Merge pull request #1340 from alphagov/add-posgres-notify-trigger

Add Postgres notify trigger for route updates

config/application.rb

@@ -40,6 +40,9 @@ class Application < Rails::Application
     # config.time_zone = "Central Time (US & Canada)"
     # config.eager_load_paths << Rails.root.join("extras")
 
+    # Make sure schema contains triggers
+    config.active_record.schema_format = :sql
+
     # Don't generate system test files.
     config.generators.system_tests = nil
 

db/migrate/20241105135438_add_notify_trigger_for_route_changes.rb

@@ -0,0 +1,38 @@
+class AddNotifyTriggerForRouteChanges < ActiveRecord::Migration[7.2]
+  def up
+    execute <<-SQL
+      CREATE OR REPLACE FUNCTION notify_route_change() RETURNS trigger AS $$
+      BEGIN
+        PERFORM pg_notify('route_changes', '');
+        RETURN OLD;
+      END;
+      $$ LANGUAGE plpgsql;
+    SQL
+
+    execute <<-SQL
+      CREATE TRIGGER content_item_change_trigger
+      AFTER INSERT OR UPDATE OR DELETE ON content_items
+      FOR EACH ROW EXECUTE PROCEDURE notify_route_change();
+    SQL
+
+    execute <<-SQL
+      CREATE TRIGGER publish_intent_change_trigger
+      AFTER INSERT OR UPDATE OR DELETE ON publish_intents
+      FOR EACH ROW EXECUTE PROCEDURE notify_route_change();
+    SQL
+  end
+
+  def down
+    execute <<-SQL
+      DROP TRIGGER IF EXISTS content_item_change_trigger ON content_items;
+    SQL
+
+    execute <<-SQL
+      DROP TRIGGER IF EXISTS publish_intent_change_trigger ON publish_intents;
+    SQL
+
+    execute <<-SQL
+      DROP FUNCTION IF EXISTS notify_route_change();
+    SQL
+  end
+end