Flask/Werkzeug how to attach HTTP content-length header to file download

Jon Cox picture Jon Cox · Sep 28, 2010 · Viewed 24.3k times · Source

I am using Flask (based on Werkzeug) which uses Python.

The user can download a file, I'm using the send_from_directory-function.

However when actually downloading the file, the HTTP header content-length is not set. So the user has no idea how big the file being downloaded is.

I can use os.path.getsize(FILE_LOCATION) in Python to get the file size (in bytes), but cannot find a way to set the content-length header in Flask.

Any ideas?

Answer

Cyril N. picture Cyril N. · Mar 28, 2012

I needed this also, but for every requests, so here's what I did (based on the doc) :

@app.after_request
def after_request(response):
    response.headers.add('Access-Control-Allow-Origin', '*')
    return response