java如何在Vaadin 8中添加网格过滤器？

Question

瓦丁8号刚出来。在网格中添加过滤器从未出现在他们的文档中，我在stackoverflow中只找到了一个可行的解决方案here

  HeaderCell cell = filterRow.getCell(pid);
                    // Have an input field to use for filter
                    TextField filterField = new TextField();
                    filterField.setColumns(0);
                    filterField.setHeight("23");



                    // Update filter When the filter input is changed
                    filterField.addTextChangeListener(change -> {
                        // Can't modify filters so need to replace
                        b.removeContainerFilters(pid);

                        // (Re)create the filter if necessary
                        if (! change.getText().isEmpty())
                            b.addContainerFilter(
                                new SimpleStringFilter(pid,
                                    change.getText(), true, false));
                    });
                    cell.setComponent(filterField);

但自从更新后，这个解决方案不再有效，因为SimpleStringFilter在新网格中不再可用，BeanItemContainer不再被识别，只允许setItems（）填充网格数据

有人能帮我更新Vaadin 8的代码吗

Answer 1

可以为Vaadin 8网格添加过滤

假设我们已经将人模型定义为：

final class Person {

    private String name;

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

    public String getName() {
        return name;
    }

}

我们的网格实现如下所示：

final class PersonGrid extends Grid<Person> {

    public PersonGrid() {
        List<Person> persons = new ArrayList<>();
        persons.add(new Person("foo"));
        persons.add(new Person("bar"));
        persons.add(new Person("foobar"));

        addColumn(Person::getName).setCaption("Name");

        setItems(persons);
    }

}

现在，我们可以创建一个带有文本字段的布局，它将成为我们的过滤器：

final class FilteredGridLayout extends VerticalLayout {

    private final PersonGrid personGrid;
    private final TextField nameFilter;

    public FilteredGridLayout() {
        nameFilter = new TextField();
        nameFilter.setPlaceholder("Name...");
        nameFilter.addValueChangeListener(this::onNameFilterTextChange);
        addComponent(nameFilter);

        personGrid = new PersonGrid();
        addComponentsAndExpand(personGrid);
    }

    private void onNameFilterTextChange(HasValue.ValueChangeEvent<String> event) {
        ListDataProvider<Person> dataProvider = (ListDataProvider<Person>) personGrid.getDataProvider();
        dataProvider.setFilter(Person::getName, s -> caseInsensitiveContains(s, event.getValue()));
    }

    private Boolean caseInsensitiveContains(String where, String what) {
        return where.toLowerCase().contains(what.toLowerCase());
    }

}

结果如下所示：

对于空输入，结果是：foo、bar和foobar

对于foo结果是：foo和foo条

对于bar，结果是：bar和foobar

对于foobar，结果是：foobar