Use the already loaded page to find elements

The former implementation loads a new page from the database,
instead of using the already loaded page from the controller.

Only load a page if we pass a page layout string.

This way we can take advantage of eager loading and reduce the amount
of objects in memory

lib/alchemy/elements_finder.rb

@@ -57,13 +57,15 @@ def elements(page:)
 
     attr_reader :page, :options
 
-    def find_elements(page)
-      elements = Alchemy::Element
-        .where(page_id: page_ids(page))
-        .merge(Alchemy::Element.not_nested)
-        .where(fixed: !!options[:fixed])
-        .order(position: :asc)
-        .available
+    def find_elements(page_or_layout)
+      @page = get_page(page_or_layout)
+      return Alchemy::Element.none unless page
+
+      if options[:fixed]
+        elements = page.fixed_elements
+      else
+        elements = page.elements
+      end
 
       if options[:only]
         elements = elements.named(options[:only])
@@ -76,15 +78,16 @@ def find_elements(page)
       elements
     end
 
-    def page_ids(page)
-      case page
+    def get_page(page_or_layout)
+      case page_or_layout
+      when Alchemy::Page
+        page_or_layout
       when String
-        Alchemy::Language.current.pages.where(
-          page_layout: page,
+        Alchemy::Page.find_by(
+          language: Alchemy::Language.current,
+          page_layout: page_or_layout,
           restricted: false
-        ).pluck("#{Alchemy::Page.table_name}.id")
-      when Alchemy::Page
-        page.id
+        )
       end
     end
 

spec/libraries/elements_finder_spec.rb

@@ -157,12 +157,16 @@
       let!(:visible_element) { create(:alchemy_element, public: true, page: page) }
       let!(:hidden_element) { create(:alchemy_element, public: false, page: page) }
 
-      let(:page_2) { create(:alchemy_page, :public, page_layout: 'standard') }
-      let!(:visible_element_2) { create(:alchemy_element, public: true, page: page_2) }
-      let!(:hidden_element_2) { create(:alchemy_element, public: false, page: page_2) }
+      it 'returns all public elements from page with given page layout' do
+        is_expected.to eq([visible_element])
+      end
 
-      it 'returns all public elements from all pages with given page layout' do
-        is_expected.to eq([visible_element, visible_element_2])
+      context 'that is not found' do
+        subject { finder.elements(page: 'foobaz') }
+
+        it 'returns empty active record relation' do
+          is_expected.to eq(Alchemy::Element.none)
+        end
       end
     end