Add internal state validators for HasValue (#9532)

This also fixes/improves AbstractDateField validation.

5 files changed, 136 insertions, 2 deletions

diff --git a/server/src/main/java/com/vaadin/data/Binder.java b/server/src/main/java/com/vaadin/data/Binder.java
index 26720a3274..ae467be123 100644
--- a/server/src/main/java/com/vaadin/data/Binder.java
+++ b/server/src/main/java/com/vaadin/data/Binder.java
@@ -1190,7 +1190,8 @@ public class Binder<BEAN> implements Serializable {
         getStatusLabel().ifPresent(label -> label.setValue(""));
 
         return createBinding(field, createNullRepresentationAdapter(field),
-                this::handleValidationStatus);
+                this::handleValidationStatus)
+                        .withValidator(field.getDefaultValidator());
     }
 
     /**
diff --git a/server/src/main/java/com/vaadin/data/HasValue.java b/server/src/main/java/com/vaadin/data/HasValue.java
index 935f365e10..aad436a089 100644
--- a/server/src/main/java/com/vaadin/data/HasValue.java
+++ b/server/src/main/java/com/vaadin/data/HasValue.java
@@ -292,4 +292,19 @@ public interface HasValue<V> extends Serializable {
     public default void clear() {
         setValue(getEmptyValue());
     }
+
+    /**
+     * Returns a validator that checks the internal state of the HasValue. This
+     * should be overridden for components with internal value conversion or
+     * validation, eg. when the user is providing a string that has to be parsed
+     * into a date. An invalid input from user will be exposed to
+     * a {@link Binder} and can be seen as a validation failure.
+     * 
+     * @since 8.1
+     * @return internal state validator
+     * @see Binder#validate()
+     */
+    public default Validator<V> getDefaultValidator() {
+        return Validator.alwaysPass();
+    }
 }
diff --git a/server/src/main/java/com/vaadin/ui/AbstractDateField.java b/server/src/main/java/com/vaadin/ui/AbstractDateField.java
index 0e738de253..0b1f60c0e4 100644
--- a/server/src/main/java/com/vaadin/ui/AbstractDateField.java
+++ b/server/src/main/java/com/vaadin/ui/AbstractDateField.java
@@ -38,6 +38,7 @@ import org.jsoup.nodes.Element;
 import com.googlecode.gentyref.GenericTypeReflector;
 import com.vaadin.data.Result;
 import com.vaadin.data.ValidationResult;
+import com.vaadin.data.Validator;
 import com.vaadin.data.ValueContext;
 import com.vaadin.data.validator.RangeValidator;
 import com.vaadin.event.FieldEvents.BlurEvent;
@@ -302,7 +303,10 @@ public abstract class AbstractDateField<T extends Temporal & TemporalAdjuster &
 
                     markAsDirty();
                 } else {
-                    parsedDate.ifOk(value -> setValue(value, true));
+                    parsedDate.ifOk(value -> {
+                        currentParseErrorMessage = null;
+                        setValue(value, true);
+                    });
 
                     /*
                      * Ensure the value is sent to the client if the value is
@@ -315,6 +319,7 @@ public abstract class AbstractDateField<T extends Temporal & TemporalAdjuster &
 
             } else if (newDate != oldDate
                     && (newDate == null || !newDate.equals(oldDate))) {
+                currentParseErrorMessage = null;
                 setValue(newDate, true); // Don't require a repaint, client
                 // updates itself
             } else if (!uiHasValidDateString) {
@@ -767,4 +772,17 @@ public abstract class AbstractDateField<T extends Temporal & TemporalAdjuster &
                 .collect(Collectors.toList());
     }
 
