Encounter error when List Box inside Table Records

Barry

Question

Hi,

I encounter an error when I put a List Box widget inside a Table Records widget, is it not allowed? because there will be no issue when i move it to outside of the Table Records. Please help.

Below is the error log:

Message:

Object reference not set to an instance of an object.

Stack:

at ssICBWeb.Flows.FlowDocumentManagement.WBlkAttach_Edit.lstListBox1_onDataBinding(Object sender, EventArgs e)
at System.EventHandler.Invoke(Object sender, EventArgs e)
at System.Web.UI.Control.OnDataBinding(EventArgs e)
at System.Web.UI.WebControls.ListControl.OnDataBinding(EventArgs e)
at System.Web.UI.WebControls.ListControl.PerformSelect()
at OutSystems.HubEdition.WebWidgets.ListBox.DataBind()
at System.Web.UI.Control.DataBindChildren()
at System.Web.UI.Control.DataBind(Boolean raiseOnDataBinding)
at OutSystems.HubEdition.WebWidgets.OSDataGridTableCell.DataBind()
at System.Web.UI.Control.DataBindChildren()
at System.Web.UI.Control.DataBind(Boolean raiseOnDataBinding)
at System.Web.UI.WebControls.DataGrid....ontrol.DataBindChildren()
at System.Web.UI.Control.DataBind(Boolean raiseOnDataBinding)
at System.Web.UI.Control.DataBindChildren()
at System.Web.UI.Control.DataBind(Boolean raiseOnDataBinding)
at System.Web.UI.Control.DataBindChildren()
at System.Web.UI.Control.DataBind(Boolean raiseOnDataBinding)
at OutSystems.HubEdition.WebWidgets.OSPage.DataBind()
at ssICBWeb.Flows.FlowDocumentManagement.ScrnDocumentEdit.DataBind()
at ssICBWeb.Flows.FlowDocumentManagement.ScrnDocumentEdit.Page_Load(Object sender, EventArgs e)
at System.Web.UI.Control.OnLoad(EventArgs e)
at System.Web.UI.Control.LoadRecursive()
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
-Env-
eSpaceVer: 258 (Id=104114, PubId=98508, CompiledWith=7.0.1.5)
RequestUrl: https://agiledev.ncs.com.sg/ICBWeb/DocumentEdit.aspx?Id=2ZVqqZzUMAA9pJbnpruyZg== (Method: GET)
AppDomain: /LM/W3SVC/1/ROOT/ICBWeb-330-130361688292158971
FilePath: C:\...\PS\running\ICBWeb.0378806453\DocumentEdit.aspx
Locale: en-US
DateFormat: dd-MM-yyyy
PID: 5928 ('w3wp', Started='4/2/2014 11:39:23 AM', Priv=2130Mb, Virt=8536Mb)
TID: 29
Thread Name:
.NET: 2.0.50727.5472

06 Feb 2014

Daniel Luz

Staff

Hi Hui,

Can you attach your eSpace?
I'm pretty sure I ran into something similar a long while ago but I can't remember the situation. Maybe seeing your eSpace will remind me.

Cheers,
Daniel

07 Feb 2014

Barry

Hi, Daniel

Thanks for your reply, and I attached a eSpace with a simple example.

TestListBox.oml

10 Feb 2014

Daniel Luz

Staff

Hi Hui,

I believe this is indeed a limitation of the platform.
I attached a new version of your example that uses web blocks to wrap the list boxes. This works, but it's a bit clunkier of course.

I used an input parameter to pass the choice list into the web block, and then NotifyWidget to pass the selection list back to the main page. This was to keep the idea in your example.
However, in a real scenario I think it would be better to have the web block get the data from the DB to initialize the list box, and then update the changes directly on the DB.

I hope this helps. Cheers.

Oh, I used my Personal Edition to work on this, so I had to upgrade your module to version 8.
If you don't have access to version 8 yet, it's a great excuse to get your Personal Edition ;)
Check out https://www.outsystems.com/get-started/

TestListBox.oml

11 Feb 2014

Barry

Hi, Daniel

Really appreciate your help, if it's a limitation, then no chioce, better to use your way.

13 Feb 2014

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