Writing text to a dedicated buffer

Writing text to a dedicated buffer

[Christopher Dimech]

I am writing text to a package dedicated buffer.  Is this the way to
go about doing that.  Or are there neater ways?


(defun gungadin-guidance-message ()
   "Displays embedded rudimentary help for gungadin.
Gungadin forms part of Behistun, a Gnu Package."

   (let ((out-buffer (get-buffer-create "*Gungadin*")))
     (with-current-buffer out-buffer
       (insert "\nGungadin\n\n")
       (insert "Gungadin is part of Behistun, a Gnu Package.\n\n")
       (insert "Gungadin 1.0 of 2017-05-02")
       (insert "\nCopyright (C) 2017 Christopher Dimech\n")
       (insert "\nAuthor: Christopher Dimech")

       (insert gungadin-guidance-message)
       (pop-to-buffer out-buffer))) )

Re: Writing text to a dedicated buffer

[Christopher Dimech]

I would like to write more things to the created buffer from
other functions.  Not so sure if it is good to call get-buffer-create
on the created buffer every time I want to write to it.

Is there some good scheme for writing to a user defined buffer from
various elisp files?


> Sent: Monday, May 03, 2021 at 12:48 AM
> From: "Christopher Dimech" <dimech@gmx.com>
> To: "Help Gnu Emacs" <help-gnu-emacs@gnu.org>
> Subject: Writing text to a dedicated buffer
>
> I am writing text to a package dedicated buffer.  Is this the way to
> go about doing that.  Or are there neater ways?
>
>
> (defun gungadin-guidance-message ()
>    "Displays embedded rudimentary help for gungadin.
> Gungadin forms part of Behistun, a Gnu Package."
>
>    (let ((out-buffer (get-buffer-create "*Gungadin*")))
>      (with-current-buffer out-buffer
>        (insert "\nGungadin\n\n")
>        (insert "Gungadin is part of Behistun, a Gnu Package.\n\n")
>        (insert "Gungadin 1.0 of 2017-05-02")
>        (insert "\nCopyright (C) 2017 Christopher Dimech\n")
>        (insert "\nAuthor: Christopher Dimech")
>
>        (insert gungadin-guidance-message)
>        (pop-to-buffer out-buffer))) )
>
>
>

Re: Writing text to a dedicated buffer

[Emanuel Berg via Users list for the GNU Emacs text editor]

Christopher Dimech wrote:

> I would like to write more things to the created buffer from
> other functions. Not so sure if it is good to call
> get-buffer-create on the created buffer every time I want to
> write to it.

Why not?

Write one function to write, then everyone else who has
something to say calls that function.

-- 
underground experts united
https://dataswamp.org/~incal

Re: Writing text to a dedicated buffer

[Christopher Dimech]

I have done the writing to a dedicated buffer as follows,
using "gungadin-bufr-insert" for writing to the Gungadin buffer.

-------- code --------

(setq gungadin-bufr (generate-new-buffer "*Gungadin*"))

(defvar gungadin-guidance-message
  "C-h f flight\n")

(defun gungadin-guidance-message ()
   "Displays embedded rudimentary help for gungadin in a dedicated buffer."

   (message "%s" gungadin-guidance-message)

   (let (($out-buffer (get-buffer-create "*Gungadin*")))
     (with-current-buffer $out-buffer
       (insert "\nGungadin\n\n")
       (insert "Gungadin is part of Behistun, a Gnu Package.\n\n")
       (insert "Gungadin 1.0 of 2017-05-02\n")
       (insert "Copyright (C) 2017 Christopher Dimech\n\n")
       (insert "Author: Christopher Dimech\n\n")

       (insert gungadin-guidance-message)
       (pop-to-buffer $out-buffer))) )

;; (switch-to-buffer GdBfr)

(defun gungadin-bufr-insert (format-string)
   "Display a message at the bottom of the Gungadin Buffer."

   (set-buffer gungadin-bufr)
   (with-current-buffer gungadin-bufr
     (insert format-string)) )

(gungadin-guidance-message)
(gungadin-bufr-insert "***** TEST")





> Sent: Monday, May 03, 2021 at 12:48 AM
> From: "Christopher Dimech" <dimech@gmx.com>
> To: "Help Gnu Emacs" <help-gnu-emacs@gnu.org>
> Subject: Writing text to a dedicated buffer
>
> I am writing text to a package dedicated buffer.  Is this the way to
> go about doing that.  Or are there neater ways?
>
>
> (defun gungadin-guidance-message ()
>    "Displays embedded rudimentary help for gungadin.
> Gungadin forms part of Behistun, a Gnu Package."
>
>    (let ((out-buffer (get-buffer-create "*Gungadin*")))
>      (with-current-buffer out-buffer
>        (insert "\nGungadin\n\n")
>        (insert "Gungadin is part of Behistun, a Gnu Package.\n\n")
>        (insert "Gungadin 1.0 of 2017-05-02")
>        (insert "\nCopyright (C) 2017 Christopher Dimech\n")
>        (insert "\nAuthor: Christopher Dimech")
>
>        (insert gungadin-guidance-message)
>        (pop-to-buffer out-buffer))) )
>
>
>

Re: Writing text to a dedicated buffer

[Joost Kremers]

On Sun, May 02 2021, Christopher Dimech wrote:
> I have done the writing to a dedicated buffer as follows,
> using "gungadin-bufr-insert" for writing to the Gungadin buffer.
>
> -------- code --------
>
> (setq gungadin-bufr (generate-new-buffer "*Gungadin*"))

This should be a `defvar`. Personally, I would probably initialise it to
`nil` and create a buffer on the first call to `gungadin-bufr-insert`. But more
likely, I would probably do something like this:

(defvar gungadin-buffer-name "*Gungadin*")

(defun gungadin-buffer-insert (message)
  (with-current-buffer (get-buffer-create gungadin-buffer-name)
    ...)) 

There is no problem calling `get-buffer-create` on a buffer that already exists.
Just make sure you pass it the name of the buffer, not the buffer object itself,
because in the latter case you may get back a dead buffer which you cannot write
to anymore. (You never know when a user accidentally kills the Gungadin buffer.)
Do `C-h f get-buffer-create RET` for details.

> (defun gungadin-bufr-insert (format-string)
>    "Display a message at the bottom of the Gungadin Buffer."
>
>    (set-buffer gungadin-bufr)
>    (with-current-buffer gungadin-bufr
>      (insert format-string)) )

If you check the source code of `with-current-buffer`, you'll notice that it
uses `set-buffer`. There is no need to call `set-buffer` if you're going to use
`with-current-buffer`. (And you should be using `with-current-buffer`.)


-- 
Joost Kremers
Life has its moments

Re: Writing text to a dedicated buffer

[Emanuel Berg via Users list for the GNU Emacs text editor]

Christopher Dimech wrote:

> I am writing text to a package dedicated buffer. Is this the
> way to go about doing that. Or are there neater ways?
>
>    (let ((out-buffer (get-buffer-create "*Gungadin*")))
>      (with-current-buffer out-buffer

Where did you get that code? :)

But to answer your question with a question, what not neat
with that?

Looks good to me. Ha :)

-- 
underground experts united
https://dataswamp.org/~incal

Re: Writing text to a dedicated buffer

[Filipp Gunbin]

On 02/05/2021 14:48 +0200, Christopher Dimech wrote:

> I am writing text to a package dedicated buffer.  Is this the way to
> go about doing that.  Or are there neater ways?

Check out with-output-to-temp-buffer, looks like it fits your use case.

Filipp