Binding Items to Components

ComboBox<Status> comboBox = new ComboBox<>();
comboBox.setItemLabelGenerator(Status::getLabel);

// A bean with some fields
final class Person implements Serializable {
    private String name;
    private String email;
    private String title;
    private int yearOfBirth;

    public Person(String name, int yearOfBirth) {
        this.name = name;
        this.yearOfBirth = yearOfBirth;
    }

    public String getName() {
        return name;
    }

    public int getYearOfBirth() {
        return yearOfBirth;
    }

    public String getTitle() {
        return title;
    }

    // other getters and setters
}

// Show such beans in a Grid
Grid<Person> grid = new Grid<>();
grid.addColumn(Person::getName)
    .setHeader("Name");
grid.addColumn(Person::getYearOfBirth)
    .setHeader("Year of birth");

Grid<Person> grid = new Grid<>(Person.class);
grid.setColumns("name", "email", "title");
grid.getColumnByKey("name").setHeader("Name");
grid.getColumnByKey("email").setHeader("Email");
grid.getColumnByKey("title").setHeader("Title");

// Sets items as a collection
List<Person> persons = getPersonService().findAll();
comboBox.setItems(persons);

// Sets items using vararg beans
grid.setItems(
        new Person("George Washington", 1732),
        new Person("John Adams", 1735),
        new Person("Thomas Jefferson", 1743),
        new Person("James Madison", 1751)
);

// Pass all Person objects to a grid from a Spring Data repository object
grid.setItems(personRepository.findAll());

grid.setItems(query -> 1
    getPersonService() 2
            .fetchPersons(
                query.getOffset(), 3
                query.getLimit() 4
            )
            .stream() 5
);

grid.setItems(query -> {
    return repository.findAll( 1
            PageRequest.of(query.getPage(), 2
                           query.getPageSize()) 3
    ).stream(); 4
});

private void exportToCsvFile(Grid<Person> grid)
        throws FileNotFoundException, IOException {
    GridDataView<Person> dataView = grid.getGenericDataView();
    FileOutputStream fout = new FileOutputStream(new File("/tmp/export.csv"));

    dataView.getItems().forEach(person -> {
        try {
            fout.write((person.getFullName() + ", " + person.getEmail() +"\n").getBytes());
        } catch (IOException ex) {
            throw new RuntimeException(ex);
        }
    });
    fout.close();
}

List<Person> allPersons = repo.findAll();
GridListDataView<Person> gridDataView = grid.setItems(allPersons);

Button selectNext = new Button("Next", e -> {
    grid.asSingleSelect().getOptionalValue().ifPresent(p -> {
        gridDataView.getNextItem(p).ifPresent(
                next -> grid.select(next)
        );
    });
});

Person person = new Person();
person.setName("Jorma");
person.setEmail("old@gmail.com");

GridListDataView<Person> gridDataView = grid.setItems(person);

Button modify = new Button("Modify data", e -> {
    person.setEmail("new@gmail.com");

    // The component shows the old email until notified of changes
    gridDataView.refreshItem(person);
});

// The initial data
ArrayList<String> items = new ArrayList<>(Arrays.asList("foo", "bar"));

// Get the data view when binding it to a component
Select<String> select = new Select<>();
SelectListDataView<String> dataView = select.setItems(items);

TextField newItemField = new TextField("Add new item");
Button addNewItem = new Button("Add", e -> {
        // Adding through the data view API mutates the data source
        dataView.addItem(newItemField.getValue());
});
Button remove = new Button("Remove selected", e-> {
        // Same for removal
        dataView.removeItem(select.getValue());
});

// Hook to item count change event
dataView.addItemCountChangeListener(e ->
        Notification.show(" " + e.getItemCount() + " items available"));

// Request the item count directly
Span itemCountSpan = new Span("Total Item Count: " + dataView.getItemCount());

List<Person> allPersons = repo.findAll();
GridListDataView<Person> gridDataView = grid.setItems(allPersons);

// Filter Persons younger 20 years
gridDataView.setFilter(p -> p.getAge() < 20);

// Remove filters completely (undoes the settings done above)
gridDataView.removeFilters();

@SpringComponent
@Scope(ConfigurableBeanFactory.SCOPE_PROTOTYPE)
public class PersonGrid extends Grid<Person> {

    public PersonGrid(@Autowired PersonRepository repo) {
        super(Person.class);

        // Make the lazy binding
        setItems(q -> repo.findAll(
                PageRequest.of(q.getPage(), q.getPageSize())).stream());

        // Make other common/default configuration
        setColumns("name", "email");
    }

}

public static void listItems(Grid<Person> grid, PersonRepository repository) {
    grid.setItems(query -> repository.findAll(
            PageRequest.of(query.getPage(), query.getPageSize())).stream());
}

@SpringComponent
public class PersonDataProvider implements CallbackDataProvider.FetchCallback<Person, Void> {

    @Autowired
    PersonRepository repo;

    @Override
    public Stream<Person> fetch(Query<Person, Void> query) {
        return repo.findAll(PageRequest.of(query.getPage(),
                query.getPageSize())).stream();
    }

}

personGrid.setItems(dataProvider);

class Person {
    private final long id;
    private String name;
    private String phoneNumber;

    public Person(long id, String name, String phoneNumber) {
        this.id = id;
        this.name = name;
        this.phoneNumber = phoneNumber;
    }

    // Getters and setters omitted for brevity

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Person person = (Person) o;
        return id == person.id;
    }

    @Override
    public int hashCode() {
        return Objects.hash(id);
    }
}

@EqualsAndHashCode(onlyExplicitlyIncluded = true)
class Person {
    @EqualsAndHashCode.Include
    private final long id;
    private String name;
    private String phoneNumber;

    public Person(long id, String name, String phoneNumber) {
        this.id = id;
        this.name = name;
        this.phoneNumber = phoneNumber;
    }

    // Getters and setters omitted for brevity
}