Task order

[NicolasLacroix]

Fix the task order issue for the merging step.

Description : The graphical order is different than the tasks order in the XML code. When a user duplicate a task, this task is graphically located according to the user wishes but it is not the case in the XML code. As a consequence, constraints are distorted due to a bad order.

Example :

original workflow :

graphical order : tA-tC
XML order : tA-tC

modified workflow (tA is duplicated as a new task tB) :

graphical order : tA-tB-tC
XML order : tA-tC-tB

Proposition : Consider the graphical order

[MireilleBF]

I'm not sure I understand the bug. Why does it matter? For equivalency? To generate a workflow?

Perhaps we need to explore automatic workflow generation based on a set of tasks and a meta-flow to consider potential problems?

[NicolasLacroix]

Let's consider a constraint :

• on a MetaWF : MetaWF => metaA & metaC

• on one of its instances instanceWF modified graphically like : instanceWF => instA & instB & instC
  (where instA and instB refer to metaA and instC refers to metaC)

In the XML code, the representation is the following : instanceWF => instA & instC & instB.

The problem is that the constraint in the FM will be the one in the XML code : instanceWF => instA & instC & instB which will fail because we have in fact : instanceWF => metaA & metaC & metaA which is wrong considering the MetaWF constraint.

[MireilleBF]

? No we should have.
instanceWF => MetaWF.
instanceWF => instA & instC & instB

Is there something wrong?

[NicolasLacroix]

Maybe it is not clear.
The user wants the instanceWF to be composed of instA & instB & instC in this order but in the XML code and thus for merged constraints, it will be instA & instC & instB which causes an error regarding the MetaWF constraint that implies to have all metaA instances preceding the metaC instances.
Effectively, the MetaWF constraint allows :

instA & instB & instC
<=>
(metaA & metaA) & metaC
<=>
metaA & metaC

but not :

instA & instC & instB
=>
(metaA & metaC & metaA) != (metaA & metaA & metaC)
<=>
(metaA & metaC & metaA) != (metaA & metaC)