Invoke Activity process/project as a Web Service

[alexander81]

Hello,
I recently discovered Activity as a BPMN engine and while the documentation provides great information on how to define web service clients as part of a process, yet I could not identify whether an Activity process or project may be invoked as a web service of any kind (e.g. SOAP or REST).
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A similar concept is provided in BPEL engines, exposing a project as a web service provider (although the whole approach is more technical-wise rather than business-wise).
If the aforementioned feature is available, could you please point me to any available resources/documents?
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Thank you in advance

[alexander81]

To forum moderators: As I cannot edit (or even delete) my initial post, could you please perform the following:
1. Replace 'Activity' with 'Activiti'.
2. Edit topic title as 'Expose Activiti process/project as a Web Service'.
3. Delete this comment of mine.

Thanks for your actions

[jbarrez]

No, Activiti does not have this capability that a process itself can be exposed as a webservice.

Also, no need to make those adjustments, we're all friends here 😉

[alexander81]

Thanks Joram for your prompt response!
Therefore, to my understanding, the unique invocation method of a starting process is via a HTTP call?

[trademak]

Right, via a HTTP / REST call.

[alexander81]

Hello trademak!
Since a REST call is a feasible invocation means for a starting Activiti process, doesn't that imply that the process itself is exposed as a Web Service?

For example, let me describe the following use case:
* Client invokes Activiti via a REST call in order to start the execution of process XYZ, using POST runtime/process-instances (see: http://activiti.org/userguide/index.html#N13CE6). Input parameter "processDefinitionKey" should be XYZ.
* Activiti dispatches a REST response indicating the process instance ID that just started. Let's assume ID=7.
* Client repeatedly invokes GET history/historic-process-instances/7} (see: http://activiti.org/userguide/index.html#N152AE) in order to verify whether the process has been completed. Once "endTime" output parameter is not empty, the loop is terminated.
* Assuming that process XYZ does not contain any manual/form tasks, the Client has successfully invoked it using a Web Service approach.

I would appreciate if you could provide me with your feedback regarding the points mentioned above.
Thank you in advance!

[trademak]

What does it mean that the process itself is exposed as a web service? Activiti provides a REST API to interact with a process definition or instance based on a number of query options. This API is generic, there's no specific API available for each process definition. What would be the use case of having such a specific API?

Best regards,

[alexander81]

Hello!
I am not suggesting any changes in the way Activiti is invoked; I only commented on Joram's response.

In my initial post I asked

whether an Activiti process or project may be invoked as a web service of any kind (e.g. SOAP or REST).

According to the user manual, the existing REST API allows an Activiti process to be exposed as a Web Service, meaning there is absolutely no need for human interaction E2E (as seen in the use case I described in my previous post).