File downloads with TurboGears

In TurboGears, I had to implement a file download method, but the file required access controls so it was put in a directory not exported by Apache.

In #turbogears I've been pointed at: http://cherrypy.org/wiki/FileDownload and this is everything put together:

from cherrypy.lib.cptools import serveFile
# In cherrypy 3 it should be:
#from cherrypy.lib.static import serve_file

@expose()
def get(self, *args, **kw):
    """Access the file pointed by the given path"""
    pathname = check_auth_and_compute_pathname()
    return serveFile(pathname)

Then I needed to export some CSV:

@expose()
def getcsv(self, *args, **kw):
    """Get the data in CSV format"""
    rows = compute_data_rows()
    headers = compute_headers(rows)
    filename = compute_file_name()

    cherrypy.response.headers['Content-Type'] = "application/x-download"
    cherrypy.response.headers['Content-Disposition'] = 'attachment; filename="'+filename+'"'

    csvdata = StringIO.StringIO()
    writer = csv.writer(csvdata)
    writer.writerow(headers)
    writer.writerows(rows)

    return csvdata.getvalue()

In my case it's not an issue as I can only compute the headers after I computed all the data, but I still have to find out how to serve the CSV file while I'm generating it, instead of storing it all into a big string and returning the big string.