Service for Restoring Scope: this one uses $location instead of $route

restoreScope.js

angular.module('restoreScope', []).factory('restoreScope', ['$rootScope', '$location', function ($rootScope, $location) {

    var currentScope = null;

    var getOrRegisterScopeVariable = function (scope, name, defaultValue, storedScope) {
        if (storedScope[name] == null) {
            storedScope[name] = defaultValue;
        }
        scope[name] = storedScope[name];
    }

    var service = {

        GetOrRegisterScopeVariables: function (names, defaultValues, scope) {
            currentScope = scope;
            var storedBaseScope = angular.fromJson(sessionStorage.restoreScope);
            if (storedBaseScope == null) {
                storedBaseScope = {};
            }
            // stored scope is indexed by route name
            var storedScope = storedBaseScope[$location.url()];
            if (storedScope == null) {
                storedScope = {};
            }
            if (typeof names === "string") {
                getOrRegisterScopeVariable(scope, names, defaultValues, storedScope);
            } else if (Array.isArray(names)) {
                angular.forEach(names, function (name, i) {
                    getOrRegisterScopeVariable(scope, name, defaultValues[i], storedScope);
                });
            } else {
                console.error("First argument to GetOrRegisterScopeVariables is not a string or array");
            }
            // save stored scope back off
            storedBaseScope[$location.url()] = storedScope;
            sessionStorage.restoreScope = angular.toJson(storedBaseScope);
        },

        SaveState: function () {
            var storedBaseScope = angular.fromJson(sessionStorage.restoreScope);

            // save off scope based on registered indexes
            angular.forEach(storedBaseScope[$location.url()], function (item, i) {
                storedBaseScope[$location.url()][i] = currentScope[i];
            });

            sessionStorage.restoreScope = angular.toJson(storedBaseScope);
        }
    }

    $rootScope.$on("savestate", service.SaveState);

    return service;
}]);