RE: Compositions Types:Static and Dynamic

Thank you all for the answers...
Answering your last question Xuan :
"How can you know by reading the WSDL document which other service(s) would be required, and what are the input/output for the other service(s)?" 

In my opinion only using WSDL you cannot know what services could be required, because many web services that do different tasks can have the same input/output. It is because that I use IOPE to know which service comes first and which one comes after. And using preconditions I can know which service is a prerequisite. 

Best regards, 
Daniela  

-----Message d'origine-----
De : Shi, Xuan [mailto:xshi@GEO.WVU.edu] 
Envoyé : vendredi 14 avril 2006 18:25
À : Daniela CLARO; ''public-sws-ig@w3.org ' '
Cc : Shi, Xuan
Objet : RE: Compositions Types:Static and Dynamic
Importance : Haute

By the way, ESRI's address geocoding Web service is just such a typical and good example for your kind attention since the geocoding service (s1) depends on the outcome of another service (s2) in order to be executed.

How can you know by reading the WSDL document which other service(s) would be required, and what are the input/output for the other service(s)?

-----Original Message-----
From: Shi, Xuan
To: 'Daniela CLARO '; 'public-sws-ig@w3.org '
Cc: Shi, Xuan
Sent: 4/14/06 12:10 PM
Subject: RE: Compositions Types:Static and Dynamic

A good way for discussion is to use living Web services to demonstrate the ideas about static or dynamic service composition. Here is a typical example for reference:

Do you want to get a 1 or 2 meter resolution arieal photo of your home place? You can get the photo by aggregating the following living Web
services:

1. ESRI's address geocoding Web service that helps you to get the latitude and longitude of your home address. Service URL is:

http://www.arcwebservices.com/services/v2006/AddressFinder.wsdl

2. Microsoft's TerraService can give you arieal photos or satellite images with resolution from 1 m to 2000 km. Service URL is:

http://terraservice.net/TerraService2.asmx?WSDL

Using .NET as an example, for static invocation, programmers has to "Add Web Reference" first to get a service stub, write OOP program based on the stub and invoke the service.

For dynamic invocation, without adding any Web references, programmers has to create a new wsdlService class that has a function InvokeWebService(url, namespace, ......) which returns an object as the output.

Given the example of AddressFinder Web service, (I am afraid you cannot figure out how to invoke this service by just reading this WSDL document, even though you may wish to add semantic annotations into it), the object returned from invocation is a GeocodeInfo object, which contains "candidates" that has an array of GeocodeCandidate. Each GeocodeCandidate has a point class that has x, y coordinates and information about the coordinate system. 

When you get x, y values through your dynamic composition and invocation process, then you can use them in TerraService to retrieve the arieal photos you want.

If anyone can tell us how to use OWL-S, WSMO, WSDL-S or something else to implement a dynamic composition and invocation to retrieve arieal photos of your home address from ArcWeb service and TerraService, then we can see the great achievement in this field. Otherwise, we have to find some other ways to do this job.

Best wishes,

Xuan

-----Original Message-----
From: Daniela CLARO
To: public-sws-ig@w3.org
Sent: 4/12/06 4:03 AM
Subject: Compositions Types:Static and Dynamic


Hi all,
 I want to hear from you about composition types. Actually, I classified the composition of sws in two categories: static compositions and dynamic compositions. 
>From static composition I mean the compositions that know iin advance
all services that will belong to the composition, for example, the use of workflows, that we decide before which services will participate to the compostion. Do you have other examples from static compositions? 

About dynamic composition, it is the use of dynamic workflow, the use of planning to compose, the use of graphs. I mean that we don't know in advance which services will participate to the composition. Moreover, if I have a service s1 that need another service s2 in order to be executed, so the dynamic composition should find this other service s2 and put s2 in the composition. Isn't that? Do you have other examples of dynamic compositions? 

So I want to hear from you what do you think about this classification and examples of static and dynamic compositions. 

Thanks in advance,
Daniela CLARO

Received on Tuesday, 18 April 2006 07:53:48 UTC