fix: Add missing refreshAll method to data view

flow-data/src/main/java/com/vaadin/flow/data/provider/AbstractDataView.java

@@ -131,6 +131,11 @@ public void refreshItem(T item) {
         //@formatter:on
     }
 
+    @Override
+    public void refreshAll() {
+        dataProviderSupplier.get().refreshAll();
+    }
+
     @Override
     public void setIdentifierProvider(
             IdentifierProvider<T> identifierProvider) {

flow-data/src/main/java/com/vaadin/flow/data/provider/DataView.java

@@ -73,6 +73,11 @@ public interface DataView<T> extends Serializable {
      */
     void refreshItem(T item);
 
+    /**
+     * Notifies the component that all the items should be refreshed.
+     */
+    void refreshAll();
+
     /**
      * Add an item count change listener that is fired when the item count
      * changes. This can happen for instance when filtering the items.

flow-data/src/test/java/com/vaadin/flow/data/provider/AbstractDataViewTest.java

@@ -20,6 +20,7 @@
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.stream.Stream;
 
 import com.vaadin.flow.component.Component;
@@ -88,6 +89,19 @@ public void addItemCountChangeListener_fireEvent_listenerNotified() {
         Assert.assertEquals(10, fired.get());
     }
 
+    @Test
+    public void refreshAll_listenersNotified() {
+        AtomicReference<DataChangeEvent<Item>> refreshAllEvent =
+                new AtomicReference<>();
+        dataProvider.addDataProviderListener(event -> {
+            Assert.assertNull(refreshAllEvent.get());
+            refreshAllEvent.set(event);
+        });
+        dataView.refreshAll();
+        Assert.assertNotNull(refreshAllEvent.get());
+        Assert.assertEquals(dataProvider, refreshAllEvent.get().getSource());
+    }
+
     /**
      * setIdentifierProvider is tested in AbstractListDataView since it
      * has the container(T item) method.

flow-data/src/test/java/com/vaadin/flow/data/provider/hierarchy/HasHierarchicalDataProviderTest.java

@@ -120,6 +120,11 @@ public TestListDataView addItemBefore(String item, String before) {
         public void refreshItem(String item) {
         }
 
+        @Override
+        public void refreshAll() {
+
+        }
+
         @Override
         public TestListDataView addItems(Collection<String> items) {
             return null;