You are correct that you have to use setItemAt to update the
ArrayCollection once the result is returned. I tried two ways to
accomplish this...an easy way, and a safer way.
1) EASY. You can create a model.selectedProduct OR
model.selectedProductID on the model (OR pass a reference through
the event and grab it in the Command before the event is dispatched)
to hold the item or index of the selected product that you are
updating. Obviously, the danger to this is that the selection or
collection could change between the call to the server and the
response (unless you prevent this).
2) SAFER. The way i decided to do it is to search for the product ID
in the ArrayCollection, get back an index and then setItemAt that index.
I created this as a static function and put it in a utilities class.
public static function getItemIndex
(ac:ArrayCollection,value:Object,fld:String):int{
var arraylen:Number = ac.length;
for (var i:int=0;i<arraylen;i++){
var test:String = ac.getItemAt(i)[fld];
if(ac.getItemAt(i)[fld] == value){
return i;
}
}
return NaN;
}
Then I do the following each time a get a result back from the
server. (Obviously, your object must contain some unique ID)
//next find index of updated record
var index:Number = ArrayCollectionUtil.getItemIndex
(model.someList,data.result['someObject'].id,'id');
//set updated record as selected
model.someList.setItemAt(data.result[' someObject'],index);
You could extend your ArrayCollection Class to do this all in one
step, but it's not too bad this way. Honestly, this doesn't feel
like the cleanest solution, but it does feel safer to do it this way
then take the risk that the ArrayCollection or selectedItem could
somehow change in the time it takes your result to be returned.
Obviously, you would then be updating the wrong item. I guess it all
depends on the complexity of your program.
Let me know if you think of a better way to do it.
- Kevin
On Apr 12, 2007, at 6:38 PM, Dan wrote:
Hey thanks,
What I'm trying to reference is the specific object in an array
collection that i have stored in the modelLocator. Similar to one
of your earlier scenarios I am using a grid to edit a list of
products and prices. After a product is edited and the changes are
sent and updated on the database side and returning a success to
flex i want to update the arraycollection in the modelLocator
feeding my grid so that the save is reflected.
It seems to me that you have to use the setItemAt(item:Object,
index:int ) function to update the arrayCollection, so I was
wondering how you get the index number and what is the best way to
pass the new object to this function.
-Dan
On Mar 13, 2007, at 5:11 PM, Kevin wrote:
the solution below works:
On Mar 13, 2007, at 4:48 PM, Kevin wrote:
someone else was saying that I might be able to pass
"model.userState.currentUser" as one property "source" and then
the field as "fld".
I would then try to call this in the Command: source[fld] =
someData;
I haven't tried this yet, but I will let you know if that works.
- kevin
