bug#26871: 25.2; Support revert-buffer for Customize buffers

bug#26871: 25.2; Support revert-buffer for Customize buffers

[Phil Sainty]

The only way I'm aware of to refresh a Customize buffer when things
have changed externally is to kill the buffer and recreate it.

It would be convenient if `revert-buffer' was supported, and bound
to "g" as usual.




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bug#26871: 25.2; Support revert-buffer for Customize buffers

[Drew Adams]

+1.

This emacs.SE question:
https://emacs.stackexchange.com/q/32714/105
shows that at least one user expected existing Customize buffers to
auto-revert.  This enhancement request will help in that direction
(not automatic, but that's OK).

bug#26871: 25.2; Support revert-buffer for Customize buffers

[Phil Sainty]

On 11/05/17 11:01, Drew Adams wrote:
> https://emacs.stackexchange.com/q/32714/105
> shows that at least one user expected existing Customize buffers to
> auto-revert.  This enhancement request will help in that direction
> (not automatic, but that's OK).

That question did indeed prompt this, but I've been meaning to raise
it for a long time.

It can be particularly confusing when the buffer exists but is not
displayed, as if you invoke the customize command in that scenario,
the behaviour *appears* to be the same as if the buffer had not
already existed, but that's not actually the case, and it might be
showing you stale data.

That's also slightly tangential to the stated feature request, but
revert-buffer support again seems like the logical first step.

bug#26871: 25.2; Support revert-buffer for Customize buffers

[Lars Ingebrigtsen]

Phil Sainty <psainty@orcon.net.nz> writes:

> The only way I'm aware of to refresh a Customize buffer when things
> have changed externally is to kill the buffer and recreate it.
>
> It would be convenient if `revert-buffer' was supported, and bound
> to "g" as usual.

Yeah, reverting in Customize buffers can be convenient, especially when
developing (and loading new stuff), so I've added this to Emacs 28.
(But it uses the global `C-x x g' binding, because the Customize buffer
is semi-editable, so it'd be confusing (and error-prone) to bind `g' to
this outside of the editable fields.)

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#26871: [External] : bug#26871: 25.2; Support revert-buffer for Customize buffers

[Drew Adams]

> > The only way I'm aware of to refresh a Customize buffer when things
> > have changed externally is to kill the buffer and recreate it.
> >
> > It would be convenient if `revert-buffer' was supported, and bound
> > to "g" as usual.
> 
> Yeah, reverting in Customize buffers can be convenient, especially when
> developing (and loading new stuff), so I've added this to Emacs 28.
> (But it uses the global `C-x x g' binding, because the Customize buffer
> is semi-editable, so it'd be confusing (and error-prone) to bind `g' to
> this outside of the editable fields.)

1. `revert-buffer' is very useful for Customize.
Thanks for adding it.


2. FWIW, I disagree that `g' should not be bound to
`revert-buffer' in Customize buffers (outside of
editable fields, obviously).

Your logic would have us also remove the bindings
of `n', `p', `q', `u', `DEL'...
`g' should be bound to `revert-buffer'.


3. A related feature is to be able to update, for
Customize, all options, faces, or both, to their
current states as set outside Customize.  IOW,
not just revert the current Customize buffer but
update Customize more generally.

My library `cus-edit+.el' offers that: commands
to tell Customize to sync its understanding with
the wider Emacs world for (1) all options, (2)
all faces, or (3) all options and faces.  Command
`customize-update-all' does #3.

You can put `customize-update-all' on an idle
timer to keep Customize synced with what happens
outside of Customize, so you can change anything
anywhere in Emacs and have Customize reflect that.

When you exit Emacs, you can be told about all
changes and asked if you want to save them.

https://www.emacswiki.org/emacs/CustomizingAndSaving#summary