Re: [xml] Ordering of TAGS and data

[Stefan Seefeld <seefeld sympatico ca>]

Paul Robert Hayes wrote:

> When libxml reads the tags and attributes, it
> will place them in the tree in the order they occurred in the original XML
> data file.  The data within each <first> </first> should remain as placed in
> the XML file.

No ! That's only true for elements (<element>), but *not* for
attributes. There is no guarantee being made about any ordering of
attributes, Tomorrow's libxml2 release could change the order of the
attributes in its internal representation. You *must not* rely on any
ordering. If you have such a requirement, it's a good sign that you
should use elements instead.

> What I am hearing is that I do not need to have the "seq" attribute below on
> each data element because the second example should be parse in file order
> and thus can be added to a linked list in order.  The <data> would always be
> listed in first to last order in our examples.

That's right.

> On the other hand, if we wanted to allow the <data> elements to be ordered
> but randomly entered into the data file, then the "seq" attribute would be
> required which could be parsed from libxml as the <data> attribute and then
> assigned to the list in the correct order.

yes, any semantics you add above the XML level is up to you.

Regards,
                Stefan