Question

188

Pure Javascript - store object in cookie

rated 0 times [ 191] [ 3] / answers: 1 / hits: 108540 / 12 Years ago, thu, july 5, 2012, 12:00:00

No jQuery.

I want to store an object or array in a cookie.

The object should be usable after page refresh.

How do I do that with pure JavaScript? I read many posts, but do not know how to serialize appropriately.

EDIT:
Code:

var instances = {};

...

instances[strInstanceId] = { container: oContainer };

...

instances[strInstanceId].plugin = oPlugin;

...

JSON.stringify(instances); 

// throws error 'TypeError: Converting circular structure to JSON'

How do I serialize instances?

How do I maintain functionality, but change structure of instance to be able to serialize with stringify?

Answers

Only authorized users can answer the question. Please sign in first, or register a free account.

jacie

Add To Favorites

Follow

Total Points: 490

Total Questions: 111

Total Answers: 105

Location: Mali

Member since Sat, Feb 12, 2022

2 Years ago

answered 12 Years ago blaisep · Accepted Answer

Try that one to write

function bake_cookie(name, value) {

  var cookie = [name, '=', JSON.stringify(value), '; domain=.', window.location.host.toString(), '; path=/;'].join('');

  document.cookie = cookie;

}

To read it take:

function read_cookie(name) {

 var result = document.cookie.match(new RegExp(name + '=([^;]+)'));

 result && (result = JSON.parse(result[1]));

 return result;

}

To delete it take:

function delete_cookie(name) {

  document.cookie = [name, '=; expires=Thu, 01-Jan-1970 00:00:01 GMT; path=/; domain=.', window.location.host.toString()].join('');

}

To serialize complex objects / instances, why not write a data dump function in your instance:

function userConstructor(name, street, city) {

   // ... your code

   this.dumpData = function() {

     return {

        'userConstructorUser': {

            name: this.name,

            street: this.street,

            city: this.city

         }

       }

    }

Then you dump the data, stringify it, write it to the cookie, and next time you want to use it just go:

  var mydata = JSON.parse(read_cookie('myinstances'));

  new userConstructor(mydata.name, mydata.street, mydata.city);