1. 1 BP-64: OASIS BPEL4Pople TC BP-64: A need for a "GetUI” for a Task Yoichi Takayama MELCOE (Macquarie e-Learning Centre of Excellence) Macquarie University Sydney, Australia

2. 2 BP-64: OASIS BPEL4Pople TC Issue B4P remoteTask defines a partnerLink, operation and responseOperation (for async request) to call a remote Web Service, that implements the WS- HumanTask. B4P and WS-HT docs also define WS-HT Protocol for WS-C to control the life cycle of the Task. It, however, does not define how the remote Web Service can supply the remote Task implementation (UI) to the end user.

3. 3 BP-64: OASIS BPEL4Pople TC Human Task Constellations

4. 4 BP-64: OASIS BPEL4Pople TC Assumption The remoteTask supplies a Task UI to a local user to do the Task on the Task Client in the local system. A remote Web Service that requires only a remote user input does not have to supply a UI to the local system. Such a service can be defined as a regular BPEL invoke activity (synchronous or asynchronous).

5. 5 BP-64: OASIS BPEL4Pople TC Reasoning B4P defines inline Task and local Task. It is presumed that these use proprietary mechanisms for Task UIs, e.g. supplying a simple form-based UIs or Web applications to the end users. So, this is out-of-scope. A remoteTask, which uses a regular Web Service interface, then presumably also supplies a UI to the end user. It must define a standard mechanism to invoke the end user interface (Task UI).

6. 6 BP-64: OASIS BPEL4Pople TC Reasoning 2 A remote Human Task (HT), implemented as a remote Web Service, is different from normal Web Services. Normal Web Services, synchronous or asynchronous, do not supply human interfaces (UIs) to the callers. In case of a remote HT, it must supply a UI. User communications over the UI channel must be also supported.

7. 7 BP-64: OASIS BPEL4Pople TC Current B4P & WS-HT Process instance (definition) Task List Task Processor Task Instance remoteTask (Web Service) request response WS-C register WS-C register response Task ?

8. 8 BP-64: OASIS BPEL4Pople TC Problem How can the end user get the remote Task UI? The UML sequential diagram would show that the progress just stalls when the Task Instance on the Task Processor sends the WS-C register response to the remote Task as Web Service.

9. 9 BP-64: OASIS BPEL4Pople TC Problem 2 The WS-HT proposal has no description whatsoever how the remote Task UI is obtained and how this starts the local Task UI client to present it to the end user. This cannot be left to some proprietary mechanisms like inline- or local Tasks, because then there will be no interoperability.

10. 10 BP-64: OASIS BPEL4Pople TC One solution Process instance (definition) Task List Task Processor Task Instance remoteTask (Web Service) request response WS-C register WS-C register response getUI Task do Task

11. 11 BP-64: OASIS BPEL4Pople TC Proposal Move the issue from “New” to “Current” and investigate what the best option is for us. Suggest the way it can be done. –How to get the remote UI information. –The caller passes the UI information to an appropriate Task Client (if such is available for the B4P system) which handles the UI and the communications. (This part is out of scope, i.e. it is only an indication of how-to but with no details). –When it finishes, it signals the Task, which then returns the “response” for the original Task request. (This part is out of scope).