TypeError: _4 is null problem at updateCache

[bbruyn]

I wouldn't doubt that this my problem, but I'm struggling to understand what's happening here and why.

I sometimes get the following stack trace after an update on some ListGrid. I'm still trying to isolate the problem more specifically, but I think it would help me to do that if I could get a hand interpreting the error. Apologies for not having a better handle on it just yet.

3.1d 2012-08-10

13:13:54.984:XRP4:WARN:Log:TypeError: _4 is null
Stack from error.stack:
    unnamed(isc_ResultSet_updateCacheDat) @ ipgui/sc/modules/ISC_DataBinding.js?isc_version=7.0.js:1608
    unnamed(isc_ResultSet_updateCach) @ ipgui/sc/modules/ISC_DataBinding.js?isc_version=7.0.js:1600
    unnamed(isc_ResultSet_handleUpdat) @ ipgui/sc/modules/ISC_DataBinding.js?isc_version=7.0.js:1595
    unnamed(isc_ResultSet_dataSourceDataChange) @ ipgui/sc/modules/ISC_DataBinding.js?isc_version=7.0.js:1591
    unnamed(anonymou) @ ipgui/sc/modules/ISC_Core.js?isc_version=7.0.js:69
    unnamed(isc_DataSource_updateCache) @ ipgui/sc/modules/ISC_DataBinding.js?isc_version=7.0.js:411
    unnamed(isc_c_DataSource_handleUpdat) @ ipgui/sc/modules/ISC_DataBinding.js?isc_version=7.0.js:308
    unnamed(isc_DataSource_fireResponseCallback) @ ipgui/sc/modules/ISC_DataBinding.js?isc_version=7.0.js:617
    unnamed(isc_DataSource__completeResponseProcessin) @ ipgui/sc/modules/ISC_DataBinding.js?isc_version=7.0.js:616
    unnamed(isc_DataSource__handleSCServerRepl) @ ipgui/sc/modules/ISC_DataBinding.js?isc_version=7.0.js:2012
    unnamed(isc_c_Class_fireCallbac) @ ipgui/sc/modules/ISC_Core.js?isc_version=7.0.js:339
    unnamed(isc_Class_fireCallbac) @ ipgui/sc/modules/ISC_Core.js?isc_version=7.0.js:442
    unnamed(isc_c_RPCManager_fireReplyCallbac) @ ipgui/sc/modules/ISC_DataBinding.js?isc_version=7.0.js:1401
    unnamed() @ :224
    unnamed(isc_c_RPCManager_fireReplyCallback) @ ipgui/sc/modules/ISC_DataBinding.js?isc_version=7.0.js:1406
    unnamed(isc_c_RPCManager_performOperationRepl) @ ipgui/sc/modules/ISC_DataBinding.js?isc_version=7.0.js:1400
    unnamed(isc_c_RPCManager__performTransactionRepl) @ ipgui/sc/modules/ISC_DataBinding.js?isc_version=7.0.js:1393
    unnamed(isc_c_RPCManager_performTransactionRepl) @ ipgui/sc/modules/ISC_DataBinding.js?isc_version=7.0.js:1350
    unnamed(anonymou) @ ipgui/sc/modules/ISC_Core.js?isc_version=7.0.js:63
    unnamed(isc_c_Class_fireCallbac) @ ipgui/sc/modules/ISC_Core.js?isc_version=7.0.js:339
    unnamed(isc_c_Comm_performXmlTransactionRepl) @ ipgui/sc/modules/ISC_Core.js?isc_version=7.0.js:1405
    unnamed(anonymou) @ ipgui/sc/modules/ISC_Core.js?isc_version=7.0.js:63
    unnamed(isc_c_Class_fireCallbac) @ ipgui/sc/modules/ISC_Core.js?isc_version=7.0.js:339
    unnamed(isc_c_Comm__fireXMLCallbac) @ ipgui/sc/modules/ISC_Core.js?isc_version=7.0.js:1378
    unnamed() @ ipgui/sc/modules/ISC_Core.js?isc_version=7.0.js:1390
    unnamed() @

[Isomorphic]

It's not quite clear what's going on but it might be a server result being returned that has no primaryKey values, or or might be something like calling invalidateCache() at a sensitive / invalid time.

Enabling the "ResultSet" log should help clarify.

Also, what browser gave you that stack trace?

[bbruyn]

Also, what browser gave you that stack trace?

Heavy sigh. Firefox. I went to double check the minor version and found that I have been mysteriously and unwillingly updated to 14.0.1 from 13.x. The GWT plugin had of course not been updated to match... So I did that just now and this particular problem seems to have gone away.

Sincere apologies for the noise. I should have known.

[freelancer]

I've had the same issue with v8.3p_2014-06-27/PowerEdition Deployment, on Firefox and Chrome browsers. (Probably all browsers, but these were tried.)

It was caused by having an instantiated ListGrid that was added to, then later removed from the DOM. As part of the navigation logic, I removed the components not visible to the user. (Then later re-added them again when the user navigated to that screen again.)
When I modified this code to hide components instead of removing them, the issue was fixed.