Qute CDI integration - named dependent bean is destroyed before it's actually used

[mkouba]

The behavior is not standardized anywhere but it would make sense to follow the CDI rules for EL: https://jakarta.ee/specifications/cdi/2.0/cdi-spec-2.0.html#dependent_context_ee

NOTE: In this context, "destroyed" means that if a @Dependent bean has a @PreDestroy callback associated then this callback is executed before the bean instance is used e.g. to output a value.

[quarkus-bot]

/cc @manovotn

[mkouba]

We would have to introduce some kind of "expression evaluated callback" in order to implement this correcly.

Alternatively, we could bind a @Dependent bean to the lifecycle of a TemplateInstance or even to a particular rendering operation. In this case we would have to introduce a counterpart to io.quarkus.qute.TemplateInstance.Initializer or similar mechanism.

[mkouba]

Alternatively, we could bind a @dependent bean to the lifecycle of a TemplateInstance.

We couldn't because the lifecycle of a TemplateInstance is not well-defined, in the sense that there is no "destroy" phase/callback.

[mkouba]

I think that the current behavior makes no sense. However, the CDI rules for EL seem to be quite inefficient. Therefore, in my proposal @Dependent named beans are:

1. Shared accross all expressions for a single rendering operation,
2. Destroyed correctly after the rendering finished.