I am currently implementing CSS file bundling in a way that uses a virtual path to a PHP file, as such:
~/bundle/bundle.css&cssFolders=... => ~/bundle/bundle.php&type=css&cssFolders=...
Since I provide paths to my CSS folders, a bundle URL may look like this:
My bundle file then builds the resulting CSS content by importing all files that it finds, for instance:
@import url("../css/x.css"); @import url("../shared/css/y.css");
The solution, however, did only work in some cases, and failed for others. I was confused before I found the solution.
The / chars in the URL query makes the @import statement fail, since it seems to count all / in the URL, not just all the / in the path excluding the query. This is quite understandable, since css files are not meant to handle query variables.
In this case, however, we have a virtual css file that handles query variables, which is why we need to solve this problem.
The solution, in this case, is to count the number of / in the query variable
cssFolders and add an extra ../ for each additional / in the import statements.