add setting to allow / prevent overlapping slots about react-big-calendar

[Joramt]

Big calendar purpose is to display events on a calendar graphic support. Therefore it makes sense for the events to overlap, as one person might be attending various numerous of events in a single day. This isn't an issue, but simply a request that you'd like big calendar to have to suit your needs.

[jquense]

Generally I think the best way to handle this is to enforce the event overlapping constraints outside of the calendar using the callbacks. I thnk the only things thats missing to allow this usecase is the ability to prevent the actual drag and select to create a an event. theonSelectStart callback already exists it probably makes sense to allow preventDefault in those cases.

[3plusalpha]

Yes, it's a feature request. In my case I want to let users define dates / slots that do not overlap. For example teacher can only teach one class at once.

[3plusalpha]

Callbacks would be a nice generic solution. I would propose to add these two events: onSelect and onSelectEnd.

[3plusalpha]

Thanks! :)