It's a web-services based search application. I'm basically lazy- loading search results into a collection in chunks of 20 or so. The chunks may be non-sequential, so I pad the ArrayCollection with empty items that are replaced as they become available.
>From what you're saying, disableAutoUpdate was actually intended to work in the other direction - when updating the server with data changes from the collection? As a followup question, I've noticed that bindings in general tend to fire more often than I'd expect. In some cases, 4 times for one update. Can you offer some general ideas on what might cause bindings to fire multiple times for a single update? --- In [email protected], "Alex Harui" <[EMAIL PROTECTED]> wrote: > > When the collection is synced to the server, as you edit fields in an > item, you don't want to push it for every field, just once when done > with the item. > > Clearly if you only change a small % of the items you should not reset > the whole thing. What are you binding to that gets all the traffic? > > ________________________________ > > From: [email protected] [mailto:[EMAIL PROTECTED] On > Behalf Of t0ml33 > Sent: Tuesday, November 27, 2007 1:04 PM > To: [email protected] > Subject: [flexcoders] Re: ListCollectionView dispatches too many > CollectionEvents after enableAutoUpdate > > > > Thanks for the response, Alex. I understand that for most use cases, > it would suffice to set a new source. However, I believe that > approach somewhat defeats the purpose of databinding. Suppose you're > bind to an ArrayCollection with 1000 items and you need to change > 20? Should you clone the ArrayCollection, change the 20 items, and > then rebind? Should you update the existing ArrayCollection and have > the rest take care of itself? I prefer the latter - it's much > cleaner. However, I also don't want my bindings firing 20 times in a > row. > > Was there a particular use-case in mind when it was decided that only > update events would be queued? It would help me better understand > enable/disableAutoUpdate to know. > > --- In [email protected] <mailto:flexcoders% 40yahoogroups.com> > , "Alex Harui" <aharui@> wrote: > > > > I suppose we should have called it "queueUpUpdatesUntilLater" and > > "sendAllQueuedUpUpdatees". > > > > > > > > IMHO, there's an upper limit where, instead of changing piecemeal, > you > > should just set a new source, which should just send one big RESET > > event. > > > > > > > > ________________________________ > > > > From: [email protected] <mailto:flexcoders% 40yahoogroups.com> > > [mailto:[email protected] <mailto:flexcoders% 40yahoogroups.com> > ] On > > Behalf Of t0ml33 > > Sent: Wednesday, November 21, 2007 11:58 AM > > To: [email protected] <mailto:flexcoders% 40yahoogroups.com> > > Subject: [flexcoders] ListCollectionView dispatches too many > > CollectionEvents after enableAutoUpdate > > > > > > > > I am making some updates to an ArrayCollection. Since it's the > > dataSource for a DataGrid, and I want the binding to update as few > > times as possible, I am using ArrayCollection.disableAutoUpdate (), > > making the changes, and then calling enableAutoUpdate() thinking > that > > this will cause the binding to refresh only once for all the > > changes. This would be the case if the ArrayCollection were > > dispatching events of kind CollectionEventKind.UPDATE. Alas, since > I > > am replacing the items in the ArrayCollection and not merely > updating > > them, it is CollectionEventKind.REPLACE. As you can see from > > handlePendingUpdates() in ListCollectionView, it only gangs the > > updates into a single refresh if the event.kind == > > CollectionEventKind.UPDATE. All other CollectionEvents are fired > > sequentially, which would seem to defeat the purpose of > > disableAutoUpdate. Could someone clue me in on why this should be > > the case? I'm tempted to monkey-patch around it, and submit a bug. > > See the code below. > > > > Thanks, > > > > -tom > > > > private function handlePendingUpdates():void > > { > > if (pendingUpdates) > > { > > var pu:Array = pendingUpdates; > > pendingUpdates = null; > > > > // Could further optimize to consolidate various events > > // and make a decision if there are too many updates > > // and we should just refresh. > > var singleUpdateEvent:CollectionEvent; > > for (var i:int = 0; i < pu.length; i++) > > { > > var event:CollectionEvent = pu[i]; > > > > // ****** Here's the offending code > > if (event.kind == CollectionEventKind.UPDATE) > > { > > if (!singleUpdateEvent) > > { > > singleUpdateEvent = event; > > } > > else > > { > > for (var j:int = 0; j < event.items.length; > > j++) > > { > > singleUpdateEvent.items.push(event.items > > [j]); > > } > > } > > } > > else > > { > > listChangeHandler(event); > > } > > } > > > > if (singleUpdateEvent) > > { > > listChangeHandler(singleUpdateEvent); > > } > > } > > } > > >
