[FLEX-29675] TypeError thrown from DataList when calling getItemAt() on managed collection

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Not A Problem
• Affects Version/s: Adobe Flex SDK Previous
• Component/s: Framework Sync
• Environment: Affected OS(s): Windows; Affected OS(s): Windows XP; Language Found: English
• Assignee: Adobe JIRA
• Reporter: Adobe JIRA
• Created: 18/Jul/07 07:01
• Updated: 15/Apr/11 14:48
• Resolved: 05/Sep/07 00:03

Description

Note: Applies to Flex Date Management - I could not see a suitable project / component to assign to.

Detailed reproduction information is going to be difficult because this problem has been experienced on a large development project. I am including evidence of the problem:

Trace output from Error-handling block:

Error #1009: Cannot access a property or method of a null object reference.
TypeError: Error #1009: Cannot access a property or method of a null object reference.
at mx.data::DataList/http://www.adobe.com/2006/flex/mx/internal::getIdentityForIndex()[C:\dev\enterprise_borneo_rc\frameworks\mx\data\DataList.as:1510]
at mx.data::DataList/http://www.adobe.com/2006/flex/mx/internal::requestItemAt()[C:\dev\enterprise_borneo_rc\frameworks\mx\data\DataList.as:911]
at mx.data::DataList/getItemAt()[C:\dev\enterprise_borneo_rc\frameworks\mx\data\DataList.as:261]
at mx.collections::ListCollectionView/getItemAt()[E:\dev\flex_201_borneo\sdk\frameworks\mx\collections\ListCollectionView.as:495]
at...

The call is as follows (names have been changed for confidentiality reasons):

try
{
var item : ItemModel = ItemModel ( items.getItemAt( i ) );
}
catch ( itemPendingError : ItemPendingError )
{
return;
}
catch ( typeError : TypeError )
{
var myTypeError : TypeError = typeError;
trace( new Date() );
trace( myTypeError.message );
trace( myTypeError.getStackTrace() );
return;
}

This call is triggered whenever a CollectionChange event is received from the 'items' collection (for all CollectionEventKinds). The items collection is an instance of ArrayCollection and is not null. The association in the dataservice configuration is one-to-many and is lazy-loaded. The value of 'i' is valid, but does correspond to an instance that is not cached locally.

It is possible that the destination configuration is wrong or our data-associations do not match the configurations, but more diagnostic information from the DataManagementService is required here. I switched on trace-target on the client with a level of '0', but it did not yield any further information. No errors are reported on the server side.

With the exception of this issue, the dataservice appears to be working.