Getting information about static files in Python App Engine; workarounds

Question

I'm working on an App Engine project that will have customizable themes. I'd like to be able to use jQuery UI themes. The problem is figuring out what the CSS file is going to be named. (Typically, "jquery-ui-1.7.2.custom.css". Version numbers will change, and people tend to rename things, but there should only be one CSS file, and I'm OK with it being an error condition if there's two or more for some reason.) Because it's a static file (static files are uploaded to App Engine separately from the rest of the application's resources), I can't just glob the directory for a CSS file. I can't just assume that it's hard-coded, and I really don't want to make it a configuration setting, because that's a bad user experience.

Guido told me to symlink it so that App Engine sees two copies and can treat one as static and the other as an application resource, but symlinks don't work on Windows, and since this will ultimately be open source, I can't control which SDK the user uses. Another suggestion was to use a deploy-time script, but Mac users have this nice "Deploy" button in their version of the SDK and I'd rather not have to tell them, "Oh hey, sorry for the inconvenience, but you can't use that for this project."

I clearly need an out-of-the-box solution to this one, but I'm at a loss. Anyone have any good suggestions for how to get a custom jQuery UI theme out of the ThemeRoller and into an App Engine app? Some post-processing is already needed, because the only files in the zip file that ThemeRoller gives you are in the "css" directory. Maybe I can write something that takes a raw theme as input and spits out something useful on the other side (the deploy-time script trick, but somehow less user-unfriendly). The trick here is presentation — I want the user to spend as little time on the command line as possible. An ideal solution assumes the person performing this task is non-technical for the most part. No part of the solution can be much harder than installing something like WordPress or Drupal, and in a perfect world, it should be way, way easier.

Answer 1

To accomplish what you are asking, I would use the datastore for serving the CSS files. Since this would allow easy listing, sorting and even modification and uploading.

Other than that, your next best options would be to store the CSS data inside a script (a dictionary where the filename is the key name, and the CSS code is the value). Or, as you suggested, to run a script before deploying to AppEngine.

Personally, I would go for the storing in the datastore option, since it will allow for a great deal more user customization (such as each user being able to provide their own CSS file), just be sure to use memcache to avoid needing to access the datastore when possible (which should be a very common occurrence), as well as using HTTP headers to tell the browser to cache the CSS file locally.