Java Code Examples for com.vaadin.flow.component.Component#from()

@Test
public void collectBeforeNavigationObserversFromUI() throws Exception {
    UI ui = UI.getCurrent();
    Element node = ui.getElement();
    node.appendChild(new Element("main"), new Element("menu"));
    Element nested = new Element("nested");
    nested.appendChild(new Element("nested-child"),
            new Element("nested-child-2"));

    node.appendChild(nested);
    Component.from(nested, LeaveObserver.class);

    List<BeforeLeaveObserver> beforeNavigationObservers = EventUtil
            .collectBeforeLeaveObservers(ui);

    Assert.assertEquals("Wrong amount of listener instances found", 1,
            beforeNavigationObservers.size());
}
 

@Test
public void collectBeforeNavigationObserversFromUI_elementHasVirtualChildren()
        throws Exception {
    UI ui = UI.getCurrent();
    Element node = ui.getElement();
    node.appendChild(new Element("main"), new Element("menu"));
    Element nested = new Element("nested");
    nested.appendVirtualChild(new Element("nested-child"),
            new Element("nested-child-2"));

    node.appendChild(nested);

    node.getStateProvider().appendVirtualChild(node.getNode(),
            new Element("attached-by-id"), NodeProperties.INJECT_BY_ID,
            "id");

    Component.from(nested, LeaveObserver.class);

    List<BeforeLeaveObserver> beforeNavigationObservers = EventUtil
            .collectBeforeLeaveObservers(ui);

    Assert.assertEquals("Wrong amount of listener instances found", 1,
            beforeNavigationObservers.size());
}
 

@Test
public void collectAfterNavigationObservers() {
    UI ui = UI.getCurrent();

    Element menu = new Element("menu");
    menu.appendChild(new AfterObserver().getElement());

    Element node = ui.getElement();
    node.appendChild(new Element("main"), menu);
    Element nested = new Element("nested");
    nested.appendChild(new Element("nested-child"),
            new Element("nested-child-2"));

    node.appendChild(nested);
    Component.from(nested, AfterObserver.class);

    List<AfterNavigationObserver> beforeNavigationObservers = EventUtil
            .collectAfterNavigationObservers(ui);

    Assert.assertEquals("Wrong amount of listener instances found", 2,
            beforeNavigationObservers.size());
}
 

@Test
public void getImplementingComponents() throws Exception {
    Element node = new Element("root");
    node.appendChild(new Element("main"), new Element("menu"));
    Element nested = new Element("nested");
    nested.appendChild(new Element("nested-child"),
            new Element("nested-child-2"));

    node.appendChild(nested);
    Component.from(nested, EnterObserver.class);

    List<Element> elements = new ArrayList<>();

    EventUtil.inspectHierarchy(node, elements, element -> true);

    List<BeforeEnterObserver> listenerComponents = EventUtil
            .getImplementingComponents(elements.stream(),
                    BeforeEnterObserver.class)
            .collect(Collectors.toList());

    Assert.assertEquals("Wrong amount of listener instances found", 1,
            listenerComponents.size());
}
 

@Test
public void getImplementingComponents_elementHasVirtualChildren()
        throws Exception {
    Element node = new Element("root");
    node.appendChild(new Element("main"), new Element("menu"));
    Element nested = new Element("nested");
    nested.appendChild(new Element("nested-child"),
            new Element("nested-child-2"));

    node.getStateProvider().appendVirtualChild(node.getNode(), nested,
            NodeProperties.TEMPLATE_IN_TEMPLATE, "");
    Component.from(nested, EnterObserver.class);

    List<Element> elements = new ArrayList<>();

    EventUtil.inspectHierarchy(node, elements, element -> true);

    List<BeforeEnterObserver> listenerComponents = EventUtil
            .getImplementingComponents(elements.stream(),
                    BeforeEnterObserver.class)
            .collect(Collectors.toList());

    Assert.assertEquals("Wrong amount of listener instances found", 1,
            listenerComponents.size());
}
 

@Test
public void collectLocaleChangeObserverFromElement() throws Exception {
    Element node = new Element("root");
    node.appendChild(new Element("main"), new Element("menu"));
    Element nested = new Element("nested-locale");
    nested.appendChild(new Element("nested-child"),
            new Element("nested-child-2"));

    node.appendChild(nested);
    Component.from(nested, Locale.class);

    List<LocaleChangeObserver> beforeNavigationObservers = EventUtil
            .collectLocaleChangeObservers(node);

    Assert.assertEquals("Wrong amount of listener instances found", 1,
            beforeNavigationObservers.size());
}
 

@Test
public void collectLocaleChangeObserverFromElement_elementHasVirtualChildren()
        throws Exception {
    Element node = new Element("root");
    node.appendChild(new Element("main"), new Element("menu"));
    node.appendVirtualChild(new Element("main-virtual"),
            new Element("menu-virtual"));
    Element nested = new Element("nested-locale");
    nested.appendVirtualChild(new Element("nested-child"),
            new Element("nested-child-2"));

    node.appendVirtualChild(nested);
    Component.from(nested, Locale.class);

    List<LocaleChangeObserver> beforeNavigationObservers = EventUtil
            .collectLocaleChangeObservers(node);

    Assert.assertEquals("Wrong amount of listener instances found", 1,
            beforeNavigationObservers.size());
}
 

@SuppressWarnings("unchecked")
private void injectTemplateElement(Element element, Field field,
        Consumer<Element> beforeComponentInject) {
    Class<?> fieldType = field.getType();
    if (Component.class.isAssignableFrom(fieldType)) {
        beforeComponentInject.accept(element);
        Component component;

        Optional<Component> wrappedComponent = element.getComponent();
        if (wrappedComponent.isPresent()) {
            component = wrappedComponent.get();
        } else {
            Class<? extends Component> componentType = (Class<? extends Component>) fieldType;
            component = Component.from(element, componentType);
        }

        ReflectTools.setJavaFieldValue(template, field, component);
    } else if (Element.class.isAssignableFrom(fieldType)) {
        ReflectTools.setJavaFieldValue(template, field, element);
    } else {
        String msg = String.format(
                "The field '%s' in '%s' has an @'%s' "
                        + "annotation but the field type '%s' "
                        + "does not extend neither '%s' nor '%s'",
                field.getName(), getContainerClass().getName(),
                Id.class.getSimpleName(), fieldType.getName(),
                Component.class.getSimpleName(),
                Element.class.getSimpleName());

        throw new IllegalArgumentException(msg);
    }
}
 

private void handleLabel(Element label) {
    attachedLabel = Component.from(label, Label.class);
    attachedLabel.setText("Client side label");
    attachedLabel.setId("label");

    add(AbstractDivView.createButton("Attach the already attached label",
            "attach-populated-label",
            event -> getElement().getStateProvider().attachExistingElement(
                    getElement().getNode(), "label", null,
                    this::handleAttachedLabel)));

    add(createButton("Remove myself on the server side", "remove-self",
            event -> event.getSource().getElement().removeFromParent()));
}
 

private void handleHeader(Element header) {
    H1 lbl = Component.from(header, H1.class);
    lbl.setText("Client side header");
    lbl.setId("header");
}
 

private void handleLabelInShadow(Element label) {
    Label lbl = Component.from(label, Label.class);
    lbl.setText("Client side label in shadow root");
    lbl.setId("label-in-shadow");
}