@Id mapped Tabs should be able to selected @Id mapped Tab

[Artur-]

Given main-view.js

import { PolymerElement, html } from "@polymer/polymer";

class MainView extends PolymerElement {
  static get template() {
    return html`
      <vaadin-button id="button">Go</vaadin-button>
      <vaadin-tabs id="tabs">
        <vaadin-tab>First</vaadin-tab>
        <vaadin-tab id="secondTab">Second</vaadin-tab>
        <vaadin-tab>Third</vaadin-tab>
      </vaadin-tabs>
    `;
  }
}

customElements.define("main-view", MainView);

and MainView.java

@Route
@JsModule("./main-view.js")
@Tag("main-view")
public class MainView extends PolymerTemplate<TemplateModel> {

    @Id
    private Button button;
    @Id
    private Tabs tabs;
    @Id
    private Tab secondTab;

    public MainView() {
        button.addClickListener(e -> {
            tabs.setSelectedTab(secondTab);
        });
    }

}

You would expect a button click would select the second tab.

Currently an exception is printed instead

java.lang.IllegalArgumentException: Tab to select must be a child: Tab{}
	at com.vaadin.flow.component.tabs.Tabs.setSelectedTab(Tabs.java:381) ~[vaadin-tabs-flow-2.0.4.jar:na]
	at com.example.app.MainView.lambda$0(MainView.java:38) ~[classes/:na]

[Legioth]

From an implementation point of view, this would at the very least mean that when one @Id element is the child of another @Id element, then Flow should set up a parent-child relationship between them.

It may also be necessary to define elements (but not component instances) for the siblings so that the relative position of the child can be determined.

[caalador]

Also note the issue vaadin/vaadin-tabs-flow#67

[pleku]

As said in vaadin/vaadin-tabs-flow#67 (comment) we were not going to do anything about this and would simply not recommend using @Id mapping with Tabs.

My bet is that this is quite big task to do, and I'm not sure if this is just about what @Legioth said about the parent-child relationship but also would need changes to the Tabs component.

So the question would be: do we really need to fix this ? How did you come up with this use case @Artur- ?