Context objects are all elements that can hold other elements. This i box, dialog, dockpanel, mainwindow, masterpage, page, scrollarea, stack, statusbar and tabbedpage.

This are the settings you can use on all object

''ondoneloading'' Used to add a function to call when the context object is done loading all other elements. This is the last thing done in loading the entitlement.
"layout" the layout type to be used if this is a single page element. Values: vbox, hbox, lineform, grid and absolute.
"elements" holds all the sub elements that will be child elements

Main window is a special case. Here the "ondoneloading" action will be done before the statusbar and menubar due to the dual nature as a master page and a mainpage.