In planning for a generalized "directory" component (see comment in ), it seems inevitable we will have to somehow infer data types other than strings in page metadata.
We already interpret mummy:order as integer, but only after the fact, dynamically, when reading it. In the future this can be changed by creating type rules for the mummy: ontology.
We need to decide on a more general facility for specifying a "publication date". The best approach seems to be to infer the type of properties with no particular namespace indicated (i.e. in the URF ad-hoc namespace), using the pattern xxxOn to indicate a local date (i.e. _YYYY-MM-DD_). Ontology-based type definition for other namespaces is being relegated to GUISE-132.
There are two possible approaches. One is perhaps cleaner and more elegant: move the publishedOn property from to the mummy namespace, i.e. mummy:publishedOn. Then we would have complete freedom to parse values as we like, preferably (in the future) based upon some ontology definition. Then even mummy:order from could automatically be parsed as an integer upon read, rather than dynamically upon use as we do now.
The other approach would be to indicate some convention for property names with no special namespace, so that xxxOn (xxx-on in HTML) would automatically be parsed as a local date (or local year-month or local year). (This technique could be complementary; we could still have this facility even if we decide to use mummy:publishedOn.
The downside to putting this in the mummy: namespace is that this property would not wind up in the final page metadata (although it would be stored in the site description). Having a publishedOn property in page metadata is useful, and already in the property shows up nicely in the generated pages as e.g. <meta name="published-on" content="2001-02-03" />.
The xxxOn convention is looking very compelling, especially since dates are ubiquitous and so important. We could stress that if other special interpretation is needed, users can place properties in custom namespaces with ontologies defined somewhere.