ramnathv/knitr — comment on commit c3375ee1c17c7b709295bdd66ffdf6a2e7eef8cd
File: R/themes.R line 3
By yihui:

I'm not worried by parsing css files. I'm worried by having to download files every time.

The other thing is the user may not have write access to the knitr package after it is installed, because it may be installed by the system admin (in our department it is often the case), so I prefer parsing a URL directly to a theme list, which can be cached so next time I do not have to download the xml file again.