Force browser to clear cache

Question

Is there a way I can put some code on my page so when someone visits a site, it clears the browser cache, so they can view the changes?

Languages used: ASP.NET, VB.N

Answer 1

I had similiar problem and this is how I solved it:

1. In index.html file I've added manifest:

2. In section included script updating the cache:

3. In section I've inserted onload function:

4. In cache.manifest I've put all files I want to cache. It is important now that it works in my case (Apache) just by updating each time the "version" comment. It is also an option to name files with "?ver=001" or something at the end of name but it's not needed. Changing just # version 1.01 triggers cache update event.

   CACHE MANIFEST
   # version 1.01
   style.css
   imgs/logo.png
   #all other files
   

   It's important to include 1., 2. and 3. points only in index.html. Otherwise

   GET http://foo.bar/resource.ext net::ERR_FAILED
   

   occurs because every "child" file tries to cache the page while the page is already cached.

5. In update_cache.js file I've put this code:

   function checkForUpdate()
   {
       if (window.applicationCache != undefined && window.applicationCache != null)
       {
           window.applicationCache.addEventListener('updateready', updateApplication);
       }
   }
   function updateApplication(event)
   {
       if (window.applicationCache.status != 4) return;
       window.applicationCache.removeEventListener('updateready', updateApplication);
       window.applicationCache.swapCache();
       window.location.reload();
   }
   

Now you just change files and in manifest you have to update version comment. Now visiting index.html page will update the cache.

The parts of solution aren't mine but I've found them through internet and put together so that it works.