Display commandButton in some rows only

Question

In my handler, I created a dynamic datatable. How can I add a command button in some rows only ? I tried to use setRendered but it doesn't work...
HtmlDataTable _dataTable = new HtmlDataTable();
_dataTable.setId("table1");
_dataTable.setVar("table1");       
_dataTable.setValueBinding("value", application.createValueBinding(#{lpHandler.shpModel}));
UIColumn _addColumn  = new UIColumn();
HtmlCommandExButton _addCommand = new HtmlCommandExButton(); 
String _addAction = "#{hksHandler.editLPOutcome}";
MethodBinding _addActionBinding = application.createMethodBinding(_addAction,null);
_addCommand.setAction(_addActionBinding);
_addCommand.setRendered(_dataTable.getRowIndex() > 0);
_addColumn.getChildren().add(_addCommand);
_dataTable.getChildren().add(_addColumn);
Thanks in Advance

Answer 1

To expand on this a little more, when you have a data table the components inside the data table only occur once. That is, there is one instance of the command button you have created. During the render process, the subcomponents of the data table are rendered many times, once for each row. What you have done is set the value of the rendered property for the command button once, to whatever static value (_dataTable.getRowIndex() > 0) has at the time you invoke it. So the value for rendered is the same for each row, so you either always get the button or never get the button. In order to make the rendered value dependent on the row, use must set the rendered using a value expression, in the same way you did with the value property for the data table.