topic Re: What 'taskService.claim' means? in Alfresco Archive

What 'taskService.claim' means?

hamed — Sat, 05 Nov 2011 07:04:33 GMT

Hicould you please explain me the concept of claim i have worked with jbpm 3 for months and i haven't seen something like this! Regards

Re: What 'taskService.claim' means?

hamed — Tue, 08 Nov 2011 06:44:38 GMT

is it difficult for you to explain that? or my question is so silly?

Re: What 'taskService.claim' means?

partizano — Tue, 08 Nov 2011 08:18:11 GMT

Hi,

Task not always has assigned user. So "Claim" means "set assigned user".

Re: What 'taskService.claim' means?

ronald_van_kuij — Tue, 08 Nov 2011 16:22:07 GMT

no, GET assigned tou yourself. If assiging to someone else it is setAssigninee (but this is all in the docs)

Re: What 'taskService.claim' means?

partizano — Wed, 09 Nov 2011 09:42:47 GMT

no, GET assigned tou yourself.

The name of the topic - "What "taskService.claim" means?" So Hamed is intrested in org.activiti.engine.TaskService.claim(String taskId, String userId) method. And as it says in the docs - "Claim responsibility for a task: the given user is made assignee for the task.".

Re: What 'taskService.claim' means?

hamed — Wed, 09 Nov 2011 16:41:31 GMT

Thank Alexander
i'v read that in doc, but i have a question related to my previous question : when do we use Claim? when we assign the task to the group that has users, which one of them should claim that?!
And if i want to assign the task to some group that all users in it should complete the task in order to signal the task to next step, what should i do??!

Re: What 'taskService.claim' means?

partizano — Thu, 10 Nov 2011 05:51:03 GMT

when do we use Claim?

When the user claim the task it means that the user begin to work on the task.

when we assign the task to the group that has users, which one of them should claim that?!

There is no assigned group in activiti, there is candidate group.

And if i want to assign the task to some group that all users in it should complete the task in order to signal the task to next step, what should i do??!

You should set candidate group for the task, and then user which wants to complete the task should at first run "claim" operation, then "complete"

Re: What 'taskService.claim' means?

heymjo — Thu, 10 Nov 2011 09:10:57 GMT

Also, the API difference between claim() and assign() is that claim() will throw an exception if the task has already been claimed by someone else. That is quite a nice feature, assuming that it works well with regards to concurrency etc.

Only thing is that it could throw a better exception rather than the standard ActivitiException, created an issue for this http://jira.codehaus.org/browse/ACT-991.

Re: What 'taskService.claim' means?

hamed — Thu, 10 Nov 2011 16:11:35 GMT

My thanks to all of you for your help.

Re: What 'taskService.claim' means?

lpavone — Fri, 16 Nov 2012 14:05:01 GMT

Hi all,
I want to reopen the discussion.
I have a doubt about how to work claim() and setAssignee() method respect to concurrency.
If I use either the engine works well in case that many users claims the task at the same time??
Or I need to check the concurrency ??

thanks!

Re: What 'taskService.claim' means?

frederikherema1 — Fri, 16 Nov 2012 14:12:53 GMT

setAssignee() and claim() is the same, internally…

When a task is claimed concurrently by 2 threads, one of the calling threads will get an ActivitiOptimisticLockException when calling claim() or setAssignee().