Config protocol -- when do config values reset?

[Gerry Duprey <gerry@xxxxxxxxxxx>]

Howdy,

I'm just about done implementing xPL in java and will be releasing this
soon.
I'm finishing the configuration handling and had a questions about what a
device should do when receiving a config.response message.  Specifically,
when
should the device clear it's own configuration values.

For example, by previous conversations here, it appears that if the device
has
groups or filters, they should be reset as part of the processing of the
config.response message.  In short, if a device has existing filters and a
config.response is received, those filters should be dumped -- even if if
there is no filter= in the message body.  Same for groups.

When dealing with device specific values, especially multiple values (like
filter and group where than can be >1 value associated with a single
name),
there is a question as to when the device should clear those values when
processing the config.response.  The two ways I can imagine are:

1) just like filters and groups, as soon as the config.response is
received,
all configurable/reconfigurable values should be cleared regardless of the
content of the message.

2) When the first instance/reference to a config values name is encountered
while processing the message body. Only at that point would all values
matching that config name be cleared.

It would seem to me that #1 should be the case as that matches the group=
and
filter= tag, but I'm not seeing it specifically spelled out in the xPL
docs.

The benefit to #1 is it's the only way to "erase" an obsolete
configuration
value.  If #2 were the case, you'd have to know of the obsolete config
value
to include it, at least once, to cause the old, obsolete config values to
be
dumped.

By way of example, please consider this config.response

...
config.response
{
color=red
color=blue
color=green
}

If this is the first response, after I'm done I have a configuration item
called "color" with three values in it.  If later I receive this

...
config.response
{
meal=taco
}

on the same device, should I have cleared all the values for the
"color"
element previously configured? (the #1 scenario) or left hem in tact since
there is no color= tab (the #2 scenario)?

Thanks!

Gerry

--
Gerry Duprey
Ann Arbor, MI 48103
http://www.cdp1802.org