Multiple validator instances added to field when using JSR 303 validation

Vaadin 6 / 7 / 8
1

Hello,
I’m using Vaadin 7.0.0.beta11. I have a Form with BeanFieldGroup. It seems that validator instances are added to field every time fieldGroup.setItemDataSource() is called.

I’m using setItemDataSource() calls to change data bound to a form. The use case is that I have table that displays some bean data, and when I click on table row, all bean data should appear in a form for edit. So, in table’s itemClick() handler I do: fieldGroup.setItemDataSource(event.getItem()); The problem is, that for every click, another validator gets added for every field in the form.

I have created simple example to reproduce:


public class HelloWorld extends UI {
	private static final long serialVersionUID = 1L;

	@Override
	protected void init(VaadinRequest request) {

		VerticalLayout content = new VerticalLayout();
		setContent(content);

		final BeanFieldGroup<TestBean> fieldGroup = new BeanFieldGroup<TestBean>(TestBean.class);

		final FormLayout form = new FormLayout();
		form.addComponent(fieldGroup.buildAndBind("Name", "name"));
		content.addComponent(form);

		fieldGroup.setItemDataSource(new TestBean());
		fieldGroup.setItemDataSource(new TestBean());
	}

	public static class TestBean {

		@Size(min = 0, max = 5)
		private String name = "";

		public String getName() {
			return name;
		}
		public void setName(String name) {
			this.name = name;
		}
	}
}

The two calls to “fieldGroup.setItemDataSource(new TestBean());” will result in 2 validators added to form item, and 2 validator messages will be displayed on validation error.
Am I doing something wrong here?

Thanks.

2

Hi,
it is the protected method FieldGroup.configureField() overridden in BeanFieldGroup that will add the BeanValidators anew to the fields each time the item data source is changed. This appears to me as a flaw in the API since I too would expect setItemDataSource() to only change the data source and not the configuration of the field group. There is a workaround though that you could try: remove all validators from the fields before calling setItemDataSource():

for (Field field : fieldGroup.getFields()) {
    field.removeAllValidators();
}

fieldGroup.setItemDataSource(...);

It’s not particularly pretty, but it should work.

3

Thanks for your answer, I too came up with the solution of manually cleaning validators before calling fieldGroup.setItemDataSource(), but your code is more simple, and works :slight_smile:

But should I raise ticket for this? Doesn’t seems like this should be expected behavior…?

4

Yes, I think this should be reported. From my point of view, this seems like a flaw in the implementation.

5

I have the same problem. Have you already reported the bug?

6


New ticket opened