topic Re: unknown type of task candidate in Alfresco Archive

unknown type of task candidate

christoph_retti — Tue, 23 Oct 2012 03:45:33 GMT

Hi, is there a way to set a task's candidates without specifying that the candidates are users or groups?I would like to have a user task where the user specifies the possible candidates for the next task from a list and it wouldbe very convenient if I could just set a task variable ${assignee} to s

Re: unknown type of task candidate

ronald_van_kuij — Tue, 23 Oct 2012 05:56:56 GMT

These are just strings… What about name clashes then?

Re: unknown type of task candidate

christoph_retti — Tue, 23 Oct 2012 08:29:32 GMT

Hi Ronald, I guess they could be handled exactly the same as documented in

If no specifics are given whether the given text string is a user or group, the engine defaults to group. So the following would be the same as when group(accountancy) was declared.
<formalExpression>accountancy</formalExpression>

(taken by http://www.activiti.org/userguide/index.html#10minutetutorial). For me its perfectly ok if you prefer groups over users and I think normally you don't have name clashes with groups and users.

regards, chris

Re: unknown type of task candidate

frederikherema1 — Tue, 23 Oct 2012 08:35:23 GMT

Documentation says if no "user(XX)" or "group(XX)" is used in the BPMN, group is presumed. This is something else than "in case of name clash, use the group". So using "user(john), test" is actually seen by the engine as "user(john), group(test)".

On top of that, checking the user-management on each assignment to see if it's a user or a group is an unneeded penalty to perform by default. On top of that, no explicit check is done to see if the candidate user/group actually exists.

Why not add this little piece of functionality in your application layer? It's only one call to identityService to check if it's a user/group…

Re: unknown type of task candidate

christoph_retti — Tue, 23 Oct 2012 08:50:59 GMT

Ofcourse I can add this call myself but what I don't like about the solution is that on one side I can let the user choose the delegate
in a user task (we have a Java Swing based application) from a select list, so I have all this information in this place, but in the next task
where the candidates should be set I have to provide two (or three) variables to split each of them in

- assignee
- candidate user
- candidate groups

so (as far as I understand) I would need 3 task variables to properly set the assigment for the next task.

Or is there an approach where I can provide a variable in a list, lets say

"user(frog), group(engineering), group(management)"

and assign this one single task variable? I am not sure if there is a construct where I can specify all types of assignment/candidates in
one task variable and pass it on to the next task?

regards, Chris

Re: unknown type of task candidate

frederikherema1 — Tue, 23 Oct 2012 09:08:40 GMT

If you use a single variable, containing "user(frog), group(engineering), group(management)", you can use it in the <formalExpression> without any problem…

Re: unknown type of task candidate

christoph_retti — Tue, 23 Oct 2012 09:17:37 GMT

ok, I will try this; many thanks for your help

c