elisp: Alias Menu Items
21.17.1.4 Alias Menu Items
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Sometimes it is useful to make menu items that use the same command but
with different enable conditions. The best way to do this in Emacs now
is with extended menu items; before that feature existed, it could be
done by defining alias commands and using them in menu items. Here’s an
example that makes two aliases for ‘read-only-mode’ and gives them
different enable conditions:
(defalias 'make-read-only 'read-only-mode)
(put 'make-read-only 'menu-enable '(not buffer-read-only))
(defalias 'make-writable 'read-only-mode)
(put 'make-writable 'menu-enable 'buffer-read-only)
When using aliases in menus, often it is useful to display the
equivalent key bindings for the real command name, not the aliases
(which typically don’t have any key bindings except for the menu
itself). To request this, give the alias symbol a non-‘nil’
‘menu-alias’ property. Thus,
(put 'make-read-only 'menu-alias t)
(put 'make-writable 'menu-alias t)
causes menu items for ‘make-read-only’ and ‘make-writable’ to show the
keyboard bindings for ‘read-only-mode’.
Info Catalog
elisp: Menu Separators
elisp: Defining Menus