Fixes #38024 - Add ordering by virtual columns

Author: ofedoren

app/controllers/api/v2/base_controller.rb

@@ -168,6 +168,20 @@ def render_error(error, options = { })
         render options.merge(:template => "api/v2/errors/#{error}",
           :layout => 'api/v2/layouts/error_layout')
       end
+
+      def resource_scope_for_index(...)
+        virt_column = params[:order]&.split(' ')&.first
+        select_method = "select_#{virt_column}"
+        scope = resource_scope(...)
+
+        if virt_column.blank? || resource_class.columns_hash[virt_column] || !scope.respond_to?(select_method)
+          super(...)
+        else
+          ordered_scope = scope.send(select_method).search_for(params[:search]).order(params[:order])
+          return ordered_scope if paginate_options[:per_page] == 'all'
+          ordered_scope.paginate(**paginate_options)
+        end
+      end
     end
   end
 end

app/controllers/application_controller.rb

@@ -397,6 +397,16 @@ def parameter_filter_context
     Foreman::ParameterFilter::Context.new(:ui, controller_name, params[:action])
   end
 
+  def wrap_for_virt_column_select(base_scope)
+    virt_column = params[:order]&.split(' ')&.first
+    select_method = "select_#{virt_column}"
+    if virt_column.blank? || model_of_controller.columns_hash[virt_column] || !base_scope.respond_to?(select_method)
+      base_scope.search_for(params[:search], :order => params[:order]).paginate(:page => params[:page], :per_page => params[:per_page])
+    else
+      base_scope.send(select_method).search_for(params[:search]).order(params[:order]).paginate(:page => params[:page], :per_page => params[:per_page])
+    end
+  end
+
   class << self
     def parameter_filter_context
       Foreman::ParameterFilter::Context.new(:ui, controller_name, nil)

app/controllers/roles_controller.rb

@@ -22,7 +22,7 @@ class RolesController < ApplicationController
 
   def index
     params[:order] ||= 'name'
-    @roles = Role.authorized(:view_roles).search_for(params[:search], :order => params[:order]).paginate(:page => params[:page], :per_page => params[:per_page])
+    @roles = wrap_for_virt_column_select(Role.authorized(:view_roles))
   end
 
   def new

app/models/role.rb

@@ -39,6 +39,7 @@ class Role < ApplicationRecord
     where("#{compare} builtin = 0")
   }
   scope :cloned, -> { where.not(:cloned_from_id => nil) }
+  scope :select_locked, -> { select("roles.*,(origin IS NOT NULL AND builtin <> #{BUILTIN_DEFAULT_ROLE}) as locked") }
 
   validates_lengths_from_database
   before_destroy :check_deletable

developer_docs/how_to_create_a_plugin.asciidoc

@@ -2391,6 +2391,39 @@ Foreman Webhooks plugin ships with an example "Remote Execution Host Job" templa
 
 You can find all observable events by calling `Foreman::EventSubscribers.all_observable_events` in the Rails console.
 
+=== How to order by a virtual column
+_Requires Foreman 3.14 or higher, set `requires_foreman '>= 3.14'` in
+engine.rb_
+
+Foreman provides a wrapper method in `application_controller.rb` to be able to order by virtual columns called
+`wrap_for_virt_column_select`. It can be used in the `index` action of a controller, for example:
+
+[source, ruby]
+....
+# app/controllers/plugin/controller.rb
+def index
+  # Model can be already scoped by other means
+  @objects = wrap_for_virt_column_select(Model)
+end
+....
+
+In order to use this method, the virtual column must be defined in the model by `scope` method from
+`scoped_search` library, for example:
+
+[source, ruby]
+....
+# app/models/model.rb
+scope :select_virtual_column, lambda {
+  select("model_table.*,(column,column2) as virtual_column")
+}
+....
+
+For real example see `app/models/role.rb` and `app/controllers/roles_controller.rb`.
+
+NOTE: API controllers don't have `wrap_for_virt_column_select` available, since it's embedded in
+`resource_scope_for_index`, so as long as you inherit from `Api::V2::BaseController` and use `resource_scope_for_index`
+in `index` action, you should be all set. Although, `select_<virtual_column_name>` scope must be defined in the model.
+
 [[translating]]
 == Translating
 

test/controllers/api/v2/roles_controller_test.rb

@@ -12,6 +12,19 @@ class Api::V2::RolesControllerTest < ActionController::TestCase
     assert_equal Role.order(:name).pluck(:name), roles['results'].map { |r| r['name'] }
   end
 
+  test "should order index by locked" do
+    unlocked_role = FactoryBot.create(:role, :name => "unlocked role", :origin => '', :builtin => 0)
+    get :index, params: { :order => "locked DESC" }
+    assert_response :success
+    roles = ActiveSupport::JSON.decode(@response.body)
+    assert_equal unlocked_role.id, roles['results'].first['id']
+
+    get :index, params: { :order => "locked ASC" }
+    assert_response :success
+    roles = ActiveSupport::JSON.decode(@response.body)
+    assert_not_equal unlocked_role.id, roles['results'].first['id']
+  end
+
   test "should show individual record" do
     get :show, params: { :id => roles(:manager).to_param }
     assert_response :success

test/controllers/roles_controller_test.rb

@@ -61,6 +61,11 @@ class RolesControllerTest < ActionController::TestCase
     assert_not_nil Role.find_by_id(roles(:default_role).id)
   end
 
+  test "should order index by locked" do
+    get :index, params: { order: "locked DESC" }, session: set_session_user
+    assert_response :success
+  end
+
   context "with taxonomies" do
     before do
       @permission1 = FactoryBot.create(:permission, :domain, :name => 'permission1')