Create new contents on demand

app/decorators/alchemy/element_editor.rb

@@ -8,6 +8,17 @@ def to_partial_path
       "alchemy/admin/elements/element"
     end
 
+    # Returns content editor instances for defined contents
+    #
+    # Creates contents on demand if the content is not yet present on the element
+    #
+    # @return Array<Alchemy::ContentEditor>
+    def contents
+      element.definition.fetch(:contents, []).map do |content|
+        Alchemy::ContentEditor.new(find_or_create_content(content[:name]))
+      end
+    end
+
     # CSS classes for the element editor partial.
     def css_classes
       [
@@ -78,5 +89,19 @@ def deprecation_notice
                   default: Alchemy.t(:element_deprecated))
       end
     end
+
+    private
+
+    def find_or_create_content(name)
+      find_content(name) || create_content(name)
+    end
+
+    def find_content(name)
+      element.contents.find { |content| content.name == name }
+    end
+
+    def create_content(name)
+      Alchemy::Content.create(element: element, name: name)
+    end
   end
 end

app/views/alchemy/admin/elements/_element.html.erb

@@ -25,7 +25,7 @@
         <div id="element_<%= element.id %>_errors" class="element_errors"></div>
 
         <div id="element_<%= element.id %>_content" class="element-content-editors">
-          <%= render element.contents.map { |content| Alchemy::ContentEditor.new(content) } %>
+          <%= render element.contents %>
         </div>
 
         <% if element.taggable? %>

spec/decorators/alchemy/element_editor_spec.rb

@@ -12,6 +12,44 @@
     end
   end
 
+  describe "#contents" do
+    let(:element) { create(:alchemy_element, :with_contents, name: "headline") }
+
+    subject(:contents) { element_editor.contents }
+
+    it "returns a ContentEditor instance for each content defined" do
+      aggregate_failures do
+        contents.each do |content|
+          expect(content).to be_an(Alchemy::ContentEditor)
+        end
+      end
+    end
+
+    context "with a content defined but not existing yet" do
+      before do
+        expect(element).to receive(:definition).at_least(:once) do
+          {
+            name: "headline",
+            contents: [
+              {
+                name: "headline",
+                type: "EssenceText",
+              },
+              {
+                name: "foo",
+                type: "EssenceText",
+              },
+            ],
+          }.with_indifferent_access
+        end
+      end
+
+      it "creates the missing content" do
+        expect { subject }.to change { element.contents.count }.by(1)
+      end
+    end
+  end
+
   describe "#to_partial_path" do
     subject { element_editor.to_partial_path }