Bug 177439 Need an easy way to determine default value for a dynamic parameter
Currently, I have to bring up the data set editor, preview the results in the data set and make a mental note of the value to use for a report parameter that depends on a data set. It would be nice to have a drop down on the default value field, such as <Select value> which when selected queries the data set and presents me with a list to select from.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ParameterDialog.java
{
				displayName = DISPLAY_NAME_CONTROL_COMBO;
			}
			else if ( PARAM_CONTROL_LIST.equals( type ) )
			{
				displayName = DISPLAY_NAME_CONTROL_LIST;
			}
		}
		return displayName;
	}
	private String validateChoice( SelectionChoice choice, String displayLabel,
			String value )
	{
		String errorMessage = isValidValue( value );
		if ( errorMessage != null )
		{
			return errorMessage;
		}
		String newValue = convertToStandardFormat( value );
		if ( ( displayLabel == null && containValue( choice,
				newValue,
				COLUMN_DISPLAY_TEXT ) )
				|| ( containValue( choice, displayLabel, COLUMN_DISPLAY_TEXT ) ) )
		{
			return ERROR_MSG_DUPLICATED_LABEL;
		}
		if ( containValue( choice, newValue, COLUMN_VALUE ) )
		{
			return ERROR_MSG_DUPLICATED_VALUE;
		}