Remove attach_to_menu feature

The attach-page-to-menu button in the page form was meant as a transitional feature for introducing menus. Now that they have been established and managing menus has been refined we can remove this rather complex feature.

app/models/alchemy/page.rb

@@ -138,9 +138,6 @@ class Page < BaseRecord
     after_update :create_legacy_url,
       if: :saved_change_to_urlname?
 
-    after_update :attach_to_menu!,
-      if: :should_attach_to_menu?
-
     after_update -> { nodes.update_all(updated_at: Time.current) }
 
     # Concerns
@@ -152,8 +149,6 @@ class Page < BaseRecord
     # site_name accessor
     delegate :name, to: :site, prefix: true, allow_nil: true
 
-    attr_accessor :menu_id
-
     # Class methods
     #
     class << self
@@ -545,18 +540,5 @@ def create_legacy_url
     def set_published_at
       self.published_at = Time.current
     end
-
-    def attach_to_menu!
-      node = Alchemy::Node.find_by!(id: menu_id, language_id: language_id)
-      node.children.create!(
-        language_id: language_id,
-        page_id: id,
-        name: name,
-      )
-    end
-
-    def should_attach_to_menu?
-      menu_id.present? && nodes.none?
-    end
   end
 end

app/views/alchemy/admin/pages/_form.html.erb

@@ -10,7 +10,7 @@
     <div class="control_group">
       <%= render 'alchemy/admin/pages/publication_fields' %>
       <%= page_status_checkbox(@page, :restricted) %>
-      <%= render 'alchemy/admin/pages/menu_fields', f: f %>
+      <%= page_status_checkbox(@page, :visible) %>
       <% if configuration(:sitemap)['show_flag'] %>
         <%= page_status_checkbox(@page, :sitemap) %>
       <% end %>

spec/models/alchemy/page_spec.rb

@@ -1991,45 +1991,6 @@ module Alchemy
       end
     end
 
-    describe "#attach_to_menu!" do
-      let(:page) { create(:alchemy_page) }
-
-      context "if menu_id is set" do
-        let(:root_node) { create(:alchemy_node) }
-
-        before do
-          page.menu_id = root_node.id
-        end
-
-        context "and no nodes are present yet" do
-          it "attaches to menu" do
-            expect { page.save }.to change { page.nodes.count }.from(0).to(1)
-          end
-        end
-
-        context "and nodes are already present" do
-          let!(:page_node) { create(:alchemy_node, page: page) }
-
-          it "does not attach to menu" do
-            expect { page.save }.not_to change { page.nodes.count }
-          end
-        end
-      end
-
-      context "if menu_id is not set" do
-        it "does not attach to menu" do
-          expect { page.save }.not_to change { page.nodes.count }
-        end
-      end
-
-      context "if menu_id is empty" do
-        it "does not raise error" do
-          page.menu_id = ""
-          expect { page.save }.not_to raise_error
-        end
-      end
-    end
-
     describe "#nodes" do
       let(:page) { create(:alchemy_page) }
       let(:node) { create(:alchemy_node, page: page, updated_at: 1.hour.ago) }