Changes to the Layouts folder do not apply

Question

The problem:

In Visual studio I created a Mapped folder - Layouts. In it I have subfolders and one of them is js (full with javascript files). In that folder I have the scripts.js file. I include this file in the masterpage and deploy the project - the file loads ok and is accessable (no problems there). Then I needed to make changes to it and added them. When I deployed (full deploy) those changes are not there (it still loads the old content).

Additional info:

-All the paths to the file are ok and the correct file is loaded.

-No cache involved (I deleted it) - still the same.

-SharePoint is 2013, VS 2013 as well (if that could matter).

Edit 1:

I went to the file system ..../15/.../js and found the file. It is the latest version with the changes. I rechecked the paths in the master page and the cache - the problem is not there.

I used the design manager to create the masterpage from html. Could this cause such problems.

Any ideas?

Answer 1

Caching on SharePoint is a tricky thing. I have also experienced this behaviour, when the file was refreshed on the filesystem, I could see the changes in it if I opened it on the server, but web browsers were retrieving the old (chached) version, even if I pressed CTRL+F5.

Later edit: I have experienced this odd caching even if we performed IISRESET during the deployment of the new files. It was simply independent of the server, it was the cache of each and every user's browser. We could have either sent out a communication, that they should clear their cache or press CTRL+F5, but that would have seemed pretty unprofessional from the IT department. We also analyzed the possibility of creating a policy which would force everyones browser to clear its cache, but the network team objected, that this would cause an unnecesary and high traffic, because thousand of users would download again the files from the servers, and most of those haven't even changed. Cuasing all the fuss just for one or two files out of 15-20 was not making sense. End of later edit

Fortunately, there is a simple solution to this: whenever you change a js, css or even an image file, add a diferent revision number to its URL. For example:

Version 1 --> <script src="/_layouts/js/script.js?v=1"></script>

Version 2 --> <script src="/_layouts/js/script.js?v=2"></script>

You can add anything in the querystring, it can be a hash of the file, a guid, just make sure that it will be different whenever the file changes. (And it would be nice if you would make sure that the query string changes only when the content of the file really changes, else you force the browser to retrieve the file from the server fot nothing). Sharepoint is already doing this. If you observe the corev4.css or sp.js references, they all have a revision number in the querystring.

You can obtain this revision number easily by using a method in SPUtility, which works only for files on the file system (which is your case) which generates a correct revision number for the referenced files. Please check SPUtility.MakeBrowserCacheSafeLayoutsUrl and this other stackexchange post for more details.

Later edit: as it seems from some of the comments in the linked post, MakeBrowserCacheSafeLayoutsUrl is not always working as expected. I haven't used it in production yet, so I can't confirm or deny this. But we have succesfully used version numbers in production environment, the version being generated via a script during build by TFS. But you can also update the version by hand whenever you change the content. And this is guaranteed to work everytime, no need to clear the browser cache, and it works for both files on the file system and the content database (like references from style library)

Answer 2

You need to do IISReset and it will load the new JS file.. Also make sure you press Ctrl + F5 on browser for complete reload..

PS: Please make sure you perform IISReset in off business hours (if in Production).. If its development environment, you are good to go..

Answer 3

Right Click on Internet Explorer and Select In Private Browsing. It will make sure latest .js files are loaded.

Answer 4

its not the masterpage as the masterpage only stores the url location of the js file! and its not the location of the js files themselfs! As you noted they are updated correctly! You could do an iisreset but that is over the top especially if its on a live server or on a test server thats used internally! the issue lies with the browser as all are correct appart from seeing the old js within the browser! I usualy hit ctrl + f5 as that usually works to fully refresh the page. If its still cashing the js than you need to go into developer tools (f12) for ie or firebug ect and clear the browser cashe:

tools -> developer tools (f12) -> wait for it to load -> under html tab you should see a box with a red x witin bottom right.. click that and reload page using ctrl + f5