如何使用Scala驗證Vaadin中表中的字段

Question

如何驗證vaadin表中的字段？ 例如帶有正則表達式的年份字段：

   val persons: BeanContainer[Int, Person] =
   new BeanContainer[Int, Person] classOf[Person])

   persons.setBeanIdProperty("id")
   persons.addBean(new Person("Thomas", "Mann", 1929, 123123))
   persons.addBean(new Person("W. B.", "Yeats", 1923, 643454))
   persons.addBean(new Person("Günter", "Grass", 1999, 743523))

   // create table
   val table: Table = new Table("Nobel Prize for Literature", persons)

   table.setVisibleColumns(Array("id", "firstName", "lastName", "year"))

   table.setColumnHeader("lastName", "last name")
   table.setColumnHeader("firstName", "first name")
   table.setColumnHeader("year", "year")

   // create a validator 
   val yearValidator = new RegexpValidator("[1-2][0-9]{3}", 
                                       "year must be a number 1000-2999.");

   // TODO check the year field!
   table.addValidator(yearValidator)

我創建了一個Regex Validator，但是如何將驗證器設置為正確的字段？

Answer 1

您必須使用字段工廠攔截字段的創建，並在那里添加驗證器：

    table.setTableFieldFactory(new DefaultFieldFactory() {
        @Override
        public Field createField(Item item, Object propertyId, Component uiContext) {
            Field field = super.createField(item, propertyId, uiContext);
            if ("year".equals(propertyId)) {
                field.addValidator(new RegexpValidator("[1-2][0-9]{3}", 
                                   "year must be a number 1000-2999.");
            }
            return field;
        }
    });

（Java，而不是Scala，但將它轉換為scala應該很簡單）。