In this type of situation, I would just sort the array on lastUsed
date, and take the last object from the array:
In your customer class:
public NSArray lastUsedCreditCard() {
EOSortOrdering ordering = EOSortOrdering.sortOrderingwithKey
(CreditCard.LastUsedDate, EOSortOrdering.CompareAscending);
return EOSortOrdering.sortedArrayUsingKeyOrderArray(this.creditCards
(), new NSArray(ordering));
}
In code that wants the last credit card from a customer:
CreditCard lastUsedCard = customer.lastUsedCreditCard().lastObject();
Ken
On Aug 29, 2007, at 4:05 PM, Lachlan Scott wrote:
> To meet a client requirement, we want to traverse the object graph
> and compare attributes of related entities.
>
> Specifically, we want to select a user's last-used credit card.
> User has to-many relationship CreditCards to CreditCard. CreditCard
> has a timestamp recording its last use. We wish to compare the
> timestamps and select the last-used CreditCard.
>
> So the credit cards are available through the relationship, and we
> could fix this by spooging stuff into standard Java, or even adding
> flags into the model; but these don't feel right, and we imagine it
> is the sort of thing WO would provide a mechanism for.
>
> Does anyone have any suggestions about which classes we might be
> able to use, here?
>
>
>
> Many thanks
>
>
> Lachlan
>
> --
> Lachlan Scott
> Senior Bloke
> Run The Red (http://www.runthered.com)
> Wellington, New Zealand
> Wk: +64 (0)4 384 6880
> Mb: +64 (0)21 824 244
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