'null' value in form fields instead of blank

Vaadin 6 / 7 / 8 Framework UI
1

I implemented a Bean as:
public class SubscriptionBean implements Serializable {
/**
*
*/
private static final long serialVersionUID = 1L;
private String emailId;
private String confirmEmailId;

public String getConfirmEmailId() {
	return confirmEmailId;
}

public void setConfirmEmailId(String confirmEmailId) {
	this.confirmEmailId = confirmEmailId;
}

public String getEmailId() {
	return emailId;
}

public void setEmailId(String emailId) {
	this.emailId = emailId;
}

}

I generated a form based on it. When i see the form it comes up with ‘null’ in the emailId and confirmEmailId fields. So, how to get that blank?

2

TextField.setNullRepresentation(String nullRepresentation)

3

doing ((TextField)subscribeform.getField(“emailId”)).setNullRepresentation(“vik”);
has no effect. It still renders null in the emailId field.

Vik

4

Read this page (
http://vaadin.com/book/-/page/components.form.html
) about forms and FieldFactory. Use a FieldFactory and set the setNullRepresentation in it.


public Field createField(Item item, Object propertyId,
                             Component uiContext) {
    TexTfield text = new TextFiedl();
    text.setNullRepresentation("");
    return text;  
}
5

Btw. why the default null representation is ‘null’? I don’t see any reasonable scenario where text ‘null’ would be better option instead of ‘’ (empty string).

6

Even i agree that there is no reason to default it ‘null’ instead of blank.[quote=Antti Koski]

Btw. why the default null representation is ‘null’? I don’t see any reasonable scenario where text ‘null’ would be better option instead of ‘’ (empty string).
[/quote]

7

So this is the only way to get rid of the ‘null’ coming to it? in others words can’t get the text fields blank using item bean way of generating form?

8

The default is “null” for historical reasons. We wanted it to be symmetric to how System.out.println(“Value is” + null) would be.

9

No. You can use BeanItem just fine:

Form f = new Form();
f.setFormFieldFactory(new FormFieldFactory() {
    public Field createField(Item item, Object propertyId,
            Component uiContext) {
        Field field = DefaultFieldFactory.get().createField(item,
                propertyId, uiContext);
        if (field instanceof TextField) {
            ((TextField) field).setNullRepresentation("");
        }
        return field;
    }
});
f.setItemDataSource(new BeanItem(new Person()));

In practice this is not that much of extra as in most forms you want to set form field factory any case to customize the form behavior.