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adjust the related RfC "SystematicMetadata"

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There is a long-standing RfC which basically describes the
same idea on a much wider, conceptual scope. Indeed I consider
this approach used here for solving the problem with GUI uptades
also as a proof of concept, to be expanded to a much wider scope
in case it works out well.

The new insight here is, that, by transferring a diff in pull mode,
we can circumvent the architectural problems with typing, which
showed up quite clearly in earlier design studies towards this
concept. The change from push to pull is by far not so fundamental
as it looks, since the sender still may initiate the exchange
by sending a message offering the diff iterator for the receiver
to pull. This way, we get a handshake and still sustain the
crucial part, which is to decouple the data representation
and give the receiver full control over the interpretation
of the exchanged data.
This commit is contained in:
Fischlurch 2015-03-22 01:37:16 +01:00
parent b051845835
commit f90e9c7bbd
1 changed files with 7 additions and 5 deletions
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12
doc/devel/rfc/SystematicMetadata.txt
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@ -33,11 +33,13 @@ to span the whole virtual model, and thus there never needs to be an universal
model data structure definition. Data structure becomes implementation detail.
Parts of the system talk to each other by _describing_ some subtree of metadata.
This description is _always pushed:_ the receiver implements an API allowing the
sender to navigate to some path-like scope and populate it with values, similar
to populating a filesystem. It is up to the receiver to assemble these information
into a suitable representation. Some receiver might invoke an object factory, while
another serialises data into an external textual or binary representation.
This description is transferred _in the form of a tree diff:_ the receiver pulls
a sequence of diff verbs from a diff iterator, and interpreting these verbs will
walk him down and expand the tree in question. Sub-scopes are ``opened'' and
populated, similar to populating a filesystem. It is up to the receiver to
assemble these information into a suitable representation. Some receiver
might invoke an object factory, while another serialises data into an
external textual or binary representation.
Abstract Metadata Model