Proposal: slight change to the XML dump format - Wikitech-l

23 Oct 2014

tl;dr:

In the xml dumps, I want to change
<text> <sha1> <model> <format>
to
<model> <format> <text> <sha1>

However, this is a breaking change to our XML schema.
See https://bugzilla.wikimedia.org/show_bug.cgi?id=72417

Background:

While trying to fix bug 72361, I ran into an issue with our current XML dump format:

The <model> and <format> tags are placed *after* the <text> tag.
This means that we don't know how to handle the text when we process XML events
in a stream - we'd have to buffer the text, wait until we know model and format,
and then process it. A pain.

The current order has no deeper meaning - it is, indeed, my own fault: i didn't
think this through when adding these tags. I propose to change the order of the
tags now, to make stream processing easier.

That would technically be a breaking change to the dump format, incompatible
with <https://www.mediawiki.org/xml/export-0.8.xsd> and export-0.9.xsd. I doubt
however that any consumers rely on the current placement of <model> and
<format>, as it is extremely inconvenient (compare bug 72361), but you never know.

I propose to release a new XSD version 0.10 with the order changed, and mention
it in the release notes. Should be fine.

Any objections?

-- daniel