java - Vaadin (Flow): Navigating to destination with a shared object

Question

Problem:

I currently have a grid that displays content of type SomeModel. When I click an entry of that Grid I would like to navigate to a view that takes an object as its input to display the entries content.

Implementation:

To achive this behaviour I created a DetailLayout like this:

public DetailLayout extends FlexLayout implements HasUrlParameter<SomeModel>{
    /* skipped some details */
    @Override
    public void setParameter(BeforeEvent event, Host parameter) {
        /* This is where I expected to be able to handle the object */
    }
}

From within the Grid I tried to navigate like this:

addSelectionListener((event) -> {
    event.getFirstSelectedItem().ifPresent(somemodel -> {
        getUI().ifPresent(ui -> {
            ui.navigate(DetailLayout.class, somemodel);
        });
    });
});

But unfortunately this behaviour is not supported by Vaadin even tho its syntax is perfectly fine.

---

Question:

Do you know of another way to pass an object while navigation or did I miss a certain part of the official documentation documentation ?

Thank you in advance

Answer 1

Instead of giving the whole somemodel object as parameter of navigate(), you can pass its id

ui.navigate(DetailLayout.class, somemodel.getId());

And in the DetailLayout.setParameter() you can load the somemodel by its id

@Override
public void setParameter(BeforeEvent beforeEvent, Long someModelId) {
    if(someModelId == null){
        throw new SomeModelNotFoundException("No SomeModel was provided");
    }

    SomeModel someModel = someModelService.findById(someModelId);
    if(someModel == null){
        throw new SomeModelNotFoundException("There is no SomeModel with id "+someModelId);
    }

    // use someModel here as you wish. probably use it for a binder?
}