Multiple fetch calls result in unnecessary downloads

[akshaybadola]

Sometimes a pdf file takes a long time to download and as a consequence a user can call it again. That results in redundancy as a PDF file is then downloaded again needlessly. There needs to be flag with a timeout which checks if the last call is finished and a way for the user to abort the download also.

• We can do with a progress meter of download but I'm not sure if that's supported by url-retrieve.

• So upon a quick search, there's a make-progress-reporter and progress-reporter update function which can be used

  (defun show-progress-demo ()
    (interactive)
    (let ((download-reporter
           (make-progress-reporter "Downloading python documentation..."
                                   0  100)))
      (url-retrieve "http://www.google.com"
                    (lambda (data bar)
                      ;; skip http header
                      (re-search-forward "\r?\n\r?\n")
                      (write-region (point) (point-max) "/tmp/google")
                      (progress-reporter-done bar))
                      `(,download-reporter))
      (dotimes (k 100)
        (sit-for 0.01)
        (progress-reporter-update download-reporter k))))