Better default for nullRepresentation (#13221, #12877)

Change-Id: Ia4662c79b20ee699b3a9741ffa24c4de6645b775

5 files changed, 162 insertions, 2 deletions

diff --git a/server/src/main/java/com/vaadin/server/DefaultDeploymentConfiguration.java b/server/src/main/java/com/vaadin/server/DefaultDeploymentConfiguration.java
index 1f22a9e33d..677be2e31b 100644
--- a/server/src/main/java/com/vaadin/server/DefaultDeploymentConfiguration.java
+++ b/server/src/main/java/com/vaadin/server/DefaultDeploymentConfiguration.java
@@ -21,6 +21,7 @@ import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import com.vaadin.shared.communication.PushMode;
+import com.vaadin.ui.AbstractTextField;
 
 /**
  * The default implementation of {@link DeploymentConfiguration} based on a base
@@ -97,6 +98,17 @@ public class DefaultDeploymentConfiguration extends
         checkLegacyPropertyToString();
         checkSyncIdCheck();
         checkSendUrlsAsParameters();
+        checkNullRepresentationLegacyMode();
+    }
+
+    private void checkNullRepresentationLegacyMode() {
+        final boolean legacyMode = getApplicationOrSystemProperty(
+                "com.vaadin.nullrepresentationlegacymode",
+                Boolean.toString(false)).equals("true");
+        if (legacyMode) {
+            AbstractTextField.setNullRepresentationDefault("null");
+        }
+
     }
 
     private void checkLegacyPropertyToString() {
diff --git a/server/src/main/java/com/vaadin/ui/AbstractTextField.java b/server/src/main/java/com/vaadin/ui/AbstractTextField.java
index 5fbe60937a..ce1d6f638d 100644
--- a/server/src/main/java/com/vaadin/ui/AbstractTextField.java
+++ b/server/src/main/java/com/vaadin/ui/AbstractTextField.java
@@ -41,10 +41,13 @@ import com.vaadin.ui.declarative.DesignContext;
 public abstract class AbstractTextField extends AbstractField<String> implements
         BlurNotifier, FocusNotifier, TextChangeNotifier, LegacyComponent {
 
+    private static String nullRepresentationDefault = "";
+
     /**
      * Null representation.
      */
-    private String nullRepresentation = "null";
+    private String nullRepresentation = nullRepresentationDefault;
+
     /**
      * Is setting to null from non-null value allowed by setting with null
      * representation .
@@ -810,4 +813,36 @@ public abstract class AbstractTextField extends AbstractField<String> implements
                 getMaxLength(), def.getMaxLength(), Integer.class);
     }
 
