scala - 如何使用 Scala 验证 Vaadin 中的表中的字段

Question

如何验证 vaadin 表中的字段？例如带有正则表达式的年份字段:

   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)

我创建了一个正则表达式验证器，但如何将验证器设置到正确的字段？

Answer 1

您必须使用字段工厂拦截字段的创建并在那里添加验证器:

    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，不是 Scala，但将其转换为 Scala 应该很简单)。