Add ability to make some views live only in DEV Mode

[abdullahtellioglu]

Describe your motivation

In Copilot, we are aiming to create some example views that should be available only when in development mode. These views should not be exposed to production what so ever.

There is no solution that we can provide right now. Throwing an exception in constructor inside ApplicationConfiguration#isProduction is the best workaround that we have so that users would get 500 internal error in production mode.

Describe the solution you'd like

The best solution that we could think of a new Annotation that filters out route views while generating a production build. Similar to Spring profile, but might be explicit for DevMode only, something like: DevModeOnlyRoute

Describe alternatives you've considered

No other alternatives came to our mind; any possible solution that does not expose specific routes would work.

Additional context

No response

[Legioth]

How about setting registerAtStartup to false in the @Route annotation and then have a service init listener that checks for dev mode and conditionally registers the views with the route registry?

[abdullahtellioglu]

That could work, but having an annotation is still preferred because that solution would require adding/modifying a configuration file.

[Legioth]

What configuration file would that be? A service init listener can be registered with a META-INF/services/com.vaadin.flow.server.VaadinServiceInitListener file anywhere on the classpath.

[abdullahtellioglu]

It is unintuitive to create ServiceInitListener with some predefined code snippet to remove one view from the production build.

Creating such class may not be easy in some cases e.g. spring web with xml configuration or some multi module projects with weird setups etc. Then other steps might require to make that class accessible or might not work at all in some situations

It would be really convenient to have such an annotation

[Artur-]

I don't understand the use case but if Copilot wants to register a view, then why doesn't Copilot do that in its startup listener? Why do you need annotations etc?

[abdullahtellioglu]

There is a new feature where users can generate a view on demand. We also want to keep it in the project codebase so users can edit and share the view with others. Thus, a way to prevent that view from being exposed in production mode is needed

If such an annotation was available, we will add it to the view template and then view would not be accessible in production, thats the use case

[mshabarov]

Another way to do this could be check the mode in before enter listener and prevent the navigation.
Before the outer request for this new annotation, I'd go just with a solution based on current API, even though it's low level and boilerplate.

[mgarciavaadin]

Annotation option would be the ideal case as I think it could be useful for users, I see some use cases where users would like to have views only available in dev mode (monitoring or debugging) so it would be a win win.
In the meantime, after your comments I think that we could try the workaround of not registering these views on start up and trying to use the existing Copilot service initializer to register the views only when copilot is available based on the prefix (or in dev mode not exactly the same).