feat: Add target enums for Anchor (#8346) (#8397)

Co-authored-by: Denis Anisimov <[email protected]>

flow-html-components/src/main/java/com/vaadin/flow/component/html/Anchor.java

@@ -15,6 +15,7 @@
  */
 package com.vaadin.flow.component.html;
 
+import java.util.Objects;
 import java.util.Optional;
 
 import com.vaadin.flow.component.Component;
@@ -39,7 +40,8 @@ public class Anchor extends HtmlContainer implements Focusable<Anchor> {
             .attributeWithDefault("href", "", false);
 
     private static final PropertyDescriptor<String, Optional<String>> targetDescriptor = PropertyDescriptors
-            .optionalAttributeWithDefault("target", "");
+            .optionalAttributeWithDefault("target",
+                    AnchorTarget.DEFAULT.getValue());
 
     private static final String ROUTER_IGNORE_ATTRIBUTE = "router-ignore";
 
@@ -66,6 +68,26 @@ public Anchor(String href, String text) {
         setText(text);
     }
 
+    /**
+     * Creates an anchor component with the given target, text content and href.
+     *
+     * @see #setHref(String)
+     * @see #setText(String)
+     * @see #setTarget(AnchorTargetValue)
+     *
+     * @param href
+     *            the href to set
+     * @param text
+     *            the text content to set
+     * @param target
+     *            the target window, tab or frame
+     */
+    public Anchor(String href, String text, AnchorTarget target) {
+        setHref(href);
+        setText(text);
+        setTarget(target);
+    }
+
     /**
      * Creates an anchor component with the given text content and stream
      * resource.
@@ -183,4 +205,47 @@ public Optional<String> getTarget() {
         return get(targetDescriptor);
     }
 
+    /**
+     * Sets the target window, tab or frame for this anchor. The target may be
+     * the one of these special values:
+     * <ul>
+     * <li><code>AnchorTarget.DEFAULT</code>: Removes the target value. This has
+     * the same effect as setting the target to <code>AnchorTarget.SELF</code>.
+     * <li><code>AnchorTarget.SELF</code>: Opens the link in the current
+     * context.
+     * <li><code>AnchorTarget.BLANK</code>: Opens the link in a new unnamed
+     * context.
+     * <li><code>AnchorTarget.PARENT</code>: Opens the link in the parent
+     * context, or the current context if there is no parent context.
+     * <li><code>AnchorTarget.TOP</code>: Opens the link in the top most
+     * grandparent context, or the current context if there is no parent
+     * context.
+     * </ul>
+     *
+     * @param target
+     *            the target value, not null
+     */
+    public void setTarget(AnchorTargetValue target) {
+        Objects.requireNonNull(target, "target cannot be null.");
+        setTarget(target.getValue());
+    }
+
+    /**
+     * Gets the target window, tab or frame value for this anchor.
+     *
+     * @see #setTarget(AnchorTargetValue)
+     * @see #getTarget()
+     *
+     * @return the target window value , or {@link AnchorTarget#DEFAULT} if no
+     *         target has been set
+     */
+    public AnchorTargetValue getTargetValue() {
+        Optional<String> target = getTarget();
+
+        if (target.isPresent()) {
+            return AnchorTargetValue.forString(target.get());
+        }
+        return AnchorTarget.DEFAULT;
+    }
+
 }

