Information Technology Reference
In-Depth Information
previous algorithms and discerns two cases. If
C
is an atomic service, then the appropri-
ate parts of the OWL-S process description are created that describe the service along
with its inputs and outputs. Specifically, for every input of the atomic service, an input
element is created by calling the
InputElement
function of the OWL-S API. All the
input elements are gathered in a list which is then set as the value of the
hasInput
field
of the OWL-S process description. The same steps are followed for the creation of the
output list which is the value of the
hasOutput
field in the description.
Algorithm 4 (OWLSProcess):
Creates the OWL-S process
description
Inputs
: C = f(a
0
,a
1
,..a
n
)
Output
: The OWL-S process description of C
if f = atomic then
A = OWLSAPI.AtomicProcessElement
LI = LO = {}
for each p
i
∈
prec(a
0
)
k
i
= OWLSAPI.InputElement(p
i
)
LI = LI + {k
i
}
OWLSAPI.hasInput(LI)
for each o
i
∈
add(a
0
)
m
i
= OWLSAPI.OutputElement(o
i
)
LO = LO + {m
i
}
OWLSAPI.hasOutput(LO)
PE = OWLSAPI.PerformElement
return PE.add(A)
else
CC = OWLSAPI.ControlContruct(f)
CC.add(CLO(C))
return CC
If
C
is not just an atomic service, but instead a composite one, then the appropriate
control construct element is created (
seq
,
split
,
split-join
) according to
f
and the algo-
rithm
CLO
is called to create the list of the services that takes part in this element.
Then, this list is added to the control construct element and this is the object that the
OWLSProcess
algorithm returns. In fact, this object contains all the information about
the OWL-S process description of
C
.
Algorithm 5 (CLO):
Creates the List Object containing
the atomic services of the composite one
Inputs
: C = f(a
0
,a
1
,..a
n
)
Output
: LO: the List Object
if n = 0 then
return null
LO = OWLSAPI.ListObjectElement
LO.First = OWLSProcess(a
0
)
LO.Rest = CLO(f(a
1
,a
2
,…,a
n
))
return LO
The algorithm
CLO
has as input a composite web service functional representation,
which is in essence a functional representation with OWL-S control construct
connecting the participants services, and creates using the OWL-S API a
List Object
