Component:removed

When a Component owns something that is not a Lua table — a Box2D body, a LÖVE Canvas, a handle in another library — someone has to destroy it. That someone is Component:removed, not a System that might miss the frame.

When it runs

function Body:removed (replaced)
  if self.fixture then
    self.fixture:destroy()
    self.fixture = nil
  end
end

removed is called when:

Entity:remove takes the Component off (replaced == false)
Entity:give overwrites it (replaced == true)

replaced is how you tell “this Body is gone” from “this Body was replaced by a new one, tear the old fixture down.” The builtin key uses that split: it only clears the World’s key table when the Component is truly gone, not when you assign a new key value.

What it is not

removed is Component teardown. It is not “this Entity left a Pool” — that is Pool onAdded / onRemoved. It is not “this Entity left the World” — that is World:onEntityRemoved.

If you destroy an Entity, Concord removes key first so key:removed(false) still runs. Other Components are not automatically removed one by one; if they own resources, either remove them yourself before destroy, or tear those resources down from onEntityRemoved.

See also