+    @Override
+    public Validator<T> getDefaultValidator() {
+        return new Validator<T>() {
+            @Override
+            public ValidationResult apply(T value, ValueContext context) {
+                if (currentParseErrorMessage != null) {
+                    return ValidationResult.error(currentParseErrorMessage);
+                }
+                // Pass to range validator.
+                return getRangeValidator().apply(value, context);
+            }
+        };
+    }
 }
diff --git a/uitest/src/main/java/com/vaadin/tests/components/datefield/DateFieldFaultyInputNotValid.java b/uitest/src/main/java/com/vaadin/tests/components/datefield/DateFieldFaultyInputNotValid.java
new file mode 100644
index 0000000000..cbc87e5386
--- /dev/null
+++ b/uitest/src/main/java/com/vaadin/tests/components/datefield/DateFieldFaultyInputNotValid.java
@@ -0,0 +1,28 @@
+package com.vaadin.tests.components.datefield;
+
+import java.time.LocalDate;
+
+import com.vaadin.annotations.Widgetset;
+import com.vaadin.data.Binder;
+import com.vaadin.server.VaadinRequest;
+import com.vaadin.tests.components.AbstractTestUI;
+import com.vaadin.ui.Button;
+import com.vaadin.ui.DateField;
+import com.vaadin.ui.Notification;
+
+@Widgetset("com.vaadin.DefaultWidgetSet")
+public class DateFieldFaultyInputNotValid extends AbstractTestUI {
+
+    @Override
+    protected void setup(VaadinRequest request) {
+        DateField df = new DateField();
+        Binder<Void> binder = new Binder<>();
+        binder.forField(df).bind(v -> LocalDate.now(), (v, t) -> {
+            /* NO-OP */ });
+        df.setRangeStart(LocalDate.now().minusDays(2));
+        addComponent(df);
+        addComponent(new Button("Validate", e -> Notification
+                .show(binder.validate().isOk() ? "OK" : "Fail")));
+    }
+
+}
diff --git a/uitest/src/test/java/com/vaadin/tests/components/datefield/DateFieldFaultyInputNotValidTest.java b/uitest/src/test/java/com/vaadin/tests/components/datefield/DateFieldFaultyInputNotValidTest.java
new file mode 100644
index 0000000000..1fd335b671
--- /dev/null
+++ b/uitest/src/test/java/com/vaadin/tests/components/datefield/DateFieldFaultyInputNotValidTest.java
@@ -0,0 +1,72 @@
+package com.vaadin.tests.components.datefield;
+
+import java.time.LocalDate;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.openqa.selenium.By;
+import org.openqa.selenium.interactions.Actions;
+
+import com.vaadin.testbench.elements.ButtonElement;
+import com.vaadin.testbench.elements.DateFieldElement;
+import com.vaadin.testbench.elements.NotificationElement;
+import com.vaadin.tests.tb3.SingleBrowserTest;
+
+public class DateFieldFaultyInputNotValidTest extends SingleBrowserTest {
+
+    @Test
+    public void testEmptyDateFieldOK() {
+        openTestURL();
+        $(ButtonElement.class).first().click();
+        Assert.assertEquals("Empty DateField should be ok", "OK",
+                $(NotificationElement.class).first().getText());
+    }
+
+    @Test
+    public void testFaultyUserInput() {
+        openTestURL();
+        DateFieldElement dateField = $(DateFieldElement.class).first();
+        dateField.setDate(LocalDate.now());
+
+        $(ButtonElement.class).first().click();
+        Assert.assertEquals("Current date should be ok", "OK",
+                $(NotificationElement.class).first().getText());
+        $(NotificationElement.class).first().close();
+
+        dateField.findElement(By.tagName("input")).click();
+        new Actions(getDriver()).sendKeys("asd").perform();
+
+        $(ButtonElement.class).first().click();
+        Assert.assertEquals("Added 'asd' should make date not parse correctly.",
+                "Fail", $(NotificationElement.class).first().getText());
+    }
+
+    @Test
+    public void testDateOutOfRange() {
+        openTestURL();
+        DateFieldElement dateField = $(DateFieldElement.class).first();
+        dateField.setDate(LocalDate.now());
+
+        $(ButtonElement.class).first().click();
+        Assert.assertEquals("Current date should be ok", "OK",
+                $(NotificationElement.class).first().getText());
+        $(NotificationElement.class).first().close();
+
+        dateField.setDate(LocalDate.now().minusDays(7));
+
+        $(ButtonElement.class).first().click();
+        Assert.assertEquals("Last week should not be ok", "Fail",
+                $(NotificationElement.class).first().getText());
+    }
+
+    @Test
+    public void testParseErrorClearedOnValidInput() {
+        testFaultyUserInput();
+        $(NotificationElement.class).first().close();
+
+        $(DateFieldElement.class).first().setDate(LocalDate.now());
+        $(ButtonElement.class).first().click();
+        Assert.assertEquals("Current date should be ok", "OK",
+                $(NotificationElement.class).first().getText());
+    }
+}