Unify Flow and Hilla plugins and dependencies

[mshabarov]

Describe your motivation

A hybrid application nowadays requires developers to set the Hilla-originated dependencies in the pom.xml, e.g:

• hilla-maven-plugin (and Gradle plugin as well)
• hilla-react-spring-boot-starter and hilla-spring-boot-starter
• hilla-bom and vaadin-bom
• hilla-react and hilla-lit

These are confusing, hard to maintain and a subject of unification.

Describe the solution you'd like

A hybrid application (using Hilla and Flow views/components) should have only Vaadin-originated dependencies

• vaadin-spring-boot-starter
• vaadin-maven-plugin
• vaadin-bom

Possible solutions:

• Might be enough to set hilla-react-spring-boot-starter as a dependency of vaadin-spring-boot-starter
• The two maven plugins should be combined into a single plugin. Might be easiest to just rename hilla-maven-plugin to vaadin-maven-plugin since it does to my knowledge cover everything currently covered by vaadin-maven-plugin in addition to the stuff specific to Hilla.
• vaadin-maven-plugin after merging with the hilla-maven-plugin should still use the pre-compiled bundles for pure Flow apps. The expected output is that it would see that the Hilla deps are in the classpath and always force the hot deploy mode. That have to be changed (maybe by just removing this logic).

Additional Context

See the discussion in Slack.

[manolo]

But hilla-maven-plugin has different code base to flow-maven-plugin which is the same than vaadin-maven-plugin, so we need somehow to have a mechanism to have both aligned

[knoobie]

Might be enough to set hilla-react-spring-boot-starter as a dependency of vaadin-spring-boot-starter

Please don't bloat the default module; react should be opt-in and not the default for flow apps.

[tarekoraby]

@knoobie, we understand the concern. It's super important to us, too, that Flow apps stay sleek and efficient. And we'll do our best to ensure that adding React won't weigh things down.

Having said that, we also see React as a cool opportunity to give the Vaadin community more options for building awesome web apps. In our view, enabling React support by default for Flow users is an essential component of making Vaadin appealing to a wider audience. It's a bit of a balancing act, and we will do our best to keep things as light and nimble as possible for pure Java developers.

[Legioth]

Two additional things to mention:

• We want to have React Router used by default so that you won't get subtle changes in how routing works just because you add a (React) Hilla view to the application.
• There should be an option to exclude React even if it's included by default.

[knoobie]

Yeah, I've noticed the React Router in the other PR. I've come to terms with it, because it removes the vaadin-router - which doesn't look like it gets much love ;)

Like in the past with Vaadin Connect; it should be possible to exclude hilla-* from vaadin-core and the whole application should work. (yes, React Router can stay)

[Legioth]

it should be possible to exclude hilla-* from vaadin-core and the whole application should work. (yes, React Router can stay)

That is indeed the plan.

[mshabarov]

Below are listed the sub-tasks that we have to do:

• Add Hilla module as a dependency to Platform platform#4934
• Remove hilla-*-spring-boot-starter modules hilla#1979
• Auto-detect if React or Lit is used in a project #18505
• Add Vaadin react-component into version.json platform#4936
• Include react-components into package.json #18506
• Include Hilla maven plugin into Platform platform#4944
• Include Hilla gradle plugin into Platform platform#4945
• Include hilla-dev-mode to platform platform#4946
• Prototype splitting packages [2 days] react-components#229
• Pre-compiled bundles feature works as before with Unified Platform #18529