Save Javascript objects in sessionStorage

Question

SessionStorage and LocalStorage allows to save key/value pairs in a web browser. The value must be a string, and save js objects is not trivial.

var user = {         


        

Answer 1

Either you can use the accessors provided by the Web Storage API or you could write a wrapper/adapter. From your stated issue with defineGetter/defineSetter is sounds like writing a wrapper/adapter is too much work for you.

I honestly don't know what to tell you. Maybe you could reevaluate your opinion of what is a "ridiculous limitation". The Web Storage API is just what it's supposed to be, a key/value store.

Answer 2

Use case:

 sesssionStorage.setObj(1,{date:Date.now(),action:'save firstObject'});
 sesssionStorage.setObj(2,{date:Date.now(),action:'save 2nd object'}); 
 //Query first object
  sesssionStorage.getObj(1)
  //Retrieve date created of 2nd object
  new Date(sesssionStorage.getObj(1).date)

API

Storage.prototype.setObj = function(key, obj) {

        return this.setItem(key, JSON.stringify(obj))
    };
    
    Storage.prototype.getObj = function(key) {
        return JSON.parse(this.getItem(key))
    };

Answer 3

    var user = {'name':'John'};
    sessionStorage['user'] = JSON.stringify(user);
    console.log(sessionStorage['user']);

Answer 4

Session storage cannot support an arbitrary object because it may contain function literals (read closures) which cannot be reconstructed after a page reload.

Answer 5

You could also use the store library which performs it for you with crossbrowser ability.

example :

// Store current user
store.set('user', { name:'Marcus' })

// Get current user
store.get('user')

// Remove current user
store.remove('user')

// Clear all keys
store.clearAll()

// Loop over all stored values
store.each(function(value, key) {
    console.log(key, '==', value)
})

Answer 6

The solution is to stringify the object before calling setItem on the sessionStorage.

var user = {'name':'John'};
sessionStorage.setItem('user', JSON.stringify(user));
var obj = JSON.parse(sessionStorage.user);