This post originated from an RSS feed registered with Java Buzz
by Brian McCallister.
Original Post: Ruby Orchestration Language Fun
Feed Title: Waste of Time
Feed URL: http://kasparov.skife.org/blog/index.rss
Feed Description: A simple waste of time and weblog experiment
After the Silicon Valley Ruby Conference I wanted
to hack some at a declarative language for web service
orchestration. Tests pass, but the web service bindings
don't exist yet =( Right now it can be used as a nice
declarative process for... er, ruby?
class TestProcess < Test::Unit::TestCase
def test_example
p = Processor::process :wombats do
receive :message
forward :message, :to => :provisioning,
:save_reply => :provision_response
forward :message, :to => :payroll
if_test( proc { provision_response =~ /example/ } ) do
transform :message, :with => :some_transformer,
:save_in => :transformed_message
forward :transformed_message, :to => :server_group
end
forward :provision_response, :to => :helpdesk
end
The rest of the test case just mocks out the services
needed and tests that the things works. Not as exciting
but here it is for completeness =)
p.services[:provisioning] = lambda do |process, msg|
@provision_msg = msg
assert process.expecting_response?
"address@example.com"
end
p.services[:payroll] = lambda do |process, msg|
@payroll_msg = msg
end
p.services[:server_group] = lambda do |process, msg|
@server_group_msg = msg
end
p.services[:helpdesk] = lambda do |process, msg|
process.suspend
end
msg = OpenStruct.new
p.start msg
assert_equal @provision_msg, msg
assert_equal @payroll_msg, msg
assert_equal @server_group_msg, "address@example.com"
assert_equal p.transformed_msg, "address@example.com"
assert p.suspended?
p.resume "back from helpdesk"
assert p.completed?
end
end
For the most part I am kind of happy with it. The nasty
wart of
annoys me. It's needed to lazily evaluate the construct, using
a real if there evaluates it at the wrong time. Astute
code readers will also notice I am not testing the transform. Haven't
done that yet -- will probably remove it as a first class concept
if I do anything more with the code, a transform is just a local
service, and services are all wrapped in ruby methods, so instead
of importing the service, just provide the transform and voila, your
toast is burnt.
Wish ruby continuations were migratable/serializable.
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