Steve, There's no magic about all this. The original binding was probably affecting the change. It's perfectly possible to have a loose binding.
Have you tried your code since removing the offending line? Paul ----- Original Message ----- From: justSteve To: [email protected] Sent: Sunday, February 24, 2008 9:54 PM Subject: Re: [flexcoders] Where did the value go? Thankx much. I see a bit better where I was misunderstanding Alex, now. As to binding....the intent here is loose coupling of the MVC sort. This view object sends a notification that an item was selected. It's supposed to store that selectItem to the type defined by the Value Object. I've fallen victim to the assumption that if it's typed right for the DG it'll be typed correctly for the form too. They are based on the same VO. What really puzzles me is the lack of explicit error when the typecast fails. Again...i'm in much appreciation for the feedback. It's clear that it's time to pick up unit testing. On 2/24/08, Paul Andrews <[EMAIL PROTECTED]> wrote: Steve, I think Alex has already pointed out the reason you have a problem: selectedItem="{selectedSlide}" Remove this line. If you have a panel that contains fields that should be bound to the selected item, you need to have the binding there, not as above. Paul ----- Original Message ----- From: justSteve To: [email protected] Sent: Saturday, February 23, 2008 3:20 PM Subject: Re: [flexcoders] Where did the value go? Bummer....I was _sure the problem would be the fact that the datagrid didn't have columns for all Slide's properties. But I've since added all Slide's properties to the DG and still the argument comes in null. I tried Beau's suggestion to remove the cast from the call and type the argument to Object. Still valid at the call and null at the argument. Then I changed event.target.selectedItem as Slide to event.target.selectedItem.myIdentity and the functions signature to accept a Number. That works...the correct number is being passed to the handler. I'm tempted to just code a query to the collection that can build a full Slide from the ID property but figure that if I'm not lazy enough to do it right what hope is there for my becoming a good programmer. So clearly the typecasting is misfiring but why no compile _or runtime error? I find that if I intentionally misspell the dataField property of one of the DG's columns, that column comes up blank but others render as expected and, again, no error reported. On 2/22/08, justSteve <[EMAIL PROTECTED]> wrote: @ Alex...i'm unclear about your questions... I have a datagrid that displays a table of all rows of the given collection. When I select a row that record is supposed to display in a separate - a detail - form. The problem probably traces to the fact that the datagrid doesn't define columns for each of the fields specified in the type 'Slide' - the datagrid has columns representing only a subset of the properties in 'Slide'. But if so, shouldn't that cause either a runtime (if not a compile-time) error? thx to all --steve... On 2/22/08, Alex Harui <[EMAIL PROTECTED]> wrote: The DG's selectedItem is bound to selectedSlide so anything that tickles it will reset the selectedItem. Maybe you want to call selectSlide(selectedSlide), or maybe you just want to init selectedItem once and not have it bound permanently? ---------------------------------------------------------------------- From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of justSteve Sent: Friday, February 22, 2008 2:06 PM To: flexcoders Subject: [flexcoders] Where did the value go? I have a datagrid that should send it's selectItem value to a detail form. <mx:DataGrid selectedItem="{selectedSlide}" change="selectSlide(event.target.selectedItem as Slide)" dataProvider="{slides}" > Placing a breakpoint on the change property and observing the event.target.selectedItem value shows the event is carrying the expected info. But when execution reaches the handler: public var selectedSlide:Slide; private function selectSlide(pSlide:Slide):void { selectedSlide = pSlide ; // pSlide is now null. dispatchEvent(new Event(SELECT, true)); } the param is null. How do I go about figuring out where my error is? I reason that if there's something wrong with how I've typed 'Slide' I'd get a compile-time error. many thankx --steve...
