add_yaml

spec/yaml_spec.cr

@@ -25,3 +25,32 @@ it "load world from yaml" do
   world2.query(Supported).first.getSupported.should eq Supported.new(1, 2)
   world2.query(Unsupported).should be_empty
 end
+
+it "add entities from yaml" do
+  world1 = ECS::World.new
+  world1.new_entity.add(Supported.new(1, 2))
+  world1.new_entity.add(Unsupported.new(3, 4))
+  yaml = world1.to_yaml
+  world2 = ECS::World.new
+  world2.new_entity.add(Supported.new(10, 20))
+  world2.add_yaml(yaml)
+  world2.query(Supported).to_a.map(&.getSupported).should eq [Supported.new(10, 20), Supported.new(1, 2)]
+  world2.query(Unsupported).should be_empty
+end
+
+record WithLink < ECS::YAMLComponent, link : ECS::Entity
+
+it "keep links to entities" do
+  world1 = ECS::World.new
+  ent1 = world1.new_entity
+  ent2 = world1.new_entity
+  ent3 = world1.new_entity
+  ent2.add(Supported.new(1, 2))
+  ent1.add(WithLink.new(ent3))
+  ent3.add(WithLink.new(ent2))
+  yaml = world1.to_yaml
+  world2 = ECS::World.new
+  world2.new_entity.add(Supported.new(10, 20))
+  world2.add_yaml(yaml)
+  world2.query(WithLink).first.getWithLink.link.getWithLink.link.getSupported.should eq Supported.new(1, 2)
+end

src/myecs.cr

@@ -4,6 +4,9 @@ module ECS
   # :nodoc:
   COMP_INDICES = {} of Component.class => Int32
 
+  # :nodoc:
+  WORLD_BEING_LOADED = {} of Fiber => ECS::World
+
   # Component - container for user data without / with small logic inside.
   # All components should be inherited from `ECS::Component`
   @[Packed]
@@ -116,6 +119,16 @@ module ECS
       @world.check_gc_entity @id
     end
 
+    def to_cannon_io(io)
+      io.write_bytes self.id
+      io
+    end
+
+    def self.from_cannon_io(io) : self
+      id = io.read_bytes(EntityID)
+      self.new(WORLD_BEING_LOADED[Fiber.current], id)
+    end
+
     macro finished
       {% for obj in Component.all_subclasses %} 
       {% obj_name = obj.id.split("::").last.id %}
@@ -708,7 +721,13 @@ module ECS
     def decode(io)
       @free_entities = Cannon.decode(io, typeof(@free_entities))
       @count_components = Cannon.decode(io, typeof(@count_components))
-      @pools.each &.decode(io)
+      raise "recurrent deserialization is not supported" if WORLD_BEING_LOADED.has_key?(Fiber.current)
+      WORLD_BEING_LOADED[Fiber.current] = self
+      begin
+        @pools.each &.decode(io)
+      ensure
+        WORLD_BEING_LOADED.delete Fiber.current
+      end
     end
   end
 

src/yaml.cr

@@ -120,7 +120,9 @@ module ECS
   struct Entity
     def self.new(ctx : YAML::ParseContext, node : YAML::Nodes::Node)
       name = String.new(ctx, node)
-      storage = ctx.read_alias(FakeNode.new("_ecs_storage"), EntitiesHash)
+      # storage = ctx.read_alias(FakeNode.new("_ecs_storage"), EntitiesHash)
+      object_id, _ = ctx.@anchors["_ecs_storage"]
+      storage = Pointer(Void).new(object_id).as(EntitiesHash)
       storage.storage[name]
     end
 
@@ -157,16 +159,31 @@ module ECS
 
     def self.new(ctx : YAML::ParseContext, node : YAML::Nodes::Node)
       world = self.new
-      storage = EntitiesHash.new(world)
-      ctx.record_anchor(FakeNode.new("_ecs_storage"), storage)
+      names = EntitiesHash.new(world)
+      ctx.record_anchor(FakeNode.new("_ecs_storage"), names)
       stubs = Hash(String, Array(YAMLComponent)).new(ctx, node)
       stubs.each do |k, v|
-        ent = storage.storage[k]
+        ent = names.storage[k]
         v.each do |comp|
           ent.add(comp)
         end
       end
       world
     end
+
+    def add_yaml(io, names : EntitiesHash? = nil)
+      names = EntitiesHash.new(self) unless names
+      ctx = YAML::ParseContext.new
+      node = YAML::Nodes.parse(io).nodes.first
+      ctx.record_anchor(FakeNode.new("_ecs_storage"), names)
+      stubs = Hash(String, Array(YAMLComponent)).new(ctx, node)
+      stubs.each do |k, v|
+        ent = names.storage[k]
+        v.each do |comp|
+          ent.add(comp)
+        end
+      end
+      self
+    end
   end
 end