Original Publication Date: 2004-Oct-11
Included in the Prior Art Database: 2004-Oct-11
Business Process Execution Language for Web Services (BPEL4WS) is an evolving OASIS standard for defining business processes that orchestrate the execution of Web Services. It is suggested that query activities are being added to the language. The purpose of query activities is to obtain process instance relevant information.
Query Activities Query ActivitiesQuery Activities Query Activities
Business Process Execution Language for Web Services (BPEL4WS) is an evolving OASIS standard for defining business processes that orchestrate the execution of Web Services. Typical activities are invoke for invoking a Web Service and receive to receive the answer of an invoked Web Service . BPEL4WS currently does not support queries that obtain information about a running process instance, such as the time the process instance has started or the actual state of the process instance . Those queries could be used internally in expressions, for example, in transition conditions or externally to query the state of a process instance. It is suggested to provide this information via query activities.
A query activity conceptually consists of a query that extracts information for the process instance and the data that is being extracted . In its simplest incarnation, the query activity retrieves a set of re-defined data and makes it available in an appropriate BPEL variable. Such an activity would look like:
If executed, the query would store the data in the specified BPEL variable . The retrieved data can now be used as normal, for example as values in transition conditions.The query could also be included in an event handler. This would allow to receive a request from the outside, perform the appropriate query, and send the output back via an ap...