Web caching when retrieving lists of documents

We need to use client-side resources for lists containing tasks.

The client must:

• receive notifications about updates in the list
• be able to reorder / filter the list (request an update from the server with tasks that the client does not know / has in the cache)

The problem occurs on bootstrap or large list updates (going from "assigned to me tasks" to "tasks relative to x")

The quickest thing to do is put all tasks back in the list, not individual (10+) requests.

But E-tags won't help when I request to update a task in the list, since it was not downloaded separately.

Is there a way to force the browser to cache the items in the list against their individual urls?

Or a way to create a javascript cache that will stay away from navigation?

• If I step aside and go to the task url, will my js objects survive? I suspect not.
• If I step aside and then cast back, will my javascript objects survive? I suspect so.
  • If so, is it possible to have a "load task list" page that will check the history and return to the existing task list? I think no - security.

I think I just need to do the bootstrap and fetch jobs individually so that later requests are fast (and take the load off the server).