observe_postback_notify/2
Handle a javascript notification from the postback handler. The message is the the request, trigger the id of the
element which triggered the postback, and target the id of the element which should receive possible updates.
#postback_notify is also used as an event.
Type:
Return:
undefined or #context{} with the result of the postback
#postback_notify{} properties:
message:
unknowntrigger:
unknowntarget:
unknowndata:
unknown