2 files changed, 67 insertions, 0 deletions

diff --git a/server/src/main/java/com/vaadin/data/Binder.java b/server/src/main/java/com/vaadin/data/Binder.java
index 699185dea3..747983bfa5 100644
--- a/server/src/main/java/com/vaadin/data/Binder.java
+++ b/server/src/main/java/com/vaadin/data/Binder.java
@@ -1787,6 +1787,23 @@ public class Binder<BEAN> implements Serializable {
     }
 
     /**
+     * Writes successfully converted and validated changes from the bound fields
+     * to the bean even if there are other fields with non-validated changes.
+     *
+     * @see #writeBean(Object)
+     * @see #writeBeanIfValid(Object)
+     * @see #readBean(Object)
+     * @see #setBean(Object)
+     *
+     * @param bean
+     *            the object to which to write the field values, not
+     *            {@code null}
+     */
+    public void writeBeanAsDraft(BEAN bean) {
+        doWriteDraft(bean, new ArrayList<>(bindings));
+    }
+
+    /**
      * Writes changes from the bound fields to the given bean if all validators
      * (binding and bean level) pass.
      * <p>
@@ -1874,6 +1891,23 @@ public class Binder<BEAN> implements Serializable {
     }
 
     /**
+     * Writes the successfully converted and validated field values into the
+     * given bean.
+     *
+     * @param bean
+     *            the bean to write field values into
+     * @param bindings
+     *            the set of bindings to write to the bean
+     */
+    @SuppressWarnings({ "unchecked" })
+    private void doWriteDraft(BEAN bean, Collection<Binding<BEAN, ?>> bindings) {
+        Objects.requireNonNull(bean, "bean cannot be null");
+
+        bindings.forEach(binding -> ((BindingImpl<BEAN, ?, ?>) binding)
+                    .writeFieldValue(bean));
+    }
+
+    /**
      * Restores the state of the bean from the given values. This method is used
      * together with {@link #getBeanState(Object, Collection)} to provide a way
      * to revert changes in case the bean validation fails after save.
diff --git a/server/src/test/java/com/vaadin/data/BinderTest.java b/server/src/test/java/com/vaadin/data/BinderTest.java
index 3e27cc5f9b..401cc07017 100644
--- a/server/src/test/java/com/vaadin/data/BinderTest.java
+++ b/server/src/test/java/com/vaadin/data/BinderTest.java
@@ -270,6 +270,39 @@ public class BinderTest extends BinderTestBase<Binder<Person>, Person> {
     }
 
     @Test
+    public void save_bound_beanAsDraft() {
+        Binder<Person> binder = new Binder<>();
+        binder.forField(nameField)
+            .withValidator((value,context) -> {
+                if (value.equals("Mike")) return ValidationResult.ok();
+                else return ValidationResult.error("value must be Mike");
+            })
+            .bind(Person::getFirstName, Person::setFirstName);
+        binder.forField(ageField)
+                .withConverter(new StringToIntegerConverter(""))
+                .bind(Person::getAge, Person::setAge);
+
+        Person person = new Person();
+
+        String fieldValue = "John";
+        nameField.setValue(fieldValue);
+
+        int age = 10;
+        ageField.setValue("10");
+
+        person.setFirstName("Mark");
+
+        binder.writeBeanAsDraft(person);
+
+        // name is not written to draft as validation / conversion
+        // does not pass
+        assertNotEquals(fieldValue, person.getFirstName());
+        // age is written to draft even if firstname validation
+        // fails
+        assertEquals(age, person.getAge());
+    }
+
+    @Test
     public void load_bound_fieldValueIsUpdated() {
         binder.bind(nameField, Person::getFirstName, Person::setFirstName);