WoW API: CheckInteractDistance

Reference e
AddOns WoW API Widget API XML UI Event API WoW Lua Macro API CVars Battle.net HOWTOs Snippets UI tech Categories

Returns 1 if you are in range of the specified unit to perform the action specified by distIndex (returns nil otherwise).

(String unit, Int distIndex)

unit

The unit to query (e.g. "target", "party1", "pet", "player")

distIndex

A value 1-4:

1 = Inspect, 11.11 yards (prior to Patch 1.12 this was 5.55 yards)

2 = Trade, 11.11 yards

3 = Duel, 10 yards

4 = Follow, ~28 yards

canInteract: If in range to perform the action, 1 (true). Otherwise, nil (false).

If "unit" is a hostile unit, the return values are the same. But you obviously won't be able to do things like Trade.

There may also be more values for distIndex that we don't know about.

if ( CheckInteractDistance("target", 4) ) then
  FollowUnit("target");
else
  -- we're too far away to follow the target
end