Schemaware for PEAW 0.2

Here is draft schemaware for snapshot 0.2 of PEAW (Pie/Echo/Atom/Whatever).

This is quite a lot better than the 0.1 cut. I took account of smart things that were said by Norm Walsh and Jeni Tennison.

One real improvement is that all the elements in <feed> and <entry> are nailed-down in fixed order, for three reasons:

1. Life is easier for quickie script writers.

2. It is possible to construct a slightly-less-unreadable XSD.

3. There doesn’t seem to be a downside.

Aside from that, the schema is very close to the snapshot spec and also more idiomatic (I’m starting to get the hang of this RelaxNG stuff).

RelaxNG Again · Once again, this is written in the RelaxNG Compact Syntax. Here’s a strong claim: this is the best syntax currently available for writing schemas for XML languages. If you’re writing schemas, and you haven’t yet taken a good look at RNG, please stop now and do so. You’ll be doing yourself a favor.

Check out that schema, there are three things in there that seem pretty magical to me that were just no trouble at all to write down:

• The way the <content> element handles the multipart/related situation (mind you, I think this is an unnecessary innovation that should be stricken from PEAW, but the schema is nifty).

• Specifying that the content of <content> can contain arbitrary markup that has to be in a namespace but can’t be in the PEAW namespace.

• Dispatching to three very different content encodings inside <content> based on the mode= attribute.

PEAW · I think it’s about ready to go, most of my gripes about the 0.1 snapshot have been addressed. I’d still like to dump the multipart/related bit, and I don’t think the way to point at a web address should be labeled Universal Republic of Love (how about <web> or <www> or <uri>), and the <generator> element has its content and attribute backwards, but none of these are showstoppers.

Oh yes, and please bring xml:base back, it’s not rocket science.

It’s getting to be about time to declare victory and turn to the software. Accordingly, ongoing now has a PEAW 0.2 syndication feed, which is valid per this schema and per the validator.