+    /**
+     * @since 7.6
+     * @return the default value used for nullRepresentation
+     */
+    public static String getNullRepresentationDefault() {
+        return nullRepresentationDefault;
+    }
+
+    /**
+     * A static helper to define the default value used for nullRepresentation.
+     * <p>
+     * In 7.6 the infamous default value "null" for
+     * AbstractTextField.nullRepresentation was changed to "", which may cause
+     * unexpected issues in certain applications that don't tackle null values.
+     * If there are several places in your application that depend on the old
+     * default, this method can be used to put new AbstractTextField instances
+     * into backwards compatibility mode by defining the default value as
+     * "null". The "legacy mode" can also be forced by setting system property
+     * "com.vaadin.nullrepresentationlegacymode" (before AbstractTextField class
+     * is loaded by your class loader).
+     * 
+     * @since 7.6
+     * @param nullRepresentationString
+     *            the value that will be used as a default for
+     *            {@link AbstractTextField#getNullRepresentation()} in new
+     *            instances
+     */
+    public static void setNullRepresentationDefault(
+            String nullRepresentationString) {
+        AbstractTextField.nullRepresentationDefault = nullRepresentationString;
+    }
+
 }
diff --git a/uitest/src/main/java/com/vaadin/tests/components/textfield/NullRepresentationLegacyMode.java b/uitest/src/main/java/com/vaadin/tests/components/textfield/NullRepresentationLegacyMode.java
new file mode 100644
index 0000000000..ab0bc6e534
--- /dev/null
+++ b/uitest/src/main/java/com/vaadin/tests/components/textfield/NullRepresentationLegacyMode.java
@@ -0,0 +1,84 @@
+/*
+ * Copyright 2000-2014 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.tests.components.textfield;
+
+import com.vaadin.annotations.Theme;
+import com.vaadin.data.fieldgroup.BeanFieldGroup;
+import com.vaadin.server.VaadinRequest;
+import com.vaadin.tests.components.AbstractTestUI;
+import com.vaadin.ui.AbstractTextField;
+import com.vaadin.ui.TextField;
+import com.vaadin.ui.VerticalLayout;
+
+@SuppressWarnings("serial")
+@Theme("valo")
+public class NullRepresentationLegacyMode extends AbstractTestUI {
+
+    public static class Entity {
+
+        private String value;
+
+        public String getValue() {
+            return value;
+        }
+
+        public void setValue(String value) {
+            this.value = value;
+        }
+
+    }
+
+    public static class Form extends VerticalLayout {
+        TextField value = new TextField();
+
+        public Form() {
+            setMargin(true);
+            setSpacing(true);
+            addComponent(value);
+        }
+    }
+
+    @Override
+    protected void setup(VaadinRequest request) {
+        Form formWithoutNulls = new Form();
+        formWithoutNulls.setCaption("No 'null's here please");
+        formWithoutNulls.setId("without");
+        BeanFieldGroup.bindFieldsUnbuffered(new Entity(), formWithoutNulls);
+
+        // Use the legacy default
+        AbstractTextField.setNullRepresentationDefault("null");
+
+        Form formWithNulls = new Form();
+        formWithNulls.setCaption("'null's please");
+        formWithNulls.setId("with");
+        BeanFieldGroup.bindFieldsUnbuffered(new Entity(), formWithNulls);
+        AbstractTextField.setNullRepresentationDefault("");
+
+        addComponents(formWithoutNulls, formWithNulls);
+    }
+
+    @Override
+    protected String getTestDescription() {
+        return "Text field must not truncate underscores in modal dialogs.";
+    }
+
+    @Override
+    protected Integer getTicketNumber() {
+        return 12974;
+    }
+
+}
diff --git a/uitest/src/main/java/com/vaadin/tests/fieldgroup/MultipleValidationErrors.java b/uitest/src/main/java/com/vaadin/tests/fieldgroup/MultipleValidationErrors.java
index 58f2292f84..f09b32d5c7 100644
--- a/uitest/src/main/java/com/vaadin/tests/fieldgroup/MultipleValidationErrors.java
+++ b/uitest/src/main/java/com/vaadin/tests/fieldgroup/MultipleValidationErrors.java
@@ -1,5 +1,7 @@
 package com.vaadin.tests.fieldgroup;
 
+import org.apache.commons.lang.StringEscapeUtils;
+
 import com.vaadin.data.Validator;
 import com.vaadin.data.fieldgroup.FieldGroup;
 import com.vaadin.data.util.BeanItem;
@@ -7,10 +9,10 @@ import com.vaadin.data.validator.BeanValidator;
 import com.vaadin.server.AbstractErrorMessage;
 import com.vaadin.server.VaadinRequest;
 import com.vaadin.tests.components.AbstractTestUI;
+import com.vaadin.ui.AbstractTextField;
 import com.vaadin.ui.Button;
 import com.vaadin.ui.Label;
 import com.vaadin.ui.TextField;
-import org.apache.commons.lang.StringEscapeUtils;
 
 public class MultipleValidationErrors extends AbstractTestUI {
 
@@ -25,9 +27,15 @@ public class MultipleValidationErrors extends AbstractTestUI {
                 new PersonBeanWithValidationAnnotations());
         final FieldGroup fieldGroup = new FieldGroup(item);
 
+        // use old default that this test depends on
+        AbstractTextField.setNullRepresentationDefault("null");
+
         bindTextField(item, fieldGroup, "First Name", "firstName");
         bindTextField(item, fieldGroup, "Last Name", "lastName");
 
+        // Revert to new
+        AbstractTextField.setNullRepresentationDefault("");
+
         final Label validationErrors = new Label();
         validationErrors.setId("validationErrors");
         addComponent(validationErrors);
diff --git a/uitest/src/test/java/com/vaadin/tests/components/textfield/NullRepresentationLegacyModeTest.java b/uitest/src/test/java/com/vaadin/tests/components/textfield/NullRepresentationLegacyModeTest.java
new file mode 100644
index 0000000000..c303e8e9f1
--- /dev/null
+++ b/uitest/src/test/java/com/vaadin/tests/components/textfield/NullRepresentationLegacyModeTest.java
@@ -0,0 +1,21 @@
+package com.vaadin.tests.components.textfield;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.openqa.selenium.By;
+
+import com.vaadin.tests.tb3.MultiBrowserTest;
+
+public class NullRepresentationLegacyModeTest extends MultiBrowserTest {
+
+    @Test
+    public void testWindowRepositioning() throws Exception {
+        openTestURL();
+        String without = getDriver().findElement(
+                By.xpath("//div[@id='without']//input")).getAttribute("value");
+        String with = getDriver().findElement(
+                By.xpath("//div[@id='with']//input")).getAttribute("value");
+        Assert.assertEquals("null", with);
+        Assert.assertEquals("", without);
+    }
+}