ClassCastException DropDownByKey as TableCellEditor

Question

I have a context node that has dynamically generated child nodes and attributes. I also have a table that has columns dynamically created and bound to these attributes.
We are running 2004s version 6.40 on the portals.
Some of these dynamic attributes have values assigned to the modifiable simple value sets dynamically and for these I am trying to dynamically create IWDDropDownByKey objects and assign them as the table cell editor for the column. This is resulting in a ClassCastException.
The table exists at design time with two columns and a a table column group. It looks like this:
VAT_Table [Table - Child]
        Sequence [TableColumn - GroupedColumn]
        Inherited [TableColumn - GroupedColumn]
        Characteristics [TableColumnGroup - GroupedColumn]
For each dynamic attribute I am creating a new column and adding it to the Characteristics TableColumnGroup. If the attribute has it's modifiable value set assigned, then I create an IWDDropDownByKey object and assign it as the editor. For example:
//locate the "Characteristics" TableColumnGroup and remove all previous columns...
IWDTable vat_table = (IWDTable) view.getElement("VAT_Table");
IWDTableColumnGroup group = (IWDTableColumnGroup) view.getElement("Characteristics");
group.destroyAllColumns();
* String charact is assigned a value here...
//create new column, assign editor and add to group...
IWDTableColumn newColumn = (IWDTableColumn) view.createElement(IWDTableColumn.class, charact);
IWDCaption newHeader = (IWDCaption) view.createElement(IWDCaption.class, charact + "_HEADER");
newHeader.setText(master.getName());
newHeader.setTooltip(master.getId());
newColumn.setHeader(newHeader);
IWDDropDownByKey newField = (IWDDropDownByKey) view.createElement(IWDDropDownByKey.class, charact + "_EDITOR");
newField.bindSelectedKey(values);
newField.bindEnabled(enabled);
newColumn.setTableCellEditor(newField);
So as I mentioned this code results in a ClassCastException which looks like this (I can't paste the entire thing as it then screws up my post):
java.lang.ClassCastException
at com.sap.tc.webdynpro.clientserver.uielib.standard.impl.TableColumn.getTable(TableColumn.java:2222)
at com.sap.tc.webdynpro.clientserver.uielib.standard.uradapter.DropDownByKeyAdapter.getWidth(DropDownByKeyAdapter.java:637)
at com.sap.tc.ur.renderer.ie6.ComboBoxRenderer.render(ComboBoxRenderer.java:53)

Answer 1

Hi Tom,
Check if the table and the two columns exsiting in design time are all bound to the conext. Also, while creating the new UI elements dynamically through code would require you to first create elements in the view with unique Id (or you can pass null) and then add it under appropriate UI element, say transparent container/group/table. This is not done in the code that you pasted in the thread.
Regards,
Tushar S