Thanks for the replies. Well, Jitendra's solution worked only when I created a ComboBox subclass that did take a special equals() (based on the value of a property named "id") into account. Basically, I overrode the selectedItem property in this subclass.
I think equals() and hashCode() are absolutely important, and I find that it's a pain that Flex doesn't have them: In collection contains() methods, selecting items in controls, etc., an equals() semantic is really important. There are many duplicate objects that are semantically equivalent in RIA clients, and without well-defined semantics for equality I'm finding that I have to implement this sort of logic in components myself. Any chance that this may be addressed in forthcoming Flex versions? Thanks, -- Frank --- In flexcoders@yahoogroups.com, Maciek Sakrejda <[EMAIL PROTECTED]> wrote: > > Frank, > > There's no .equals() in actionscript unless you implement it yourself. > Without hearing more about the context, it's hard to tell whether > Jitendra's data binding solution would work for this specific problem > (data binding would effectively set the list selection to an object that > is not in the list--I'm not sure what happens there), but you might run > into a need for .equals() further down the line. We did, and since all > of our VOs inherit from one VO base object, we just implement .equals() > in these as necessary. It seems rather horrifying that there's > no .equals() at first, but you don't really need it that often... > > -- > Maciek Sakrejda > Truviso, Inc. > http://www.truviso.com > > -----Original Message----- > From: frank_sommers <[EMAIL PROTECTED]> > Reply-To: flexcoders@yahoogroups.com > To: flexcoders@yahoogroups.com > Subject: [flexcoders] Java-like equals() method? > Date: Sat, 11 Oct 2008 02:54:18 -0000 > > Hi, > > I've been searching for a good solution to implementing object equality. > I'm familiar with > ObjectUtil, etc., but it still makes things harder than they should be. > > It may be best to illustrate this with an example. Suppose I have a > ComboBox with an > ArrayCollection as a data provider. The ArrayCollection is populated > with value objects > from the server, e.g., User objects. Suppose that I have a Task class, > and a Task may > have an assignedToUser property, which is a User instance. When the > someone selects a > Task (say, in a master-detail view), I would like the ComboBox to set > its selectedItem to > the user for the given Task, i.e., combBox.selectedItem = > myUser.assignedToUser. > > The problem is that no Task in the ComboBox's data provider and the > User's > assignedToUser property are ever equal using the == or === operators. > > So I would like to implement a custom equality for User, and have the > ComboBox use that > to set its selectedItem to the specified user. In Java, this is easily > done by overriding the > equals() and hashCode() methods of User. > > Any suggestions on how to achieve something similar in Flex would be > much appreciated. > > Thanks, > > -- Frank >
