Add optionality to answer_option

decidim-module-forms_locations/app/models/concerns/decidim/forms_locations/answer_choice_extensions.rb

@@ -6,15 +6,24 @@ module AnswerChoiceExtensions
       extend ActiveSupport::Concern
 
       included do
-        belongs_to :location_option,
-                   class_name: "LocationOption",
-                   foreign_key: "decidim_location_option_id",
-                   optional: true
+        # Define a module variable to track if the association has been defined
+        class_attribute :answer_option_association_defined
+        self.answer_option_association_defined = false unless self.answer_option_association_defined
+
+        # Redefine the belongs_to :answer_option association if not already defined
+        unless self.answer_option_association_defined
+          belongs_to :answer_option,
+                    class_name: "AnswerOption",
+                    foreign_key: "decidim_answer_option_id",
+                    optional: true
 
-        belongs_to :answer_option,
-                   class_name: "AnswerOption",
-                   foreign_key: "decidim_answer_option_id",
-                   optional: true
+          self.answer_option_association_defined = true
+        end
+
+        belongs_to :location_option,
+                  class_name: "LocationOption",
+                  foreign_key: "decidim_location_option_id",
+                  optional: true
       end
     end
   end

decidim-module-forms_locations/app/models/decidim/forms/answer_choice.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+module Decidim
+  module Forms
+    class AnswerChoice < Forms::ApplicationRecord
+      belongs_to :answer,
+                 class_name: "Answer",
+                 foreign_key: "decidim_answer_id"
+
+      belongs_to :answer_option,
+                 class_name: "AnswerOption",
+                 foreign_key: "decidim_answer_option_id"
+
+      belongs_to :matrix_row,
+                 class_name: "QuestionMatrixRow",
+                 foreign_key: "decidim_question_matrix_row_id",
+                 optional: true
+
+      validates :matrix_row, presence: true, if: -> { answer.question.matrix? }
+    end
+  end
+end