Re: Problems with whole buffer Custom functions.

[Juri Linkov]

> I assume you mean that there would be a separate M-n/M-p history for
> each value (editable field).

I meant a history mechanism like is used in modern GUI applications,
e.g. in Firefox typing M-down in an editable field opens a list of
values previously entered into the same field.  There is also Emacs-like
completion that filters out values based on the contents of the field.

> What would be the extent (limit) of the proposed history list(s)? Would
> the limit be the current Emacs session? the current access to Customize
> for that field? Or would the histories be persistent (e.g. via
> savehist.el)?

Adding a new history variable with a list (or alist with one sublist per
option/field or per widget class) of previously entered values would
automatically allow saving it with savehist.el or desktop.el.

> What would constitute an entry in such a history list: would it be each
> individual edit (a la undo) or each value that the user sets or saves
> (via Set for Current Session or Save...)?

I think preserving each value that the user sets or saves is more useful
than preserving mini changes undoable with the ordinary undo.  This would
work exactly like history lists work in the minibuffer: in the minibuffer
history list gets updated after exiting with RET, in editable fields this
could be done after activating the field.

-- 
Juri Linkov
http://www.jurta.org/emacs/