Does anyone know if attributes get attached to headline elements during the export process? I am writing a derived backend in which I would like to have a line like

(let (add-toggle (org-export-read-attribute :attr_canvas_html headline :toggle))

....)

But as var as i can tell, the call to org-rexport-read-attribute always evaluates to nil in a file like this:

#+ATTR_CANVAS_HTML: :toggle t

* My TOggle Headline

Am I missing something obvious, or is htis not possible? I notice that none of the org-xxx-headline functions in ox-xxx.el seem to check for attributes, so maybe this is by design?

THanks,

Matt