make emacs ask to save modified non-file buffers

make emacs ask to save modified non-file buffers

[Xah]

when i create a new buffer, how can i make emacs ask to save if it is
modified?

for example, i have this function:

(defun new-empty-buffer ()
  "Opens a new empty buffer."
  (interactive)
  (let ((buf (generate-new-buffer "untitled")))
    (switch-to-buffer buf)
    (funcall (and initial-major-mode))
    (setq buffer-offer-save t)
))

after calling, it'll create a new buffer. Then, if user edit the
buffer, then close it (using either kill-buffer or kill-this-buffer),
then i want emacs to ask whether to save it if the buffer has been
modified.

according to the manual, the var buffer-offer-save will do it only if
the buffer is a visiting buffer. Then the manual talks about save-some-
buffers second argument but i don't see how this fits together, since
i don't actually want to call save-some-buffers.

Thanks.

  Xah
∑ http://xahlee.org/

☄

Re: make emacs ask to save modified non-file buffers

[Lennart Borgman (gmail)]

Xah wrote:
> when i create a new buffer, how can i make emacs ask to save if it is
> modified?
> 
> for example, i have this function:
> 
> (defun new-empty-buffer ()
>   "Opens a new empty buffer."
>   (interactive)
>   (let ((buf (generate-new-buffer "untitled")))
>     (switch-to-buffer buf)
>     (funcall (and initial-major-mode))
>     (setq buffer-offer-save t)
> ))
> 
> after calling, it'll create a new buffer. Then, if user edit the
> buffer, then close it (using either kill-buffer or kill-this-buffer),
> then i want emacs to ask whether to save it if the buffer has been
> modified.
> 
> according to the manual, the var buffer-offer-save will do it only if
> the buffer is a visiting buffer. Then the manual talks about save-some-
> buffers second argument but i don't see how this fits together, since
> i don't actually want to call save-some-buffers.


(info "(elisp) Killing Buffers")

Re: make emacs ask to save modified non-file buffers

[Xah]

> (info "(elisp) Killing Buffers")

I was already reading that page but it doesn't seems to suggest a
solution.

Namely, how to make kill-buffer ask user to save, for buffers that's
not associated with file.

looking at Aquamacs's source... looks like the “solved” it by actually
define its own kill-buffer wrapper, e.g. close-current-window-
asktosave.

  Xah
∑ http://xahlee.org/

☄


On Jun 22, 5:48 pm, "Lennart Borgman (gmail)"
<lennart.borg...@gmail.com> wrote:
> Xah wrote:
> > when i create a new buffer, how can i make emacs ask to save if it is
> > modified?
>
> > for example, i have this function:
>
> > (defun new-empty-buffer ()
> >   "Opens a new empty buffer."
> >   (interactive)
> >   (let ((buf (generate-new-buffer "untitled")))
> >     (switch-to-buffer buf)
> >     (funcall (and initial-major-mode))
> >     (setq buffer-offer-save t)
> > ))
>
> > after calling, it'll create a new buffer. Then, if user edit the
> > buffer, then close it (using either kill-buffer or kill-this-buffer),
> > then i want emacs to ask whether to save it if the buffer has been
> > modified.
>
> > according to the manual, the var buffer-offer-save will do it only if
> > the buffer is a visiting buffer. Then the manual talks about save-some-
> > buffers second argument but i don't see how this fits together, since
> > i don't actually want to call save-some-buffers.
>

Re: make emacs ask to save modified non-file buffers

[Lennart Borgman (gmail)]

Xah wrote:
>> (info "(elisp) Killing Buffers")
> 
> I was already reading that page but it doesn't seems to suggest a
> solution.

What about the hooks there?

> Namely, how to make kill-buffer ask user to save, for buffers that's
> not associated with file.
> 
> looking at Aquamacs's source... looks like the “solved” it by actually
> define its own kill-buffer wrapper, e.g. close-current-window-
> asktosave.
> 
>   Xah
> ∑ http://xahlee.org/
> 
> ☄
> 
> 
> On Jun 22, 5:48 pm, "Lennart Borgman (gmail)"
> <lennart.borg...@gmail.com> wrote:
>> Xah wrote:
>>> when i create a new buffer, how can i make emacs ask to save if it is
>>> modified?
>>> for example, i have this function:
>>> (defun new-empty-buffer ()
>>>   "Opens a new empty buffer."
>>>   (interactive)
>>>   (let ((buf (generate-new-buffer "untitled")))
>>>     (switch-to-buffer buf)
>>>     (funcall (and initial-major-mode))
>>>     (setq buffer-offer-save t)
>>> ))
>>> after calling, it'll create a new buffer. Then, if user edit the
>>> buffer, then close it (using either kill-buffer or kill-this-buffer),
>>> then i want emacs to ask whether to save it if the buffer has been
>>> modified.
>>> according to the manual, the var buffer-offer-save will do it only if
>>> the buffer is a visiting buffer. Then the manual talks about save-some-
>>> buffers second argument but i don't see how this fits together, since
>>> i don't actually want to call save-some-buffers.
> 

Re: make emacs ask to save modified non-file buffers

[Juanma Barranquero]

On Mon, Jun 23, 2008 at 02:23, Xah <xahlee@gmail.com> wrote:

> according to the manual, the var buffer-offer-save will do it only if
> the buffer is a visiting buffer.

Uh? describe-variable's output for `buffer-offer-save':

  [...]
  Non-nil in a buffer means always offer to save buffer on exit.
  Do so even if the buffer is not visiting a file.    <--- ???????
  [...]

and the Emacs Lisp Reference's entry for `buffer-offer-save':

 -- Variable: buffer-offer-save
     This variable, if non-`nil' in a particular buffer, tells
     `save-buffers-kill-emacs' and `save-some-buffers' (if the second
     optional argument to that function is `t') to offer to save that
     buffer, just as they offer to save file-visiting buffers.   <--- ???????

The problem here is that `buffer-offer-save' affects the two functions
mentioned above (`save-buffers-kill-emacs' and `save-some-buffers'),
not `kill-buffer'. As Lennart says, you'll have to use
`kill-emacs-hook' or `kill-emacs-query-functions' and add a function
to ask the user and save if appropriate.

   Juanma