UseCase: AccessWebService

PrimaryActor:

Astronomer

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EndResult:

An astronomer with appropriate permissions can access web services as a source for a program or model. A web service is a program provided by someone else with input and output parameters strictly defined by WSDL.

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OtherActors:

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PreConditions:

This use case begins at the Run Program Façade inside the Determine Program use case. 'Web Service' has been selected as the program source.

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FlowOfEvents:

1. The Run Program Façade accesses the Web Service Façade.

2. User can contact a web service directly (via command line, text box, pull down menu, etc) or search for an appropriate service from an astrogrid web service list.

3. Use case proceeds to NegotiateAccessToResource.

4a. If web service is successfully contacted:

• Service returns a list of input and output parameters conforming to WSDL standards.

• Web Service Façade returns this information to the Run Program Façade

• Use case proceeds as Determine Program.

4b. If web service is not accessible to user:

• User receives 'web service unavailable' error message

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PostCondition:

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BasicAssumptions:

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AlternativeFlows:

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Discussion:

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Links to ScienceProblems:

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KeyReferences:

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Please see the seqence diagram for this case.

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GoodStyle: Please add comments below. This area should be used for refinement of the above document. If you want to ask questions or start a dialogue with the author, please use (or create) a topic in the Use Cases Forum.
Author: Once the refinements here and comments in the forum die down, perhaps you could rewrite the problem, incorporating the comments and refinements.

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-- ElizabethAuden - 17 Jun 2002