Implement Binder.saveIfValid and fix Binder.save to throw exception

Change-Id: I44498b4b34b2e9732b50abb14e8eb7be01314158

3 files changed, 157 insertions, 9 deletions

diff --git a/server/src/main/java/com/vaadin/data/Binder.java b/server/src/main/java/com/vaadin/data/Binder.java
index 34027c1f77..094afd2bd8 100644
--- a/server/src/main/java/com/vaadin/data/Binder.java
+++ b/server/src/main/java/com/vaadin/data/Binder.java
@@ -738,18 +738,65 @@ public class Binder<BEAN> implements Serializable {
     }
 
     /**
-     * Saves changes from the bound fields to the edited bean. If any value
-     * fails validation, no values are saved and an {@code BindingException} is
-     * thrown.
+     * Saves changes from the bound fields to the given bean if all validators
+     * pass.
+     * <p>
+     * If any field binding validator fails, no values are saved and an
+     * exception is thrown.
+     *
+     * @see #saveIfValid(Object)
+     * @see #load(Object)
+     * @see #bind(Object)
      *
      * @param bean
      *            the object to which to save the field values, not null
-     * @throws BindingException
+     * @throws ValidationException
      *             if some of the bound field values fail to validate
      */
-    public void save(BEAN bean) {
+    public void save(BEAN bean) throws ValidationException {
+        List<ValidationError<?>> errors = doSaveIfValid(bean);
+        if (!errors.isEmpty()) {
+            throw new ValidationException(errors);
+        }
+    }
+
+    /**
+     * Saves changes from the bound fields to the given bean if all validators
+     * pass.
+     * <p>
+     * If any field binding validator fails, no values are saved and
+     * <code>false</code> is returned.
+     *
+     * @see #saveIfValid(Object)
+     * @see #load(Object)
+     * @see #bind(Object)
+     *
+     * @param bean
+     *            the object to which to save the field values, not null
+     * @return {@code true} if there was no validation errors and the bean was
+     *         updated, {@code false} otherwise
+     */
+    public boolean saveIfValid(BEAN bean) {
+        return doSaveIfValid(bean).isEmpty();
+    }
+
+    /**
+     * Saves the field values into the given bean if all field level validators
+     * pass.
+     *
+     * @param bean
+     *            the bean to save field values into
+     * @return a list of field validation errors
+     */
+    private List<ValidationError<?>> doSaveIfValid(BEAN bean) {
         Objects.requireNonNull(bean, "bean cannot be null");
-        bindings.forEach(binding -> binding.storeFieldValue(bean));
+        // First run fields level validation
+        List<ValidationError<?>> errors = validate();
+        // If no validation errors then update bean
+        if (errors.isEmpty()) {
+            bindings.forEach(binding -> binding.storeFieldValue(bean));
+        }
+        return errors;
     }
 
     /**
diff --git a/server/src/main/java/com/vaadin/data/ValidationException.java b/server/src/main/java/com/vaadin/data/ValidationException.java
new file mode 100644
index 0000000000..41017a8393
--- /dev/null
+++ b/server/src/main/java/com/vaadin/data/ValidationException.java
@@ -0,0 +1,53 @@
+/*
+ * Copyright 2000-2016 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.data;
+
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * Indicates validation errors in a {@link Binder} when save is requested.
+ * 
+ * @see Binder#save(Object)
+ * 
+ * @author Vaadin Ltd
+ * @since 8.0
+ *
+ */
+public class ValidationException extends Exception {
+
+    private final List<ValidationError<?>> errors;
+
+    /**
+     * Constructs a new exception with validation {@code errors} list.
+     * 
+     * @param errors
+     *            validation errors list
+     */
+    public ValidationException(List<ValidationError<?>> errors) {
+        super("Validation has failed for some fields");
+        this.errors = Collections.unmodifiableList(errors);
+    }
+
+    /**
+     * Returns the validation errors list which caused the exception.
+     * 
+     * @return validation errors list
+     */
+    public List<ValidationError<?>> getValidationError() {
+        return errors;
+    }
+}
diff --git a/server/src/test/java/com/vaadin/data/BinderTest.java b/server/src/test/java/com/vaadin/data/BinderTest.java
index 331d4d30de..be408d6142 100644
--- a/server/src/test/java/com/vaadin/data/BinderTest.java
+++ b/server/src/test/java/com/vaadin/data/BinderTest.java
@@ -15,6 +15,7 @@ import org.junit.Test;
 
 import com.vaadin.data.Binder.Binding;
 import com.vaadin.data.util.converter.Converter;
+import com.vaadin.data.validator.NotEmptyValidator;
 import com.vaadin.server.AbstractErrorMessage;
 import com.vaadin.server.ErrorMessage;
 import com.vaadin.server.UserError;
@@ -150,7 +151,7 @@ public class BinderTest {
     }
 
     @Test
-    public void save_unbound_noChanges() {
+    public void save_unbound_noChanges() throws ValidationException {
         Binder<Person> binder = new Binder<>();
         Person person = new Person();
 
@@ -163,7 +164,7 @@ public class BinderTest {
     }
 
     @Test
-    public void save_bound_beanIsUpdated() {
+    public void save_bound_beanIsUpdated() throws ValidationException {
         Binder<Person> binder = new Binder<>();
         binder.bind(nameField, Person::getFirstName, Person::setFirstName);
 
@@ -180,7 +181,7 @@ public class BinderTest {
     }
 
     @Test
-    public void save_null_beanIsUpdated() {
+    public void save_null_beanIsUpdated() throws ValidationException {
         Binder<Person> binder = new Binder<>();
         binder.forField(nameField).withConverter(fieldValue -> {
             if ("null".equals(fieldValue)) {
@@ -202,6 +203,53 @@ public class BinderTest {
         Assert.assertNull(person.getFirstName());
     }
 
+    @Test(expected = ValidationException.class)
+    public void save_fieldValidationErrors() throws ValidationException {
+        Binder<Person> binder = new Binder<>();
+        String msg = "foo";
+        binder.forField(nameField).withValidator(new NotEmptyValidator<>(msg))
+                .bind(Person::getFirstName, Person::setFirstName);
+
+        Person person = new Person();
+        String firstName = "foo";
+        person.setFirstName(firstName);
+        nameField.setValue("");
+        try {
+            binder.save(person);
+        } finally {
+            Assert.assertEquals(firstName, person.getFirstName());
+        }
+    }
+
+    @Test
+    public void saveIfValid_fieldValidationErrors() {
+        Binder<Person> binder = new Binder<>();
+        String msg = "foo";
+        binder.forField(nameField).withValidator(new NotEmptyValidator<>(msg))
+                .bind(Person::getFirstName, Person::setFirstName);
+
+        Person person = new Person();
+        person.setFirstName("foo");
+        nameField.setValue("");
+        Assert.assertFalse(binder.saveIfValid(person));
+        Assert.assertEquals("foo", person.getFirstName());
+    }
+
+    @Test
+    public void saveIfValid_noValidationErrors() {
+        Binder<Person> binder = new Binder<>();
+        String msg = "foo";
+        binder.forField(nameField).withValidator(new NotEmptyValidator<>(msg))
+                .bind(Person::getFirstName, Person::setFirstName);
+
+        Person person = new Person();
+        person.setFirstName("foo");
+        nameField.setValue("bar");
+
+        Assert.assertTrue(binder.saveIfValid(person));
+        Assert.assertEquals("bar", person.getFirstName());
+    }
+
     @Test
     public void load_bound_fieldValueIsUpdated() {
         Binder<Person> binder = new Binder<>();