Re: [QUESTION] Re: [PATCH] make org-attach-url download function as an option

[Ihor Radchenko]

I do not know an answer to your question, but would like to point out
that make-thread will return immidietealy and all the following code
will run before the download finishes:

(run-hook-with-args 'org-attach-after-change-hook attach-dir)
(org-attach-tag)
(cond ((eq org-attach-store-link-p 'attached)...

At least the hooks and org-attach-tag would expect that the file is
attached already.

Best,
Ihor

stardiviner <numbchild@gmail.com> writes:

> I got solution for async org-attach-url now. Use `make-thread` for async
> downloading is simple.
>
> Here is the code prototype, but it has a problem, seems `apply` part code does
> not really downloading file. I don't know why. Does anybody knows the reason?
>
> #+begin_src diff
> modified   lisp/org-attach.el
> @@ -110,6 +110,12 @@ (defcustom org-attach-method 'cp
>         (const :tag "Hard Link" ln)
>         (const :tag "Symbol Link" lns)))
>  
> +(defcustom org-attach-url-function 'url-copy-file
> +  "The download file function to use in org-attach-url."
> +  :type '(choice (const 'url-copy-file))
> +  :safe #'functionp
> +  :group 'org-attach)
> +
>  (defcustom org-attach-expert nil
>    "Non-nil means do not show the splash buffer with the attach dispatcher."
>    :group 'org-attach
> @@ -503,7 +509,12 @@ (defun org-attach-attach (file &optional visit-dir 
> method)
>         ((eq method 'cp) (copy-file file attach-file))
>         ((eq method 'ln) (add-name-to-file file attach-file))
>         ((eq method 'lns) (make-symbolic-link file attach-file))
> -       ((eq method 'url) (url-copy-file file attach-file)))
> +       ((eq method 'url) (make-thread
> +                       (lambda ()
> +                         ;; (url-copy-file file attach-file)
> +                         ;; FIXME This seems does not really download file. 
> Don't know why.
> +                         (apply org-attach-url-function '(file attach-file)))
> +                       "org-attach-url downloading")))
>        (run-hook-with-args 'org-attach-after-change-hook attach-dir)
>        (org-attach-tag)
>        (cond ((eq org-attach-store-link-p 'attached)
> #+end_src
>
> Bastien <bzg@gnu.org> writes:
>
>> Hi,
>>
>> stardiviner <numbchild@gmail.com> writes:
>>
>>> I found when network is bad and slow, or the download file is big, the
>>> org-attach-url will suspend Emacs for a long time. User might have to cancel
>>> downloading, and start again later.
>>
>> Indeed, this might be annoying.  At the same time, it is not
>> unreasonable to expect the user to know what size is the contents he
>> is willing to attach to an Org node.
>>
>>> I hope to make "org-attach-url" download file asynchronously. But function
>>> org-attach-attach hardcoded this function for 'url method. Here is a patch 
>>> to
>>> make it into an option.
>>
>> (FWIW, I could not find the patch.)
>>
>> I think you are on the right track when trying to enhance the 'url
>> package.  Maybe url-copy-file should be asynchronous and url could
>> provide url-copy-file-synchronously (to mimic the url-retrieve and
>> url-retrieve-synchronously pair)?
>>
>> Until Emacs has a function to copy a URL's contents asynchronously,
>> I'd rather not add this functionality in Org.
>
>
> -- 
> [ stardiviner ]
>        I try to make every word tell the meaning that I want to express.
>
>        Blog: https://stardiviner.github.io/
>        IRC(freenode): stardiviner, Matrix: stardiviner
>        GPG: F09F650D7D674819892591401B5DF1C95AE89AC3
>

-- 
Ihor Radchenko,
PhD,
Center for Advancing Materials Performance from the Nanoscale (CAMP-nano)
State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong 
University, Xi'an, China
Email: yantar92@gmail.com, ihor_radchenko@alumni.sutd.edu.sg