Images with Fanstatic and Flask

Question

I got Fanstatic working well with Flask for CSS and JS. The library will allow you to generate hashed file names with a hash. If the hash of click.js is a0sd2lfu12v18fhac4ias0o7if then you can render click-a0sd2lfu12v18fhac4ias0o7if.js in your flask application. The purpose of this is to invalidate browser and CDN cache. When the contents of the file change, so does the name of the file.

I need a library that generates hashes for my images like Fanstatic does for CSS/JS so that when I update my images and deploy to production the browser uses the new image.

The docs for Fanstatic mention it can serve images but it doesn't give any examples. How can I get this hash based file name with my image assets using Flask? If you know how to do this with fanstatic can you please tell me how? If there is a better library to render images with hash based filenames, could you point me in the right direction?

Answer 1

Assuming you have set up the fanstatic Publisher, here's how to compute the URL to resource qux during a request cycle:

import fanstatic
needed = fanstatic.get_needed()
# The NeededResources object is where the configuration 
#(base_url, versionining, etc) is stored during the request.
url = '%s/%s' % (needed.library_url(qux.library), qux.relpath)