Add SDG LocalTarget model

app/models/concerns/sdg/relatable.rb

@@ -4,7 +4,7 @@ module SDG::Relatable
   included do
     has_many :sdg_relations, as: :relatable, dependent: :destroy, class_name: "SDG::Relation"
 
-    %w[SDG::Goal SDG::Target].each do |sdg_type|
+    %w[SDG::Goal SDG::Target SDG::LocalTarget].each do |sdg_type|
       has_many sdg_type.constantize.table_name.to_sym,
                through: :sdg_relations,
                source: :related_sdg,

app/models/sdg/local_target.rb

@@ -0,0 +1,37 @@
+class SDG::LocalTarget < ApplicationRecord
+  include Comparable
+  include SDG::Related
+
+  delegate :goal, to: :target
+
+  translates :title, touch: true
+  translates :description, touch: true
+  include Globalizable
+
+  validates_translation :title, presence: true
+  validates_translation :description, presence: true
+
+  validates :code, presence: true, uniqueness: true,
+    format: ->(local_target) { /\A#{local_target.target&.code}\.\d+/ }
+  validates :target, presence: true
+
+  belongs_to :target
+
+  def <=>(local_target)
+    return unless local_target.class == self.class
+
+    [target, numeric_subcode] <=> [local_target.target, local_target.numeric_subcode]
+  end
+
+  protected
+
+    def numeric_subcode
+      subcode.to_i
+    end
+
+  private
+
+    def subcode
+      code.split(".").last
+    end
+end

app/models/sdg/target.rb

@@ -6,6 +6,7 @@ class SDG::Target < ApplicationRecord
   validates :goal, presence: true
 
   belongs_to :goal
+  has_many :local_targets, dependent: :destroy
 
   def title
     I18n.t("sdg.goals.goal_#{goal.code}.targets.target_#{code_key}.title")