are loaded via AjaxFramework Handler/getEvent
calls event->toJson for frontend presentation
calls attendee->toJson but adds some transformations
$event is initialized from readForm() method
Attendees are scanned for existing and removed
edit.inc includes the mask with both user and attendee fields
There are suggest-as-you-type autocompleters in the create/edit event forms.
ResourceAutocompleter, ContactAutocompleter and UserAutocompleter are implemented as so-called Imple's - They are an archaic form of ajax framework. We should design replacements for them using horde/http_server and horde/routes.
There is some loss/mismatch of information between users/attendees restored from a saved event and those newly added through the autocompleter. Also, it would be good to have the same window for users and "email attendees" as it feels unnatural to users and also complicates the backend code.