Add nullSafeConverter method to Converter interface

flow-data/src/main/java/com/vaadin/flow/data/converter/Converter.java

@@ -173,4 +173,48 @@ public PRESENTATION convertToPresentation(T value,
         };
     }
 
+    /**
+     * Wraps the given {@code converter} with a converter that handles both null
+     * presentation and null model values:
+     * <ul>
+     * <li>If the model value is null, the converter returns null. Otherwise, it
+     * delegates to the wrapped converter.</li>
+     * <li>If the presentation value is null, the converter returns null.
+     * Otherwise, it delegates to the wrapped converter.</li>
+     * </ul>
+     * Example use:
+     * 
+     * <pre>
+     * {@code
+     * Converter<String, LocalDate> converter = Converter
+     *         .nullSafeConverter(Converter.from(LocalDate::parse,
+     *                 LocalDate::toString, Exception::getMessage));
+     * }
+     * </pre>
+     *
+     * @param <P>
+     *            the presentation type
+     * @param <M>
+     *            the model type
+     * @param converter
+     *            the converter to delegate to when the value being converted is
+     *            not null
+     * @return a converter that handles both null presentation and null model
+     *         values
+     */
+    static <P, M> Converter<P, M> nullSafeConverter(Converter<P, M> converter) {
+        return new Converter<P, M>() {
+            @Override
+            public Result<M> convertToModel(P value, ValueContext context) {
+                return value == null ? Result.ok(null)
+                        : converter.convertToModel(value, context);
+            }
+
+            @Override
+            public P convertToPresentation(M value, ValueContext context) {
+                return value == null ? null
+                        : converter.convertToPresentation(value, context);
+            }
+        };
+    }
 }

flow-data/src/test/java/com/vaadin/flow/data/converter/NullSafeConverterTest.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2000-2026 Vaadin Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.vaadin.flow.data.converter;
+
+import org.junit.jupiter.api.Test;
+
+import com.vaadin.flow.data.binder.ValueContext;
+
+import static java.util.Objects.requireNonNull;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNull;
+
+class NullSafeConverterTest {
+
+    record ValueObject(String value) {
+        ValueObject {
+            requireNonNull(value);
+        }
+    }
+
+    private final Converter<String, ValueObject> converter = Converter
+            .nullSafeConverter(Converter.from(ValueObject::new,
+                    ValueObject::value, Exception::getMessage));
+
+    @Test
+    void nullPresentationConvertsToNullModel() {
+        var result = converter.convertToModel(null, new ValueContext());
+        assertFalse(result.isError());
+        assertNull(result.getOrThrow(RuntimeException::new));
+    }
+
+    @Test
+    void nonNullPresentationConvertsToNonNullModel() {
+        var result = converter.convertToModel("hello", new ValueContext());
+        assertFalse(result.isError());
+        assertEquals(new ValueObject("hello"),
+                result.getOrThrow(RuntimeException::new));
+    }
+
+    @Test
+    void nullModelConvertsToNullPresentation() {
+        var result = converter.convertToPresentation(null, new ValueContext());
+        assertNull(result);
+    }
+
+    @Test
+    void nonNullModelConvertsToNonNullPresentation() {
+        var result = converter.convertToPresentation(new ValueObject("hello"),
+                new ValueContext());
+        assertEquals("hello", result);
+    }
+}