TypeError: Error #1009 (null object access) after manually commit of deleteItem

[philip_mair]

Hello!

I'm getting a error with LCDS 3.1.0.315496

I'm using a DataService to edit some entities with

dataService.autoCommit = false;

I fill a arrayCollection like:

dataService.fill(entitiesAC); //fill with all entites

If i want to update a entity i do:

dataService.commit([entitiy]); //works fine

If i want to create a entity i do:

dataService.createItem(entity);
dataService.commit([entity]); //works fine

If i want to undo my made changes i do:

dataService.revertChanges( entity ); //works fine

If i want to delete a entity i do:

dataService.deleteItem( entity );
dataService.commit( [entity] );

In this case the entity will be deleted, but i get this ugly flex error:

TypeError: Error #1009: Cannot access a property or method of a null object reference.
    at mx.data::DataList/getItemIndex()[C:\depot\DataServices\branches\hotfixes\lcds31_hotfixes\frameworks\projects\data\src\mx\data\DataList.as:376]
    at mx.collections::ListCollectionView/getFilteredItemIndex()[E:\dev\4.x\frameworks\projects\framework\src\mx\collections\ListCollectionView.as:710]
    at mx.collections::ListCollectionView/addItemsToView()[E:\dev\4.x\frameworks\projects\framework\src\mx\collections\ListCollectionView.as:1102]
    at mx.collections::ListCollectionView/listChangeHandler()[E:\dev\4.x\frameworks\projects\framework\src\mx\collections\ListCollectionView.as:1284]
    at flash.events::EventDispatcher/dispatchEventFunction()
    at flash.events::EventDispatcher/dispatchEvent()
    at mx.data::DataList/internalDispatchCollectionEvent()[C:\depot\DataServices\branches\hotfixes\lcds31_hotfixes\frameworks\projects\data\src\mx\data\DataList.as:2296]
    at mx.data::DataList/internalDispatchOneAddRemoveEvent()[C:\depot\DataServices\branches\hotfixes\lcds31_hotfixes\frameworks\projects\data\src\mx\data\DataList.as:2285]
    at mx.data::DataList/http://www.adobe.com/2006/flex/mx/internal::applyUpdateCollectionRangeIndex()[C:\depot\DataServices\branches\hotfixes\lcds31_hotfixes\frameworks\projects\data\src\mx\data\DataList.as:1920]
    at mx.data::DataList/http://www.adobe.com/2006/flex/mx/internal::applyUpdateCollection()[C:\depot\DataServices\branches\hotfixes\lcds31_hotfixes\frameworks\projects\data\src\mx\data\DataList.as:1703]
    at mx.data::DataList/http://www.adobe.com/2006/flex/mx/internal::applyPendingUpdateCollections()[C:\depot\DataServices\branches\hotfixes\lcds31_hotfixes\frameworks\projects\data\src\mx\data\DataList.as:1466]
    at mx.data::DataList/http://www.adobe.com/2006/flex/mx/internal::processUpdateCollection()[C:\depot\DataServices\branches\hotfixes\lcds31_hotfixes\frameworks\projects\data\src\mx\data\DataList.as:1634]
    at mx.data::ConcreteDataService/http://www.adobe.com/2006/flex/mx/internal::processUpdateCollection()[C:\depot\DataServices\branches\hotfixes\lcds31_hotfixes\frameworks\projects\data\src\mx\data\ConcreteDataService.as:4683]
    at mx.data::DataStore/http://www.adobe.com/2006/flex/mx/internal::commitResultHandler()[C:\depot\DataServices\branches\hotfixes\lcds31_hotfixes\frameworks\projects\data\src\mx\data\DataStore.as:2264]
    at mx.data::CommitResponder/internalProcessResults()[C:\depot\DataServices\branches\hotfixes\lcds31_hotfixes\frameworks\projects\data\src\mx\data\CommitResponder.as:559]
    at mx.data::CommitResponder/processResult()[C:\depot\DataServices\branches\hotfixes\lcds31_hotfixes\frameworks\projects\data\src\mx\data\CommitResponder.as:487]
    at mx.data::CommitResponder/result()[C:\depot\DataServices\branches\hotfixes\lcds31_hotfixes\frameworks\projects\data\src\mx\data\CommitResponder.as:228]
    at mx.rpc::AsyncRequest/acknowledge()[E:\dev\4.x\frameworks\projects\rpc\src\mx\rpc\AsyncRequest.as:84]
    at NetConnectionMessageResponder/resultHandler()[E:\dev\4.x\frameworks\projects\rpc\src\mx\messaging\channels\NetConnectionChannel.as:547]
    at mx.messaging::MessageResponder/result()[E:\dev\4.x\frameworks\projects\rpc\src\mx\messaging\MessageResponder.as:235]

I don't get any error if i do

dataService.deleteItem( entity );
dataService.commit( ); //but this also will commit unsaved changes in other entities

Thanks for your help

[Former Community Member]

Can you try passing to the commit method, just the entity without putting it into an array? Also, do you have any associations from the deleted entity? If so, by default it will not cascade commit changes to associated items. See here: http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/mx/data/DataManager.html#commit%2...

[philip_mair]

Hi and thanks for your answer!

The entity is not associated with any other entities or contains any other entities ...

How should i pass the entity without putting it into an array, cause the commit mehod looks like:

public function commit(itemsOrCollections:Array = null, cascadeCommit:Boolean = false):mx.rpc:AsyncToken

I also tried cascadeCommit = true without changes ...

The confusing thing is, that the collectionEvent.kind is "add" with collectionEvent.items= [null] .... and it seems that the mx.data::DataList/getItemIndex is not null-safe ...

..... an open source code of LCDS would be nice

So any other ideas?

Thanks

Philip Mair

[philip_mair]

Well i made a workaround for my problem:

protected function initializeHandler(event:FlexEvent):void
{
   //at first fill, the entetiesAC.list will be set to a mx.data.DataList
   numberRangeProxy.fill( entetiesAC );
   //catch the CollectionEvent before the ListCollectionView.listChangeHandler gets the event
   numberRangesAC.list.addEventListener(CollectionEvent.COLLECTION_CHANGE, collectionChangeHandler, false, int.MAX_VALUE, true);
}
protected function collectionChangeHandler(event: CollectionEvent) : void
{
   if(event.kind == "add")
   {
      var i: int;
      while((i=event.items.indexOf(null)) >= 0)
         event.items.splice(i,1); //remove all null items
   }
}

This works for me, but i think it is still a bug of LCDS and should be fixed!

Thanks