Angular updating and clearing factory variables

Question

I'm creating a single page app in which a user searches for a term, the result gets saved in a variable, and a new page is routed that displays the result. I have this functionality working, however I want the variable to be cleared when the user returns to the previous page and most importantly when the user logs out. What's the proper way to do this? I want the factory to save things for certain pages that I want, and clear them for certain pages I don't want like "home" or "logout".

Factory:

angular.module('firstApp')
    .factory('fact', function () {
    var service = {};
    var _information = 'Default Info';

    service.setInformation = function(info){
      _information = info;
    }

    service.getInformation = function(){
      return _information;
    }
    return service;
});

Controller:

angular.module('firstApp')
    .controller('InformationCtrl', function($scope, $http, $location, fact) {
        $scope.message = 'Hello';
        $scope.result = fact.getInformation();
        $scope.sub = function(form) {
            console.log($scope.name);
            $scope.submitted = true;
            $http.get('/wiki', {
                params: {
                    name: $scope.name,
                }
            }).success(function(result) {
                console.log("success!");
                $scope.result = result;
                    fact.setInformation(result);
                $location.path('/informationdisplay');
            });;
        }
    });

Routes

angular.module('firstApp')
  .config(function ($routeProvider) {
    $routeProvider
      .when('/information', {
        templateUrl: 'app/information/input.html',
        controller: 'InformationCtrl',
        authenticate : true
      })
        .when('/informationdisplay', {
        templateUrl: 'app/information/results.html',
        controller: 'InformationCtrl',
        authenticate : true
      });
  });

input.html

<div class="row">
    <div class="col-md-6 col-md-offset-3 text-center">
         <p>{{result}}</p>
         <form class="form" name="form" ng-submit="sub(form)" novalidate>
            <input type="text" name="name" placeholder="Name" class="form-control" ng-model="name">
            </br>
            <button class="btn btn-success" type="submit" class="btn btn-info">Check</button>
    </div>
</div>

results.html

<div ng-include="'components/navbar/navbar.html'"></div>
<div class="row">
    <div class="col-sm-4 col-sm-offset-4">
            <h2>Information Results</h2>
            <p>{{result}}</p>   
    </div>
  </div>
</div>

Answer 1

If you want it to wipe the value when they change routes (which logout should change routes also, I assume), you can watch the $routeChangeStart event and have it wipe the value whenever it occurs. You put that function in the module.run block:

app.run(function ($rootScope, fact) { 
    $rootScope.$on("$routeChangeStart",function(event, next, current){
        fact.setInformation(null);
    });
});