Menu Link Discovery takes forever on huge websites

I think it would be a good idea to make this an opt-in thing via config.

I've got a few sites where I'm nixing the logic via a hook_module_implements_alter to remove this hook from the module.

Actually, I think it would be better to add a flag to the microsite entity 'derive menus' and consult that.

I'll be working on a new client site that will likely need this in the next month, so will try to tackle it as part of that.

Here is my initial run at an 'opt-in' menu building system for microsites.

This still needs to have 'discovered' set against all the menu items (menu_tree table) in the hook_update_N (except the ones with an override content entity).

I also believe we no longer need the override content entity and it can be done with core, but that's a bigger problem that I can work on after this one. That will be enabled by having 'discovered' => 1 on generated menu items.

+++ b/modules/entity_hierarchy_microsite/src/Entity/Microsite.php
@@ -123,6 +137,13 @@ class Microsite extends ContentEntityBase implements MicrositeInterface {
+  public function shouldGenerateMenu() {

+++ b/modules/entity_hierarchy_microsite/src/Entity/MicrositeInterface.php
@@ -25,4 +25,12 @@ interface MicrositeInterface extends ContentEntityInterface {
+  public function shouldGenerateMenu();

Let's add a :bool return type hint here

I also believe we no longer need the override content entity and it can be done with core

- that was a deliberate design decision. We want the overrides managed in content and not in configuration. So I don't want to change that behaviour.

Marking needs review for the sake of the bot

We'll need an update hook here to add the new field

This is also a bug now

Including my forgotten update hook.
Updating with the boolean typehint.

Picking this up

Test fixes

One test caught we lost the protection against exceeding max depth of 9, so added in new code for that.

And with an update path test

Additional update path to mark all old items as discovered so they should be cleaned up if the content is no longer in the tree

Some changes identified by @nterbogt