Entity's Keys

You can now give the 'key' component to Entities.

A key will be generated automatically and stored in Entity.key.value.

You can then use this key to fetch the Entity from the World with World:getEntityByKey(key)

The keys are generated with a generator function that can be overriden.

concord/builtins/key.lua

@@ -0,0 +1,37 @@
+local PATH = (...):gsub('%.builtins%.[^%.]+$', '')
+
+local Component = require(PATH..".component")
+
+local getKey = function (self, key)
+  local entity = self.__entity
+
+  if not entity:inWorld() then
+    error("entity needs to belong to a world")
+  end
+
+  local world = entity:getWorld()
+
+  return world:__assignKey(entity, key)
+end
+
+local Key = Component("key", function (self, key)
+  self.value = getKey(self, key)
+end)
+
+function Key:deserialize (data)
+  self.value = getKey(self, data.value)
+end
+
+function Key:removed (replaced)
+  if not replaced then
+    local entity = self.__entity
+
+    if entity:inWorld() then
+      local world = entity:getWorld()
+  
+      return world:__clearKey(entity)
+    end
+  end
+end
+
+return Key