[session] Maintaining Session through Angular.js

I am working a project using the AngularJS framework. I am pretty new to using this framework; in the past I have only worked with pure JavaScript and jQuery. The project is a kind of web designer application for a niche market.

As the user moves between pages while designing I want to maintain a session of all the changes they are making.

Now if the user signs in we load the session using data from the database. When the user clicks on save button we update the database with the session data. Someone told me that I can maintain session in Angular similar to backbone. Is this possible? If yes, can you please direct me to a tutorial that does not focus on directives or UI? If this is not possible are there other viable options?

This question is related to session angularjs

The answer is


You would use a service for that in Angular. A service is a function you register with Angular, and that functions job is to return an object which will live until the browser is closed/refreshed. So it's a good place to store state in, and to synchronize that state with the server asynchronously as that state changes.


Because the answer is no longer valid with a more stable version of angular, I am posting a newer solution.

PHP Page: session.php

if (!isset($_SESSION))
{    
    session_start();
}    

$_SESSION['variable'] = "hello world";

$sessions = array();

$sessions['variable'] = $_SESSION['variable'];

header('Content-Type: application/json');
echo json_encode($sessions);

Send back only the session variables you want in Angular not all of them don't want to expose more than what is needed.

JS All Together

var app = angular.module('StarterApp', []);
app.controller("AppCtrl", ['$rootScope', 'Session', function($rootScope, Session) {      
    Session.then(function(response){
        $rootScope.session = response;
    });
}]);

 app.factory('Session', function($http) {    
    return $http.get('/session.php').then(function(result) {       
        return result.data; 
    });
}); 
  • Do a simple get to get sessions using a factory.
  • If you want to make it post to make the page not visible when you just go to it in the browser you can, I'm just simplifying it
  • Add the factory to the controller
  • I use rootScope because it is a session variable that I use throughout all my code.

HTML

Inside your html you can reference your session

<html ng-app="StarterApp">

<body ng-controller="AppCtrl">
{{ session.variable }}
</body>

You can also try to make service based on window.sessionStorage or window.localStorage to keep state information between page reloads. I use it in the web app which is partially made in AngularJS and page URL is changed in "the old way" for some parts of workflow. Web storage is supported even by IE8. Here is angular-webstorage for convenience.


Typically for a use case which involves a sequence of pages and in the final stage or page we post the data to the server. In this scenario we need to maintain the state. In the below snippet we maintain the state on the client side

As mentioned in the above post. The session is created using the factory recipe.

Client side session can be maintained using the value provider recipe as well.

Please refer to my post for the complete details. session-tracking-in-angularjs

Let's take an example of a shopping cart which we need to maintain across various pages / angularjs controller.

In typical shopping cart we buy products on various product / category pages and keep updating the cart. Here are the steps.

Here we create the custom injectable service having a cart inside using the "value provider recipe".

'use strict';
function Cart() {
    return {
        'cartId': '',
        'cartItem': []
    };
}
// custom service maintains the cart along with its behavior to clear itself , create new , delete Item or update cart 

app.value('sessionService', {
    cart: new Cart(),
    clear: function () {
        this.cart = new Cart();
        // mechanism to create the cart id 
        this.cart.cartId = 1;
    },
    save: function (session) {
        this.cart = session.cart;
    },
    updateCart: function (productId, productQty) {
        this.cart.cartItem.push({
            'productId': productId,
            'productQty': productQty
        });
    },
    //deleteItem and other cart operations function goes here...
});