Add namespaces to MgdSchema types

[bergie]

Now all MgdSchema types reside in the Midgard root namespace, so my_article becomes a my_article class in PHP, or midgard.mgdschema.my_article in Python. But we could support namespaced types, and that would also fit JCR compatibility better.

So:

<Schema xmlns:my="http://example.net/myschema/">
    <type name="my:article">

Would map as \my\article in PHP, and midgard.mgdschema.my.article in Python. JCR mapping would obviously be my:article.

[bergie]

In JCR world also properties have namespaces, but this maps a bit badly to most languages, so probably we could do something like:

<property name="my:foo">

Which would map to $object->my_foo in PHP, etc. Again, makes RDF compatibility easier.

[bergie]

Also note that namespaces used should have a valid xmlns definition in the file (the URI there doesn't need to point anywhere real, though). If they're not there, Midgard should throw an error.

On some API level Midgard should then understand that my:foo and http://example.net/myschema/foo are the same.

[piotras]

Property read and write is not that trivial due to GObject limitations. We already discussed it. Proposed MidgardCR API resolve this problem: http://www.midgard-project.org/api-docs/midgard/core/unstable/midgard3/MidgardCR/MidgardCR.RepositoryObject.html.

[bergie]

Oh, and since MgdSchemas have a default namespace, Midgard should also know that midgard_attachment and http://www.midgard-project.org/repligard/1.4/midgard_attachment are the same.