From cc0fd1614ce421e6a640c71a3226446f230bea34 Mon Sep 17 00:00:00 2001
From: Pablo Ariel Mayobre <pablo.a.mayobre@gmail.com>
Date: Tue, 14 Feb 2023 18:14:24 -0300
Subject: [PATCH] Serializable component

You can remove the component to tell Concord an Entity shouldn't be serialized.

It's given automatically on Entity creation, but this can be disabled by changing Entity.SERIALIZE_BY_DEFAULT to false.
---
 concord/builtins/init.lua         |  5 +++++
 concord/builtins/serializable.lua | 12 ++++++++++++
 concord/entity.lua                | 12 +++++++++++-
 concord/world.lua                 |  7 ++++---
 4 files changed, 32 insertions(+), 4 deletions(-)
 create mode 100644 concord/builtins/init.lua
 create mode 100644 concord/builtins/serializable.lua

diff --git a/concord/builtins/init.lua b/concord/builtins/init.lua
new file mode 100644
index 0000000..d5b749d
--- /dev/null
+++ b/concord/builtins/init.lua
@@ -0,0 +1,5 @@
+local PATH = (...):gsub("(%.init)$", "")
+
+return {
+  serializable = require(PATH..".serializable"),
+}
diff --git a/concord/builtins/serializable.lua b/concord/builtins/serializable.lua
new file mode 100644
index 0000000..125f76b
--- /dev/null
+++ b/concord/builtins/serializable.lua
@@ -0,0 +1,12 @@
+local PATH = (...):gsub('%.builtins%.[^%.]+$', '')
+
+local Component = require(PATH..".component")
+
+local Serializable = Component("serializable")
+
+function Serializable:serialize ()
+  -- Don't serialize this Component
+  return nil
+end
+
+return Serializable
\ No newline at end of file
diff --git a/concord/entity.lua b/concord/entity.lua
index fb4617c..ca972e9 100644
--- a/concord/entity.lua
+++ b/concord/entity.lua
@@ -8,7 +8,13 @@ local Components = require(PATH..".components")
 local Type       = require(PATH..".type")
 local Utils      = require(PATH..".utils")
 
-local Entity = {}
+-- Initialize built-in Components (as soon as possible)
+local Builtins   = require(PATH..".builtins")
+
+local Entity = {
+   SERIALIZE_BY_DEFAULT = true,
+}
+
 Entity.__mt = {
    __index = Entity,
 }
@@ -31,6 +37,10 @@ function Entity.new(world)
       world:addEntity(e)
    end
 
+   if Entity.SERIALIZE_BY_DEFAULT then
+      e:give("serializable")
+   end
+
    return e
 end
 
diff --git a/concord/world.lua b/concord/world.lua
index bdd0af5..71b3485 100644
--- a/concord/world.lua
+++ b/concord/world.lua
@@ -323,9 +323,10 @@ function World:serialize()
    for i = 1, self.__entities.size do
       local entity = self.__entities[i]
 
-      local entityData = entity:serialize()
-
-      data[i] = entityData
+      if entity.serializable then
+         local entityData = entity:serialize()
+         table.insert(data, entityData)
+      end
    end
 
    return data