BeanFieldGroup with ComboBox?

java, vaadin7

Solution

Thats a good question! After some investigation I found the following solution:

You have to create your custom FieldGroupFieldFactory (why see below):

binder.setFieldFactory(new DefaultFieldGroupFieldFactory() {

    @Override
    public <T extends Field> T createField(Class<?> type, Class<T> fieldType) {

        if (type.isAssignableFrom(String.class) && fieldType.isAssignableFrom(ComboBox.class)) {
            return (T) new ComboBox();
        }

        return super.createField(type, fieldType);
    }

});

The reason why:

If you have a look at the vaadin source code of DefaultFieldGroupFieldFactory.java you will see that in the end a `ComboBox` will only be created IF you provide an Enum as "property data source". You provide a String so the `DefaultFieldGroupFieldFactory` wants to create a `TextField`. But you provided a `ComboBox`. In the end there is an Exception thrown.

With your own Factory it will work. Don't forget to `setItemDataSource(bean)` and `commit()` your binder to actually write the gender to the bean.

Problem

I'm trying create a ComboBox component using BeanFieldGroup in my application, but still can't do this works. I tried create a combobox first and after add this combobox in buildAndBind but doesn't work also. I'm trying this: ``` /** person's bean */ @Entity public class Person{ @Id @GeneratedValue private Integer id; @NotNull @NotEmpty @Size(min=5, max=50, message="insert first name") private String firstName; @NotNull @NotEmpty @Email private String email; //female or male private String gender; //get and set } /** app */ public class PersonView extends CustomComponent{ private final BeanFieldGroup<Person> binder = new BeanFieldGroup<Person>(Person.class); private Person bean = new Person(); private ComboBox gender; public PersonView(){ VerticalLayout vLayout = new VerticalLayout(); Field<?> field = null; field = binder.buildAndBind("Gender", "gender", ComboBox.class); gender = (ComboBox)binder.getField("gender"); gender.addItem("Male"); gender.addItem("Female"); vLayout.addComponent(gender); } } ``` Exception: ``` /** exception /* Caused by: com.vaadin.data.fieldgroup.FieldGroup$BindException: Unable to build a field of type com.vaadin.ui.ComboBox for editing java.lang.String at com.vaadin.data.fieldgroup.FieldGroup.build(FieldGroup.java:1067) at com.vaadin.data.fieldgroup.FieldGroup.buildAndBind(FieldGroup.java:1039) at br.ind.ibg.views.CurriculumView.buildLayout(CurriculumView.java:50) at br.ind.ibg.views.CurriculumView.<init>(CurriculumView.java:32) at br.ind.ibg.views.LoginView.buttonClick(LoginView.java:84) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at com.vaadin.event.ListenerMethod.receiveEvent(ListenerMethod.java:508) ... 37 more ``` How I do this ?

Original source