Add updated_at to pages

db/migrate/20240303091643_add_updated_at_to_pages.rb

@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+ROM::SQL.migration do
+  up do
+    execute <<-SQL
+     CREATE OR REPLACE FUNCTION update_updated_at_column()
+       RETURNS TRIGGER AS $$
+         BEGIN
+          NEW.updated_at = (now() at time zone 'utc');
+          RETURN NEW;
+         END;
+     $$ language 'plpgsql';
+    SQL
+
+    alter_table :pages do 
+      add_column :updated_at, :timestamp
+    end
+
+    run <<-SQL
+      CREATE TRIGGER update_pages_updated_at BEFORE UPDATE
+      ON pages FOR EACH ROW EXECUTE PROCEDURE
+      update_updated_at_column();
+    SQL
+  end
+
+  down do
+    execute("DROP FUNCTION IF EXISTS update_updated_at_column();")
+    
+    run <<-SQL
+      DROP TRIGGER IF EXISTS update_pages_updated_at ON pages;
+    SQL
+
+    alter_table :pages do
+      drop_column :updated_at
+    end
+  end
+end

slices/main/templates/pages/show.html.slim

@@ -5,4 +5,6 @@ article class="mb-12 prose dark:prose-invert max-w-prose mx-auto text-gray-800 d
   h1= page_name
   == page_content
 
+  - if page_updated_at
+    ="Last updated: #{page_updated_at}"
 div class="max-w-screen-md mx-auto border-t border-solid border-gray-200 dark:border-gray-600"

slices/main/views/pages/show.rb

@@ -12,6 +12,10 @@ module Main
           page.name
         end
 
+        expose :page_updated_at do |page|
+          page.updated_at&.strftime("%m/%d/%Y")
+        end
+
         private_expose :page do |slug:|
           page_repo.fetch!(slug: slug)
         end