# Cache logic in js\_include\_tag and stylesheet\_link\_tag? **URL:** \ **Category:** Rails\ **Created:** [April 27, 2010, 9:20pm UTC](https://www.ruby-forum.com/t/cache-logic-in-js-include-tag-and-stylesheet-link-tag/187690 "2010-04-27T21:20:15Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![jrochkind](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/779978/32.png) [@jrochkind](https://www.ruby-forum.com/u/jrochkind)\ **Post date:** [April 27, 2010, 9:20pm UTC](https://www.ruby-forum.com/t/cache-logic-in-js-include-tag-and-stylesheet-link-tag/187690/1 "2010-04-27T21:20:15Z")
So using the magic :cache argument to combine multiple CSS or JS files into one cached file, using stylesheet\_link\_tag or javascript\_include\_tag respectively… I sort of figured that if the arguments to the function changed, including different files… the combined cached file would be re-generated. This does not seem to be the case. javascript\_include\_tag “a”, “b”, :cache =\> “my\_key” Stop application. Edit the code to be: javascript\_include\_tag “a”, “b”, “c”, :cache =\> “my\_key” Restart the application. Run it. The combined cached my\_key.js file still only includes “a” and “b”, the cached file was not invalidated when I added “c” to it. I had to go and find the file and rm it myself. Is this a bug? Or is this expected behavior? Is there something I’m missing? Under what circumstances is the cached file supposed to be regenerated? If the last-modified timestamp changes on one of the included files, will it be regenerated? Will it EVER be re-generated? ---
**Author:** ![jrochkind](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/779978/32.png) [@jrochkind](https://www.ruby-forum.com/u/jrochkind)\ **Post date:** [April 29, 2010, 8:57pm UTC](https://www.ruby-forum.com/t/cache-logic-in-js-include-tag-and-stylesheet-link-tag/187690/2 "2010-04-29T20:57:37Z")
Jonathan R. wrote: > Is this a bug? Or is this expected behavior? Is there something I’m > missing? Under what circumstances is the cached file supposed to be > regenerated? If the last-modified timestamp changes on one of the > included files, will it be regenerated? Will it EVER be re-generated? I see the same behavior, and I basically use the same solution. Probably not a bad idea to add a step to your Capistrano (or whatever deploy tool) to delete those files on each deployment. ---
**Author:** ![jrochkind](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/779978/32.png) [@jrochkind](https://www.ruby-forum.com/u/jrochkind)\ **Post date:** [April 29, 2010, 9:05pm UTC](https://www.ruby-forum.com/t/cache-logic-in-js-include-tag-and-stylesheet-link-tag/187690/3 "2010-04-29T21:05:42Z")
Robert W. wrote: > Jonathan R. wrote: > > > Is this a bug? Or is this expected behavior? Is there something I’m > > missing? Under what circumstances is the cached file supposed to be > > regenerated? If the last-modified timestamp changes on one of the > > included files, will it be regenerated? Will it EVER be re-generated? > > I see the same behavior, and I basically use the same solution. Probably > not a bad idea to add a step to your Capistrano (or whatever deploy > tool) to delete those files on each deployment. Thanks for the response. I’m thinking this is a bug, and I’ll try to go ahead and file it in the tracker, although I lack the Rails fu to fix it myself. In the absence of a fix, could also add something to your Rails app startup routines to delete the files, to work regardless of Capistrano use or not. ---
**Author:** ![jrochkind](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/779978/32.png) [@jrochkind](https://www.ruby-forum.com/u/jrochkind)\ **Post date:** [April 30, 2010, 7:54pm UTC](https://www.ruby-forum.com/t/cache-logic-in-js-include-tag-and-stylesheet-link-tag/187690/4 "2010-04-30T19:54:48Z")
Hi Jonathan Read this also. [http://maintainable.com/articles/rails\_asset\_cache](http://maintainable.com/articles/rails_asset_cache) If any modification happens to js or css as specified, then before next release you can apply this trick Sijo