[rules-users] Ordered lists in drl

[Wolfgang Laun]

Is the data originally in XML or a structure comparable to a DOM tree?

If the answer is yes, there is a (admittedly not quite simple) approach
wherewith
you can solve such problems easily. However, it's probably not worth
applying
if there's only one such issue in your app. Just to give you an idea: You
use additional facts describing the structure of your data.

I'll furnish details but not unless it's necessary.

-W

On 18 November 2011 20:18, LCode <j_whittlesea at hotmail.com> wrote:

> I am trying to write a rule via the guided rule editor and (again!!) I am
> really struggling.
>
> The following is a simplified explanation of my scenario:
>
> I have a model where there is one 'Supermarket' object which has a list of
> integers 'locationID'. Elsewhere I have another list of 'Place' objects,
> each of which has an integer locationReference.
>
> Something like this....
>
>                <Supermarket name = 'asda'>
>                        <LocationID>21</LocationID>
>                        <LocationID>18</LocationID>
>                        <LocationID>19</LocationID>
>                </Supermarket>
>
>                <Places>
>                        <Place>
>                                <LocationReference>21</LocationReference>
>                        </Place>
>                        <Place>
>                                <LocationReference>18</LocationReference>
>                        </Place>
>                        <Place>
>                                <LocationReference>19</LocationReference>
>                        </Place>
>                </Places>
>
>
> I need to write a rule that fires when the *order* of locationIDs does not
> match the order of the locationReferences. So the above example would be
> fine but the model below would not...
>
>                <Supermarket name = 'asda'>
>                        <LocationID>18</LocationID>
>                        <LocationID>21</LocationID>
>                        <LocationID>19</LocationID>
>                </Supermarket>
>
>                <Places>
>                        <Place>
>                                <LocationReference>21</LocationReference>
>                        </Place>
>                        <Place>
>                                <LocationReference>18</LocationReference>
>                        </Place>
>                        <Place>
>                                <LocationReference>19</LocationReference>
>                        </Place>
>                </Places>
>
> I know that drools does not consider the order of facts in the model,
> however since both facts are java.util.Lists I wonder if it possible to
> compare the elements at position 0, 1, 2 etc. I am afraid my drl skills are
> really not up to scratch.
>
> Any thoughts?
>
> --
> View this message in context:
> http://drools.46999.n3.nabble.com/Ordered-lists-in-drl-tp3519453p3519453.html
> Sent from the Drools: User forum mailing list archive at Nabble.com.
> _______________________________________________
> rules-users mailing list
> rules-users at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/rules-users/attachments/20111119/0a32f406/attachment.html