ignoring tags (was: event XML 1.1 (fix recurrances))

Gerd v. Egidy gerd.von.egidy at intra2net.com
Wed Feb 14 14:51:27 CET 2007


> > So indeed only first-level child elements of the <event> element are
> > preserved. Unknown elements at other levels are not preserved; this would
> > be quite difficult. Unknown elements inside the unhandled toplevel
> > element are not preserved either; this might be possible to add though, I
> > guess (storing a tree instead of a text node only).
> this sound like a bug to me, because it would not preserve the tag
> on toplevel anymore, would it?

Currently we have this sentence in chapter 1.2:

If a client sees a tag it does not understand, this tag must be preserved and 
saved back to the file. This allows for client specific tags. Outlook writes 
it client specific tags directly in a tnef file that is saved as an 
unreferenced attachment.

And it seems like everyone is understanding it a bit differently. I think we 
should clarify it now. I think we have the following possibilities:

a) preserve only the unknown tags on the top-level, but the unknown top-level 
tags get preserved with all their contents and attributes. 

aa) We do not add tags to lower levels anymore.

ab) The content of lower level tags is lost when the object is changed by a 
client implementing an older version of the spec.

b) preserve unknown tags on all levels.

I think aa) is not a good solution, think of the recent discussion of adding 
p.o. boxes to <address>. Adding p.o. boxes to the top-level would totally 
clutter the format of <contact>.

So I think it all boils down to ab) or b).

ab) is easy to do but makes migration and heterogeneous environments harder
b) is harder to implement on client-side

What is more important for us?

Kind regards,


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