Related #189, maybe it’s time to consider a new major version that removes d3.event. Instead of temporarily setting a global, how about event listeners simply receive the current event as an argument, as is the standard behavior outside of D3? To further access the bound data (and index/group), the data could be passed as the second argument. And we could drop the additional index and group arguments, and require you to use selection.each if you want to capture that state.

TODO

• Remove d3.event
• Remove d3.customEvent
• Remove d3.mouse
• Remove d3.touch
• Remove d3.touches
• Remove sourceEvent (not exported)
• Improve d3.clientPoint, somehow?
• Pass event (and bound data) directly to selection.on listeners
• Don’t capture index and group for selection.on listeners Listeners shouldn’t capture references to their index and group? #189