Generalise the ability to look up a dynamic user interface item by
index or by shortcut key, to allow for reuse of this code for
interactive forms.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
We currently have an abstract model of a dynamic menu as a list of
items, each of which has a name, a description, and assorted metadata
such as a shortcut key. The "menu" and "item" commands construct
representations in this abstract model, and the "choose" command then
presents the items as a single-choice menu, with the selected item's
name used as the output value.
This same abstraction may be used to model a dynamic form as a list of
editable items, each of which has a corresponding setting name, an
optional description label, and assorted metadata such as a shortcut
key. By defining a "form" command as an alias for the "menu" command,
we could construct and present forms using commands such as:
#!ipxe
form Login to ${url}
item username Username or email address
item --secret password Password
present
or
#!ipxe
form Configure IPv4 networking for ${netX/ifname}
item netX/ip IPv4 address
item netX/netmask Subnet mask
item netX/gateway Gateway address
item netX/dns DNS server address
present
Reusing the same abstract model for both menus and forms allows us to
minimise the increase in code size, since the implementation of the
"form" and "item" commands is essentially zero-cost.
Rename everything within the abstract data model from "menu" to
"dynamic user interface" to reflect this generalisation.
Signed-off-by: Michael Brown <mcb30@ipxe.org>