In the application I’m working on, a layout renders a partial that
displays a breadcrumb navigation bar across the top of a page. In
other words, the layout renders a partial that displays breadcrumbs.
But the navigation bar rendered by a partial in a layout needs to use
data from the view to determine which breadcrumbs to display.
My question is: how can data be passed from a view to a partial
rendered in a layout? The ActionController::Layout::ClassMethods
explains that data in a view is shared by a partial rendered by the
view (using :locals), but I see no reference for how to pass data from
a view to a partial being rendered in the layout in which the view