CODEWITHSUNDEEP
javascriptlocal-storage
Tychus
Tychus

Reputation: 189

Sharing storage between instances of same web app

I built a web application that i have running on multiple raspberry pis, I wanted to add storage that is shared by all the web app instances. Basically what I want to achieve is for each instance I open in my browser it saves the device name and URL to my browser (Local storage is what I went with but it's not shared) the web app would then open the storage read all previously accessed pis for easy switching.

I tried to do this using local storage but didn't work as apparently it's per instance and not shared. anyone can suggest a proper way to achieve this ?

Upvotes: 0

Views: 2652

Answers (3)

Bergi
Bergi

Reputation: 664513

Local storage is local to the current domain. There is no storage that can freely be shared between all web pages built into a browser.

If you have multiple web applications / application instances, they need to know about each other to communicate (via cross-frame messaging) and exchange their URLs to have each store them locally and display them. There are a few approaches how to do that:

  • have the user explicitly add other domains he knows about so that you can contact them
  • have the servers announce their presence on the local network (or use a configuration file on each server) so that they know about each other before serving the web site
  • have a central ("storage") website at a known domain that every application website will contact

Upvotes: 0

Our_Benefactors
Our_Benefactors

Reputation: 3539

Local storage keys are shared on a single device if requests originate on the same domain.

Consider the following example of how keys could be shared:

You have the domain http://example.com

You have two apps hosted at http://example.com/app1/index.html and http://example.com/app2/index.html

You have a local storage key for last visited where the value is a date string

If you go to app1, it sets the key.

If you go to app2, it will be able to retrieve the key set in app1.

Are you having trouble with getting localstorage to be shared across instances in this manner?

If the apps are on different domains, or you're trying to share information between devices, you'll have to use a server to share the data.

Upvotes: 0

hon2a
hon2a

Reputation: 7214

Local storage is exactly as it sounds - local to the browser (and machine). It's used to store data between multiple sessions with the same app/website on the same machine/browser. If you want to share some information between multiple instances of the app running on different machines or in multiple different browsers you need to store it on the server.

How to store it on the server is then a separate question alltogether (with a wide range of options, e.g. writing to a file or a database). In any case, the implementation will need to be separate from the client app.

Upvotes: 1

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