[Autocomplete] Opt-out from auto updates if the root has a live id

[1ed]

Q	A
Bug fix?	yes
New feature?	no
Tickets	-
License	MIT

When I have a form with dependent fields I can tell when a dependency changes
and if I use a custom data-live-id attribute which calculated based on the
dependencies the dynamic fields will re-render correctly and fixes the issue
with multi-select fields.

For example this seems to work well:

 public function buildForm(FormBuilderInterface $builder, array $options): void { $builder ->add('department', null, [ 'autocomplete' => true, ]) ; $formModifier = function (FormInterface $form, Department $department = null) { $members = $department ? $this->organizationMemberRepository->findByDepartment($department) : []; $form->add('participatingMembers', null, [ 'autocomplete' => true, 'choices' => $members, 'attr' => [ 'data-live-id' => 'participating-members-'.$department?->getId(), ], ]); }; /// ... }

[weaverryan]

Thanks for this @1ed! Question: does the MutationObserver stuff cause a problem? Your PR definitely makes sene for the multiple autocomplete case (where that simply doesn't work - so we add data-live-ignore and you'd want to avoid that since you're handling it manually). But for the "single" case, even if you ARE adding the data-live-id manually, was the MutationObserver causing some undesirable side effects?

[1ed]

But for the "single" case, even if you ARE adding the data-live-id manually, was the MutationObserver causing some undesirable side effects?

Actually, I didn't tried that scenario, yet. I think it will not cause any problems, but I can check it later. When I add a live-id and it changes it will re-render anyway, won't it? But if the live-id does not change should it have an observer looking for changes? I don't know, I don't have a use case in mind. I've thought, when I add a live-id I want to manually control when the component should re-render, but I'm fine with both ways (with or without the observer).

[weaverryan]

I think it will not cause any problems, but I can check it later

Yes, please let me know! The MutationObserver is a bit of new complexity on Autocomplete, and ideally we won't break existing behavior.

When I add a live-id and it changes it will re-render anyway, won't it?

Yes. Live components should see this as "the old element was removed and a new element was added". In that case, the old element (which would contain a record of the mutations that TomSelect made to it when it was initializing) will be removed and its mutations will be ignored. But, this is something we should actually check ;)

I don't know, I don't have a use case in mind.

I DO think this change is likely valid for the multiple situation. In that case, you might be purposely using data-live-id to "take control"... and so you wouldn't want data-live-ignore added, I think.