Yesterday I added a new feature that lets you conveniently access items
contained in parcels without needing to directly use repository paths,
UUIDs, or other mechanisms. It works similarly to an "xmlns" declaration
in parcel.xml, except you use it in Python code.
I originally wrote it to experiment with ways to speed up the parcel
loader, but from discussion during some of today's meetings I gather that
other people are interested in knowing about it.
The feature is ``schema.ns``, and you can use it something like this:
from application import schema
...
# code that needs access to items in the "osaf.current" parcel
current = schema.ns('osaf.current', repoView)
current_contact = current.Contact.item
Basically, it makes the named parcel accessible via dotted attribute
access, giving you either the contents of the module (classes, methods,
etc.), or the contents of the parcel (i.e. items). It is considerably
faster than access via absolute repository paths such as
"//parcels/osaf/current/Contact".
In any case, we want to stop using paths as a primary access method, so
that we can get rid of kludges like __parcel__, and so that developers only
have to learn and remember one kind of "address" for parcel items. Over
time, we'll hopefully be able to remove all parcel path dependencies from
the Chandler code base, which will also be helpful in flattening the
currently very deep package hierarchy.
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