Somehow, the collection is generating a remove even though you are calling refresh.
Is this intermittent or consistently reproducible? Could you be piling up changes like removing from an old collection then setting a new collection before the remove gets processed from the old? -Alex ________________________________ From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of Webdevotion Sent: Wednesday, October 24, 2007 1:06 PM To: [email protected] Subject: Re: [Flexcoders] Error from mx\controls\listClasses\ListBase.as If found that I do not get the error when I leave this filterfunction out: public function set cables ( k : ArrayCollection ) : void { _cables = new ArrayCollection( k.toArray() ); //_cables.filterFunction = filterCables; // generates error // _cables.refresh(); } private function filterCables( item : ConnectorModel ) : Boolean { return item.value > 0; } On 10/24/07, Alex Harui <[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> > wrote: Are you doing a reset or remove? Are you removing rows that are locked? ________________________________ From: [EMAIL PROTECTED] ups.com <http://ups.com> [mailto:flexcoders@ yahoogroups.com <http://yahoogroups.com> ] On Behalf Of Webdevotion Sent: Wednesday, October 24, 2007 7:43 AM To: [EMAIL PROTECTED] ups.com <http://ups.com> Subject: Re: [Flexcoders] Error from mx\controls\listClasses\ListBase.as That's a good question ... The application is quite big, I'll have to look into that. But yes, it occurs when I go back some screens and reset the dataprovider. Thanks for that fresh insight. On 10/24/07, Daniel Freiman < [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> > wrote: This appears to be happening when you remove an item from the dataProvider. Is there anything unique about the dataProvider or how you're removing the item from the dataProvider? - Dan Freiman On 10/24/07, Webdevotion < [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> > wrote: Hey everyone, I've been hunting a bug down for a while now in a Flex project: This is the generated error: TypeError: Error #1009: Cannot access a property or method of a null object reference. at mx.controls.listClasses::ListBase/collectionChangeHandler() [C:\dev\flex_201_gmc\sdk\frameworks\mx\controls\listClasses\ListBase.as: 6496] at mx.controls.listClasses::TileBase/collectionChangeHandler ()[C:\dev\flex_201_gmc\sdk\frameworks\mx\controls\listClasses\TileBase.a s:1981] at flash.events::EventDispatcher/dispatchEventFunction () at flash.events::EventDispatcher/dispatchEvent() at mx.collections::ListCollectionView/dispatchEvent ()[C:\dev\flex_201_gmc\sdk\frameworks\mx\collections\ListCollection View.as:833 <http://View.as:833> ] at mx.collections::ListCollectionView/moveItemInView ()[C:\dev\flex_201_gmc\sdk\frameworks\mx\collections\ListCollectionVi ew.as:1316 <http://ew.as:1316> ] at mx.collections::ListCollectionView/handlePropertyChangeEvents ()[C:\dev\flex_201_gmc\sdk\frameworks\mx\collections\ListCollection View.as:1124 <http://View.as:1124> ] at mx.collections::ListCollectionView/listChangeHandler ()[C:\dev\flex_201_gmc\sdk\frameworks\mx\collections\ListCollectionVi ew.as:1042 <http://ew.as:1042> ] at flash.events::EventDispatcher/dispatchEventFunction () at flash.events::EventDispatcher/dispatchEvent () at mx.collections::ArrayList/internalDispatchEvent()[C:\dev\flex_201_gmc\sd k\frameworks\mx\collections\ArrayList.as:518] at mx.collections::ArrayList/itemUpdateHandler ()[C:\dev\flex_201_gmc\sdk\frameworks\mx\collections\ArrayList.as:544] at flash.events::EventDispatcher/dispatchEventFunction() at flash.events::EventDispatcher/dispatchEvent() The rule that throws the error // RULE 6493 in ListBase.as //( found at : C:\Program Files\Adobe\Flex Builder 2 Plug-in\Flex SDK 2\frameworks\source\mx\controls\listClasses ) // make sure we've generated rows for the actual data // at startup time we might just have blank rows if (listItems.length && listItems[lockedRowCount].length ) Screenshot For those interested, this is the dump of listItems: screenshot <http://content.screencast.com/media/d25bbc5a-9b36-42ee-8393-b2e2f48929f 8_8373bf5e-323c-46b9-94a3-68ac1e9fbb8f_static_0_0_image.png> Any thought are greatly appreciated! Bram
