The NRiModalWin class implements functionality for creating basic modal dialogs. Dialogs are launched using the NRiModalWin::simpleModal() static member functions. At its most basic level, the NRiModalWin class creates a modal dialog with two buttons that can be labeled (e.g. Ok and Cancel). The return value of the NRiModalWin::simpleModal() function is the index of the button the user selected.
Developers can optionally add a child widget to display/retrieve additional info from user (except for NRiDropMenus). However, when the dialog is killed, the child widgets die with the dialog, so to retrieve values from the child widget, we must create a temporary storage plug that we connect to the child widgets value plug.