TextSupport#layout

A view may contain a layout. A layout is a regular template but supersedes the template property during rendering. It is the responsibility of the layout template to retrieve the template property from the view (or alternatively, call Handlebars.helpers.yield, {{yield}}) to render it in the correct location.

This is useful for a view that has a shared wrapper, but which delegates the rendering of the contents of the wrapper to the template property on a subclass.