[rules-users] facts hierarchy

[Esteban Aliverti]

Hi,

Is this what you are looking for?

rule "A requires B"
 when
$fact1: NodeFact(id == "A", selected == true, $b: b)
$fact2: NodeFact(this == $b, selected == false,  this DESCENDANT-OF $fact1)
 then
$fact2.setSelected(true);
end

Best,

2010/5/7 Giovanni Motta <mottagio at gmail.com>

> Hi all, i have a question concerning facts hierarchy, i'm looking for some
> hint as i suppose the same problem could have been faced by someone on the
> list.
>
> I try to eplain with an example:
>
> - Suppose to have a tree of facts, each object representing an UI widget.
>    <root>
>     <A id="1">
>           <B />
>     </A>
>     <A id="2">
>           <B />
>     </A>
>   </root>
>
> - The individual elements A(1), B, A(2), B are mapped to facts, that are
> inserted in a KnowledgeStatefulSession
> - A rule exists that states that when an object A is selected, the B object
> is automatically selected
> - An event occurs that causes selection of node A(1)
>
> The expected result is, obviously, that only the B element that is
> descendant of A(1) must be automatically selected
>
> I'm trying a way to express the 'descendant' relationship in LHS construct.
> The rule will look like:
>
> rule "A requires B"
> when
>  $fact1: NodeFact(id == "A", selected == true)
> $fact2: NodeFact(id == "B", selected == false,  this DESCENDANT-OF $fact1)
>  then
> $fact2.setSelected(true);
> end
>
>
> What is, in your opinion, the best way to handle this situation? What
> should replace the fake "DESCENDANT-OF" match?
> Do i need to use a function that returns the list of descendant nodes of
> $fact1 and then match $fact2 against that?
> Will this be fast when dealing with large trees?
>
> Any suggestion will be appreciated, thank you.
> Giovanni
>
> _______________________________________________
> rules-users mailing list
> rules-users at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
>


-- 
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

Esteban Aliverti
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/rules-users/attachments/20100507/9c6e8557/attachment.html