Replacing the dataProvider isn't the best option for my particular
application, since requests to add rows will come in at random
intervals, and I don't want to lose selection state and such.
So I've written the code such that, if two add requests happen within
300ms of each other, I call disableAutoUpdate. If, after that, 500ms
go by with no add requests, I call enableAutoUpdate().
But now, adding 1000 rows takes just as long as before. With the tree
collapsed (or with a regular DataGrid), it takes 1 second. With the
tree opened, it takes 8, with or without auto-update.
Any idea why this might be? I can switch to replacing the
dataProvider and only running this optimization when the app first
loads, but I'd rather not.
More information: The dataProvider is a subclass of ArrayCollection,
which contains objects with a "children" member, which is another
ArrayCollection.
private var m_lastAdd:Number = 0;
private var m_autoUpdateEnabled:Boolean = true;
// This is called 1000 times
private function AddItem(name:String):void
{
var now:Number = (new Date()).getTime();
if (m_autoUpdateEnabled && (now - m_lastAdd < 300))
{
gridData.disableAutoUpdate();
m_autoUpdateEnabled = false;
setTimeout(flushAddQueue, 500);
}
m_lastAdd = now;
[Then call the add function, which puts items into the 0th group]
}
private function flushAddQueue():void
{
if (!m_autoUpdateEnabled && ((new Date()).getTime() - m_lastAdd <
300))
{
gridData.enableAutoUpdate();
m_autoUpdateEnabled = true;
}
else
setTimeout(flushAddQueue, 500);
}
Thanks for all your help so far!
--- In [email protected], "Daniel Gold" <[EMAIL PROTECTED]>
wrote:
>
> I've seen a lot of posts with performance related to using Bindable
> Collections like that. One of the dangerous of having such a useful
easy API
> for updating controls...
>
> Just to expand on what Alex is suggesting, suppose your service
call returns
> to a function called updateData, and your control is bound to a
_data
> ArrayCollection
>
> public function updateData(newData:IList):void
> {
> var newData:Array =[];
> for each(var data:Object in IList)
> {
> _newData.push(data);
> }
> _data.source = newData;
> _data.refresh();
> }
>
> That's an extremely basic code example, and actually unnecessary to
loop
> like that in most cases, but basic principle is get your data
structured in
> an Array or similar structure, add new items, remove old
unnecessary items,
> whatever you need to do, concat or replace the source Array of your
> ArrayCollection, and then call refresh which will dispatch a
> COLLECTION_CHANGE event which will trigger any controls using it as
a
> dataProvider to update.
>
> On Thu, Jul 31, 2008 at 6:47 PM, Alex Harui <[EMAIL PROTECTED]> wrote:
>
> > There is enable/disableAutoUpdate, but adding rows one at a
time is
> > inefficient. Just concat the two arrays and replace the
dataprovider
> >
> >
> > ------------------------------
> >
> > *From:* [email protected]
[mailto:[EMAIL PROTECTED] *On
> > Behalf Of *whatabrain
> > *Sent:* Thursday, July 31, 2008 3:23 PM
> > *To:* [email protected]
> > *Subject:* [flexcoders] How to temporarily stop a dataProvider
from
> > updating UI
> >
> >
> >
> > I've found that adding a lot of rows (1000+) to an
AdvancedDataGrid can
> > be quite slow, if the rows happen to be visible (in an open node
of the
> > tree). I don't know why this is the case, especially since it's
not the
> > case in a regular DataGrid, but I'd like to work around it.
> >
> > So how can I tell the AdvancedDataGrid to temporarily ignore
updates to
> > the dataProvider? Once the large number of rows have been added,
I'll
> > turn the automatic updating back on, for the slow trickle of
updates
> > that come after that.
> >
> >
> >
>
