[LiveComponent] [ComponentWithFormTrait] Force recreation of FormView on PreReRender hook to synchronize FormInstance and FormView.

[Mauriceu]

Q	A
Bug fix?	yes
New feature?	no
Issues	Fix #1981
License	MIT

ComponentWithFormTrait will now recreate the existing FormView in its PreReRender-Hook submitFormOnRender() to synchronize FormView and FormInstance to reflect any manual changes to the FormInstance.
This primarily solves the Problem of manually added FormErrors not being rendered.

[Mauriceu]

Recreating the FormView may lead to unwanted behavior regarding the isValidated and validatedFields properties, as they will be set according to the old FormView. However, an issue may only arise when the underlying Code manually changes the value of a given Form/FormChild, which is discouraged anyway after its been submitted.

Also, for performance reasons I would like to avoid adding a second validation.

[Kocal]

It makes sense to me, WDYT @smnandre?

[smnandre]

I'm not 100% sure to be honest, looks to me this could have side effects, especially with recent changes.

I will have a deeper look this week-end.

Also tests here focus only on errors, and not on data. But the added comment states "Recreate the FormView because it has been created by the submitForm() with a FormInterface whose values may have changed".

[Mauriceu]

Also tests here focus only on errors, and not on data.

The data in this case would be the string manually added form error existing in the template, as it was added by the LiveAction.
But I'd gladly add more coverage as needed. This is my first official pull request so I am still getting the hang of it.

[smnandre]

This is my first official pull request so I am still getting the hang of it.

Welcome aboard :)

The data in this case would be the string manually added form error existing in the template

Yes but this change will be executed for every component using this trait, on every re-render.. so there may be other cases :)

[Mauriceu]

Thank you! Finally able to pay some of it back \o/

The added change will force the recreation of the formView only in cases where the shouldAutoSubmitForm property is set to false.
As I understood that could only happen in one of two cases:

1. submitForm() was called before the PreReRender hook is invoked.
2. Manually setting the shouldAutoSubmitForm property to false.

If necessary due to performance implications we could always introduce a function recreateFormView to give the User more control.

Another thought: Is it even necessary to create the formView inside the submitForm() function? We could extract the formValues directly from the instance, and create the formView last when the PreReRender hook is invoked.

[Mauriceu]

Could theoretically potentially maybe also create a wrapper class for the FormInterface tracking all changes. However, I feel like that creates way too much overhead for what this PR is actually trying to solve...manual re-creation of the form is probably the option with the least impact on performance