A uWDL handler for context-aware workflow services in ubiquitous computing environments

To develop context-aware workflow services in ubiquitous computing environments, a service developer must describe and recognize context information as transition constraints. uWDL (ubiquitous Workflow Description Language) [I] is a workflow language that describes the situation information of ubiquitous environments as a rule-based service transition condition. In this paper, we suggest a uWDL handier that supports workflow's service transition to be aware of user's condition information. The uWDL handler consists of a uWDL parser and a uWDL context mapper. The uWDL parser represents contexts described in the scenario with sub-trees of a DIAST (Document Instance Abstract Syntax Tree) as a result of the parsing. To derive the right transition of workflow services, the uWDL context mapper compares contexts described in subtrees of DIAST with a user's situation information generated from ubiquitous environments by using a context comparison algorithm. Therefore, the uWDL handler will be used in developing context-aware workflow applications that can change the flow of a service scenario according to the user's situation information in the ubiquitous computing environment.