
        angular.forEach(object, function (value, key) {
          var update = {};
          update[transformedKeyname] = key;

          l.push(
            angular.extend({}, value, update)
          );
        });
        return l;
      }
    }]
  };

  return util;
});