topic Re: Activiti Workflow and Project Architecture in Alfresco Archive

Activiti Workflow and Project Architecture

fritz128 — Fri, 06 Sep 2013 07:24:57 GMT

I start to integrate Activiti in my application, and I faced architecture problems.My bussiness logic looks like: //this handler proceed ALL logic, and call needed activiti to do the final actions public void handle(org.eclipse.jetty.websocket.api.Session clientSession) { //I. Create and Save t

Re: Activiti Workflow and Project Architecture

trademak — Fri, 06 Sep 2013 08:16:29 GMT

Maybe you can use a ThreadLocal to store the session and retrieve it from a service task. But that only works if you don't have asynchronous parts in your process.

Best regards,

Re: Activiti Workflow and Project Architecture

jbarrez — Fri, 06 Sep 2013 08:19:56 GMT

The right architecture for this case is *NOT* to serialize something like a session, that's always a bad idea.
The right architecture would inject the current session into a JavaDelegate of Activiti, which is managed by a container such as Spring or CDI.

Re: Activiti Workflow and Project Architecture

jbarrez — Fri, 06 Sep 2013 08:20:41 GMT

(and they will probably use thread local behind the scenes, as Tijs suggested)

Re: Activiti Workflow and Project Architecture

fritz128 — Fri, 06 Sep 2013 12:27:29 GMT

First of all, thank you for reply!

I get you the more detail disclosure of my subprocess, and try to explain why Injection & ThreadLocal seems not appropriate in my case.

My workflow:
I have some global process, for example, car lottery. This process starts when manager push "Start Lottery" button. He can start many loterries simultaneously.
To participate in this lottery user should go throught several stages of registration, attend on lottery, take a price (big or small, little price gives to all participants), and so on. So this task need to be moved to separate subprocess.
Workflow diagram:
[img=http://s2.postimg.org/ioq6jynp1/Process.jpg]

Problems:
I don't say that that are bad approaches, I only want to know if it is possible to solve the problems below
Why not inject:
1. As I understand, serviceTask creates only once for all subprocesses. If yes, it is not a good approach in my case, beacause I want to launch subprocess each time for different client (ass a result, each time for different session).
Why not thread local
2. Thread local is a good thing. But as I understand I should intialize my ThreadLocal session in the first task of the subprocess. This means that I should retrieve session from some getSession() method. But again, what about remote machine & serialization?

Re: Activiti Workflow and Project Architecture

jbarrez — Thu, 12 Sep 2013 12:14:23 GMT

1. In the regular Activiti way, yes. However, when integrating with a dependency container things change a bit. If you reference a bean that has a certain scope (eg session-scoped) in that container, the actual service task is not static for all processes. I didn't say that in my original post, correct, it shouln't be the session that it injected, rather the bean acting as the service task.

2. No, the session should be managed by a container and let the container manage the storage and all that. I was just saying that typically, frameworks such as Spring use thread local to do exactly that.

Re: Activiti Workflow and Project Architecture

dmifs — Mon, 10 Mar 2014 09:07:53 GMT

Hi this is basically the same problem that I am facing. I want to start an activiti process and then send a message through a web socket when some event occurs in activiti ( such as end of process). I still cannot figure out how would I be able to inject the web socket sessions in a Java Delegate class or an ExecutionListener class (such as end of process). An example would help a lot maybe using CDI.

thanks

Re: Activiti Workflow and Project Architecture

frederikherema1 — Mon, 10 Mar 2014 09:38:49 GMT

Using CDI in a tasklistener is quite easy. Just inject everything you want in the TaskListener implementations. Next, configure activiti to use CDI (see userguide) and finally in your process, you reference the CDI-bean from within the task-listener, using activiti:delegateExpression="myAwsomeBean". Hope this helps…