On Aug 1, 2008, at 9:08 AM, Ivan Trajkovic wrote:
on a side note, it would be cool if the interface definition for the
processes was abstracted into its own layer, so that other IDL's
(besides
WSDL) could be used (WADL, Google protocol buffers - although Im
still not
that familiar with GPB's as they might be only a simple data message
definitonl language[perhaps can be hacked into definiting method
signatures
as well])... either way, it would seem powerful if ODE was capable to
accomodate other IDL's, its use would increase drastically... I
understand
this probably a non-trivial amount of work.
Other IDLs is a big deal, depending on how you look at it, since the
combination of XML, WSDL, and XPath (1.0 or 2.0) is deeply ingrained
in the BPEL language. (File that under "it seemed like a good idea at
the time"...) It's certainly conceivable that people would be
interested in using something like Java for the IDL with POJOs, no IDL
with JSON/Javascript, etc. The good thing about the WSDL/XML/XPath
stack is that it's friendly with the philosophies of the engine and
the design of BPEL, and it's purely a question of effort and
inclination for someone to have a version of ODE that would support
their chosen combination of IDL, expression language, and message
format so long as the overall flavor of the implementation didn't
change too much.
Now, that said, some of this is purely a matter of the level of
indirection in your thinking, and this is why the integration layer
(IL) that Matthieu pointed you at is probably the right place to
start. For the engine to use XML internally along with all of the
usual trappings (WSDL, XSLT, XPath, etc.), you could feed it about
anything — JSON, EDI of various flavors, a binary wire format, etc. —
which would be dealt with as XML within the confines of the engine and
converted to and from XML by the IL.
Given that you seen to have a taste for the wind in your hair and bugs
in your teeth (a good thing!), you should also take a look at the
JaCOb actor layer that underlies the ODE BPEL implementation.
-- Paul
