Commas in Floats

Vaadin 6 / 7 / 8 Framework Data Binding
1

I am using Vaadin 8 and binding my business object attributes to fields in a form. It appears that when a float value greater than 999 is retrieved from a business object and displayed in a text field, commas are added as place separators. For example, it seems that 1023.4 would be displayed as “1,023.4”. Is that the expected behavior? If so, can i prevent it? Thanks. -Dan

2

Can you share a code example where this behavior is reproducible?

3

Hi Olli, Thanks for getting back to me. This code shows the behavior I am asking about. -Dan

package showfloats;

import javax.servlet.annotation.WebServlet;

import com.vaadin.annotations.Theme;
import com.vaadin.annotations.VaadinServletConfiguration;
import com.vaadin.data.Binder;
import com.vaadin.data.converter.StringToFloatConverter;
import com.vaadin.server.VaadinRequest;
import com.vaadin.server.VaadinServlet;
import com.vaadin.ui.TextField;
import com.vaadin.ui.UI;
import com.vaadin.ui.VerticalLayout;

@Theme("mytheme")
public class MyUI extends UI {

	@Override
	protected void init(VaadinRequest vaadinRequest) {
		final VerticalLayout layout = new VerticalLayout();
		Person person = new Person(1234.56f);
		setContent(layout);
		Binder<Person> binder = new Binder<>();
		TextField floatField = new TextField("the float");
		layout.addComponents(floatField);
		binder.forField(floatField).withConverter(new StringToFloatConverter("Must be a float"))
				.bind(Person::getTheFloat, Person::setTheFloat);
		binder.setBean(person);
	}

	@WebServlet(urlPatterns = "/*", name = "MyUIServlet", asyncSupported = true)
	@VaadinServletConfiguration(ui = MyUI.class, productionMode = false)
	public static class MyUIServlet extends VaadinServlet {
	}

	static class Person {
		float theFloat;

		public Person(float f) {
			this.theFloat = f;
		}

		static Float getTheFloat(Person person) {
			return person.theFloat;
		}

		static void setTheFloat(Person person, Float f) {
		}
	};
}
4

What’s happening there is that the StringToFloatConverter uses the current Locale to set up the NumberFormat that’s used to make the float to String conversion. You can create a custom Converter to configure the used format in the getFormat method yourself:

    public static class MyStringToFloatConverter extends StringToFloatConverter {

        public MyStringToFloatConverter(String errorMessage) {
            super(errorMessage);
        }

        @Override
        protected NumberFormat getFormat(Locale locale) {
            NumberFormat instance = NumberFormat.getInstance(locale);
            instance.setGroupingUsed(false);
            return instance;
        }
    }
5

Thanks, Olli. That seems to do just what I wanted. -Dan