2 files changed, 60 insertions, 4 deletions

diff --git a/server/src/main/java/com/vaadin/data/Binder.java b/server/src/main/java/com/vaadin/data/Binder.java
index 747983bfa5..cd7b834571 100644
--- a/server/src/main/java/com/vaadin/data/Binder.java
+++ b/server/src/main/java/com/vaadin/data/Binder.java
@@ -226,6 +226,30 @@ public class Binder<BEAN> implements Serializable {
          * @since 8.4
          */
         public Setter<BEAN, TARGET> getSetter();
+
+        /**
+         * Enable or disable asRequired validator.
+         * The validator is enabled by default.
+         *
+         * @see #asRequired(String)
+         * @see #asRequired(ErrorMessageProvider)
+         *
+         * @param asRequiredEnabled
+         *            {@code false} if asRequired validator should
+         *            be disabled, {@code true} otherwise (default)
+         */
+        public void setAsRequiredEnabled(boolean asRequiredEnabled);
+
+        /**
+         * Returns whether asRequired validator is currently enabled or not
+         *
+         * @see #asRequired(String)
+         * @see #asRequired(ErrorMessageProvider)
+         *
+         * @return {@code false} if asRequired validator is disabled
+         *         {@code true} otherwise (default)
+         */
+        public boolean isAsRequiredEnabled();
     }
 
     /**
@@ -781,6 +805,8 @@ public class Binder<BEAN> implements Serializable {
          */
         private Converter<FIELDVALUE, ?> converterValidatorChain;
 
+        private boolean asRequiredSet;
+
         /**
          * Creates a new binding builder associated with the given field.
          * Initializes the builder with the given converter chain and status
@@ -917,8 +943,14 @@ public class Binder<BEAN> implements Serializable {
         public BindingBuilder<BEAN, TARGET> asRequired(
                 Validator<TARGET> customRequiredValidator) {
             checkUnbound();
+            this.asRequiredSet = true;
             field.setRequiredIndicatorVisible(true);
-            return withValidator(customRequiredValidator);
+            return withValidator((value, context) -> {
+                if (!field.isRequiredIndicatorVisible())
+                    return ValidationResult.ok();
+                else
+                    return customRequiredValidator.apply(value, context);
+            });
         }
 
         /**
@@ -1020,12 +1052,15 @@ public class Binder<BEAN> implements Serializable {
          */
         private final Converter<FIELDVALUE, TARGET> converterValidatorChain;
 
+        private boolean asRequiredSet;
+
         public BindingImpl(BindingBuilderImpl<BEAN, FIELDVALUE, TARGET> builder,
                 ValueProvider<BEAN, TARGET> getter,
                 Setter<BEAN, TARGET> setter) {
             this.binder = builder.getBinder();
             this.field = builder.field;
             this.statusHandler = builder.statusHandler;
+            this.asRequiredSet = builder.asRequiredSet;
             converterValidatorChain = ((Converter<FIELDVALUE, TARGET>) builder.converterValidatorChain);
 
             onValueChange = getField()
@@ -1282,6 +1317,24 @@ public class Binder<BEAN> implements Serializable {
         public Setter<BEAN, TARGET> getSetter() {
             return setter;
         }
+
+        @Override
+        public void setAsRequiredEnabled(boolean asRequiredEnabled) {
+            if (!asRequiredSet) {
+                throw new IllegalStateException(
+                 "Unable to toggle asRequired validation since " 
+                         + "asRequired has not been set.");
+            }
+            if (asRequiredEnabled != isAsRequiredEnabled()) {
+                field.setRequiredIndicatorVisible(asRequiredEnabled);
+                        validate();
+            }
+        }
+
+        @Override
+        public boolean isAsRequiredEnabled() {
+            return field.isRequiredIndicatorVisible();
+        }
     }
 
     /**
diff --git a/server/src/test/java/com/vaadin/data/BinderTest.java b/server/src/test/java/com/vaadin/data/BinderTest.java
index 401cc07017..b3fe5a8194 100644
--- a/server/src/test/java/com/vaadin/data/BinderTest.java
+++ b/server/src/test/java/com/vaadin/data/BinderTest.java
@@ -473,13 +473,13 @@ public class BinderTest extends BinderTestBase<Binder<Person>, Person> {
         TextField textField = new TextField();
         assertFalse(textField.isRequiredIndicatorVisible());
 
-        BindingBuilder<Person, String> binding = binder.forField(textField);
+        BindingBuilder<Person, String> bindingBuilder = binder.forField(textField);
         assertFalse(textField.isRequiredIndicatorVisible());
 
-        binding.asRequired("foobar");
+        bindingBuilder.asRequired("foobar");
         assertTrue(textField.isRequiredIndicatorVisible());
 
-        binding.bind(Person::getFirstName, Person::setFirstName);
+        Binding<Person, String> binding = bindingBuilder.bind(Person::getFirstName, Person::setFirstName);
         binder.setBean(item);
         assertNull(textField.getErrorMessage());
 
@@ -491,6 +491,9 @@ public class BinderTest extends BinderTestBase<Binder<Person>, Person> {
         textField.setValue("value");
         assertNull(textField.getErrorMessage());
         assertTrue(textField.isRequiredIndicatorVisible());
+
+        binding.setAsRequiredEnabled(false);
+        assertFalse(textField.isRequiredIndicatorVisible());
     }
 
     @Test