polymer template file not found if PolymerTemplate java class is referenced in a spring managed bean

Steps to reproduce:

1. A spring application using Vaadin 14.x
2. A PolymerTemplate component declared as:

@Tag("my-template")
@JsModule("./src/my-template.js")
public class MyTemplate extends PolymerTemplate<MyTemplate.MyTemplateModel> {
......
}

1. A managed bean component containing the PolymerTemplate and the interface used to autowire the bean

public interface SomeInterface  {
    Component asComponent();
}

@SpringComponent
@Scope("prototype")
public class SomeManagedBean extends VerticalLayout implements SomeInterface {

    public SomeManagedBean() {
        add(new MyTemplate());
    }

    @Override
    public Component asComponent() {
        return this;
    }
}

and finally the Route class:

@Route
@PWA(name = "Project Base for Vaadin Flow with Spring", shortName = "Project Base")
public class MainView extends VerticalLayout {

    public MainView(SomeInterface someInterface) {
        this.someInterface = someInterface;
        add(someInterface.asComponent());
    }
}

When running the app and navigating to the MainView route, an exception is thrown complaining:

Couldn't find the definition of the element with tag 'my-template' in any template file declared using '@JsModule' annotations

Minimal project to reproduce the issue skeleton-starter-flow-spring-polymertemplate-spring-managed-bean.zip

[denis-anisimov]

Before the fix it doesn’t matter which mode you are running the app. It always uses byte code scanner.

With the fix dev mode is using full CP scanning, production mode is using byte code scanning. It may be changed with the parameter optimizeBundle.

I don’t follow the releases so I don’t know which release has the fix. Please use the releases page and check which version contains the fix. https://github.com/vaadin/flow/releases

https://github.com/vaadin/flow-and-components-documentation/blob/master/documentation/production/tutorial-production-mode-advanced.asciidoc#goal-parameters-1 (optimizeBundle) https://github.com/vaadin/flow-and-components-documentation/blob/master/documentation/advanced/tutorial-all-vaadin-properties.asciidoc

[denis-anisimov]

Duplicate of #5658 which is fixed.