persistence.js

'use strict';
angular.module("elven")
.factory("persistence", function($q) {
  var geoRef = new Firebase('https://elvenapp.firebaseio.com/geo'),
      ref    = new geoFire(geoRef);

  return {
    store: function(id, coords, user) {
      var defered = $q.defer();
      this.location = coords;
      ref.insertByLocWithId([coords.lat, coords.lng], id, user || {}, function(error) {
        if (error) {
          defered.reject(error);
        } else {
          defered.resolve();
        }
      });
      return defered.promise;
    },
    update: function(id, coords) {
      var defered = $q.defer();
      this.location = coords;
      ref.updateLocForId([coords.lat, coords.lng], id, function(error) {
        if (error) {
          defered.reject(error);
        } else {
          defered.resolve();
        }
      });
      return defered.promise;
    },
    geo: ref,
    getById: function(id) {
      var defered = $q.defer();
      ref.getLocById(id, function(latLong) {
        if (latLong) {
          defered.resolve({ lat: latLong[0], lng: latLong[1]});
        } else {
          defered.reject();
        }
      });

      return defered.promise;
    }
  };
});