Test that cross field validation works as expected (#33).

Test for cross field validation from Book of Vaadin.

Change-Id: Ida338bd79456332b3a359217ea7b9900a1408153

3 files changed, 88 insertions, 8 deletions

diff --git a/documentation/datamodel/datamodel-forms.asciidoc b/documentation/datamodel/datamodel-forms.asciidoc
index 3bea6f857c..8acbffdd7a 100644
--- a/documentation/datamodel/datamodel-forms.asciidoc
+++ b/documentation/datamodel/datamodel-forms.asciidoc
@@ -205,15 +205,13 @@ PopupDateField departing = new PopupDateField("Departing");
 PopupDateField returning = new PopupDateField("Returning");
 
 // Store return date binding so we can revalidate it later
-FieldBinding<Trip, LocalDate> returnBinding = binder
-  .forField(returning)
-  .withValidator(
-    returnDate -> !returnDate.isBefore(departing.getValue()),
-    "Cannot return before departing")
-  .bind(Trip::getReturnDate, Trip::setReturnDate);
+Binding<Trip, Date, Date> returnBinding = binder.forField(returning)
+  .withValidator(returnDate -> !returnDate.before(departing.getValue()),
+  "Cannot return before departing");
+returnBinding.bind(Trip::getReturnDate, Trip::setReturnDate);
 
 // Revalidate return date when departure date changes
-departing.onChange(newValue -> returnBinding.validate());
+departing.addValueChangeListener(event -> returnBinding.validate());
 ----
 
 == Converting User Input
diff --git a/server/src/main/java/com/vaadin/data/Binder.java b/server/src/main/java/com/vaadin/data/Binder.java
index 8c637118d6..5ce80d2c0b 100644
--- a/server/src/main/java/com/vaadin/data/Binder.java
+++ b/server/src/main/java/com/vaadin/data/Binder.java
@@ -262,6 +262,17 @@ public class Binder<BEAN> implements Serializable {
          */
         public HasValue<FIELDVALUE> getField();
 
+        /**
+         * Validates the field value and returns a {@code Result} instance
+         * representing the outcome of the validation.
+         * 
+         * @see Binder#validate()
+         * @see Validator#apply(Object)
+         *
+         * @return the validation result.
+         */
+        public Result<TARGET> validate();
+
     }
 
     /**
@@ -372,7 +383,8 @@ public class Binder<BEAN> implements Serializable {
                     .addValueChangeListener(e -> storeFieldValue(bean));
         }
 
-        private Result<TARGET> validate() {
+        @Override
+        public Result<TARGET> validate() {
             FIELDVALUE fieldValue = field.getValue();
             Result<TARGET> dataValue = converterValidatorChain.convertToModel(
                     fieldValue, ((AbstractComponent) field).getLocale());
diff --git a/server/src/test/java/com/vaadin/data/BinderBookOfVaadinTest.java b/server/src/test/java/com/vaadin/data/BinderBookOfVaadinTest.java
index 74cec124a6..6fcfe61ce3 100644
--- a/server/src/test/java/com/vaadin/data/BinderBookOfVaadinTest.java
+++ b/server/src/test/java/com/vaadin/data/BinderBookOfVaadinTest.java
@@ -15,6 +15,8 @@
  */
 package com.vaadin.data;
 
+import java.util.Calendar;
+import java.util.Date;
 import java.util.List;
 
 import org.junit.Assert;
@@ -26,6 +28,7 @@ import com.vaadin.data.util.converter.StringToIntegerConverter;
 import com.vaadin.data.validator.EmailValidator;
 import com.vaadin.server.AbstractErrorMessage;
 import com.vaadin.ui.AbstractField;
+import com.vaadin.ui.PopupDateField;
 import com.vaadin.ui.Slider;
 
 /**
@@ -95,6 +98,18 @@ public class BinderBookOfVaadinTest {
 
     }
 
+    public static class Trip {
+        private Date returnDate;
+
+        public Date getReturnDate() {
+            return returnDate;
+        }
+
+        public void setReturnDate(Date returnDate) {
+            this.returnDate = returnDate;
+        }
+    }
+
     private Binder<BookPerson> binder;
 
     private TextField field;
@@ -238,4 +253,59 @@ public class BinderBookOfVaadinTest {
                 yearOfBirthField.getComponentError().getFormattedHtmlMessage());
     }
 
+    @Test
+    public void crossFieldValidation() {
+        Binder<Trip> binder = new Binder<>();
+        PopupDateField departing = new PopupDateField("Departing");
+        PopupDateField returning = new PopupDateField("Returning");
+
+        Binding<Trip, Date, Date> returnBinding = binder.forField(returning)
+                .withValidator(
+                        returnDate -> !returnDate.before(departing.getValue()),
+                        "Cannot return before departing");
+
+        returnBinding.bind(Trip::getReturnDate, Trip::setReturnDate);
+        departing.addValueChangeListener(event -> returnBinding.validate());
+
+        Calendar calendar = Calendar.getInstance();
+        Date past = calendar.getTime();
+        calendar.add(1, Calendar.DAY_OF_YEAR);
+        Date before = calendar.getTime();
+        calendar.add(1, Calendar.DAY_OF_YEAR);
+        Date after = calendar.getTime();
+
+        departing.setValue(before);
+        returning.setValue(after);
+
+        List<ValidationError<?>> errors = binder.validate();
+        Assert.assertTrue(errors.isEmpty());
+        Assert.assertNull(departing.getComponentError());
+        Assert.assertNull(returning.getComponentError());
+
+        // update returning => validation is done against this field
+        returning.setValue(past);
+        errors = binder.validate();
+
+        Assert.assertFalse(errors.isEmpty());
+        Assert.assertNotNull(returning.getComponentError());
+        Assert.assertNull(departing.getComponentError());
+
+        // set correct value back
+        returning.setValue(before);
+        errors = binder.validate();
+
+        Assert.assertTrue(errors.isEmpty());
+        Assert.assertNull(departing.getComponentError());
+        Assert.assertNull(returning.getComponentError());
+
+        // update departing => validation is done because of listener added
+        departing.setValue(after);
+        errors = binder.validate();
+
+        Assert.assertFalse(errors.isEmpty());
+        Assert.assertNotNull(returning.getComponentError());
+        Assert.assertNull(departing.getComponentError());
+
+    }
+
 }