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

Change-Id: I44498b4b34b2e9732b50abb14e8eb7be01314158

2 files changed, 106 insertions, 6 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;
+    }
+}