follow-mode's use of hooks

follow-mode's use of hooks

[Juanma Barranquero]

I've just fixed follow-mode because it was running hooks twice, which
is a bug (at least, I hope there's no code out there depending on it.)

 (add-hook 'follow-mode-hook
           (lambda () (message "> follow-mode-hook")))

 (add-hook 'follow-mode-off-hook
           (lambda () (message "> follow-mode-off-hook")))

 M-x follow-mode [RET]
   =>
 > follow-mode-hook [2 times]
 Follow mode enabled

 M-x follow-mode [RET]
   =>
 > follow-mode-off-hook
 > follow-mode-hook
 > follow-mode-off-hook
 Follow mode disabled

However, the docstrings for `follow-mode' and `follow-mode-hook' are
still wrong, because they refer to `follow-mode-hook' as if only run
when entering follow-mode (sort of like the non-documented
`follow-mode-on-hook').

I'd be inclined to just apply the following patch, if nobody objects.

             Juanma



Index: lisp/follow.el
===================================================================
RCS file: /sources/emacs/emacs/lisp/follow.el,v
retrieving revision 1.37
diff -u -r1.37 follow.el
--- lisp/follow.el	8 Oct 2007 16:06:15 -0000	1.37
+++ lisp/follow.el	8 Oct 2007 16:24:05 -0000
@@ -278,7 +278,7 @@
   :group 'convenience)

 (defcustom follow-mode-hook nil
-  "Hooks to run when Follow mode is turned on."
+  "Normal hook run by Follow mode."
   :type 'hook
   :group 'follow)

@@ -286,6 +286,7 @@
   "Hooks to run when Follow mode is turned off."
   :type 'hook
   :group 'follow)
+(make-obsolete-variable 'follow-mode-off-hook 'follow-mode-hook "22.2")


 ;;{{{ Keymap/Menu
@@ -517,8 +518,7 @@
 will listen to the output of processes and redisplay accordingly.
 \(This is the default.)

-When Follow mode is switched on, the hook `follow-mode-hook'
-is called.  When turned off, `follow-mode-off-hook' is called.
+This command runs the normal hook `follow-mode-hook'.

 Keys specific to Follow mode:
 \\{follow-mode-map}"

Re: follow-mode's use of hooks

[Richard Stallman]

    However, the docstrings for `follow-mode' and `follow-mode-hook' are
    still wrong, because they refer to `follow-mode-hook' as if only run
    when entering follow-mode

Indeed, that should be fixed.

     (defcustom follow-mode-hook nil
    -  "Hooks to run when Follow mode is turned on."
    +  "Normal hook run by Follow mode."

"Run by Follow mode" is not correct either, because that
implies that the _mode itself_ runs the hook.

In fact, it is the function to enable or disable the mode
that runs the hook.  That function is not Follow mode.
That function is `follow-mode'.

Do you see the right way to fix it, now?

Re: follow-mode's use of hooks

[Juanma Barranquero]

On 10/9/07, Richard Stallman <rms@gnu.org> wrote:

> In fact, it is the function to enable or disable the mode
> that runs the hook.  That function is not Follow mode.
> That function is `follow-mode'.

OK.

BTW, half the docstrings of follow.el refer to "Follow Mode" and half
to "Follow mode". Not sure which one is better, but I'd love to
homogenize them...

             Juanma

Re: follow-mode's use of hooks

[Richard Stallman]

    BTW, half the docstrings of follow.el refer to "Follow Mode" and half
    to "Follow mode". Not sure which one is better, but I'd love to
    homogenize them...

Use lower case "mode".  That's the convention we use in Emacs
for mode names.

Thanks.