flow-html-components/src/main/java/com/vaadin/flow/component/html/AnchorTarget.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2000-2020 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.flow.component.html;
+
+/**
+ * Enum representing <code>target</code> attribute values for an
+ * <code>&lt;a&gt;</code> element.
+ *
+ * @author Vaadin Ltd
+ * @since
+ */
+public enum AnchorTarget implements AnchorTargetValue {
+    /**
+     * Remove the target value. This has the same effect as <code>SELF</code>.
+     */
+    DEFAULT(""),
+    /**
+     * Open a link in the current context.
+     */
+    SELF("_self"),
+    /**
+     * Open a link in a new unnamed context.
+     */
+    BLANK("_blank"),
+    /**
+     * Open a link in the parent context, or the current context if there is no
+     * parent context.
+     */
+    PARENT("_parent"),
+    /**
+     * Open a link in the top most grandparent context, or the current context
+     * if there is no parent context.
+     */
+    TOP("_top");
+
+    private final String value;
+
+    /**
+     * @param value
+     *            the text value to use by an {@code <a>} (anchor) tag.
+     */
+    AnchorTarget(String value) {
+        this.value = value;
+    }
+
+    /**
+     * @return value the text value to use by an {@code <a>} (anchor) tag.
+     */
+    @Override
+    public String getValue() {
+        return value;
+    }
+
+}

flow-html-components/src/main/java/com/vaadin/flow/component/html/AnchorTargetValue.java

@@ -0,0 +1,84 @@
+/*
+ * Copyright 2000-2021 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.flow.component.html;
+
+import java.io.Serializable;
+import java.util.Objects;
+import java.util.Optional;
+import java.util.stream.Stream;
+
+/**
+ * Represents <code>target</code> attribute values for an <code>&lt;a&gt;</code>
+ * element.
+ * 
+ * @author Vaadin Ltd
+ * @since
+ * 
+ * @see AnchorTarget
+ *
+ */
+@FunctionalInterface
+public interface AnchorTargetValue extends Serializable {
+
+    /**
+     * Gets the string value representation.
+     * 
+     * @return string value representation
+     */
+    String getValue();
+
+    /**
+     * Gets an object instance wrapping the {@code value} string representation.
+     * 
+     * @param value
+     *            the string value representation, not {@code null}
+     * @return an object wrapping the string value
+     */
+    public static AnchorTargetValue forString(String value) {
+        Optional<AnchorTarget> target = Stream.of(AnchorTarget.values()).filter(
+                type -> type.getValue().equals(Objects.requireNonNull(value)))
+                .findFirst();
+        if (target.isPresent()) {
+            return target.get();
+        }
+        return new AnchorTargetValue() {
+
+            @Override
+            public String getValue() {
+                return value;
+            }
+
+            @Override
+            public boolean equals(Object obj) {
+                if (obj == null) {
+                    return false;
+                }
+                if (obj == this) {
+                    return true;
+                }
+                if (!obj.getClass().equals(getClass())) {
+                    return false;
+                }
+                return value.equals(((AnchorTargetValue) obj).getValue());
+            }
+
+            @Override
+            public int hashCode() {
+                return value.hashCode();
+            }
+        };
+    }
+}

flow-html-components/src/test/java/com/vaadin/flow/component/html/AnchorTargetValueTest.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2000-2021 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.flow.component.html;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class AnchorTargetValueTest {
+
+    @Test
+    public void fromString_notEnum_objectHasValueAndEquals() {
+        AnchorTargetValue value = AnchorTargetValue.forString("foo");
+        Assert.assertEquals("foo", value.getValue());
+
+        AnchorTargetValue value1 = AnchorTargetValue.forString("foo");
+        Assert.assertEquals(value, value1);
+        Assert.assertEquals(value.hashCode(), value1.hashCode());
+    }
+
+    @Test
+    public void fromString_enumValue_resultIsEnum() {
+        AnchorTargetValue value = AnchorTargetValue
+                .forString(AnchorTarget.TOP.getValue());
+        Assert.assertEquals(AnchorTarget.TOP, value);
+    }
+}

flow-html-components/src/test/java/com/vaadin/flow/component/html/AnchorTest.java

@@ -15,10 +15,13 @@
  */
 package com.vaadin.flow.component.html;
 
-import com.vaadin.flow.component.Text;
+import java.util.Optional;
+
 import org.junit.Assert;
 import org.junit.Test;
 
+import com.vaadin.flow.component.Text;
+
 public class AnchorTest extends ComponentTest {
 
     @Test
@@ -35,7 +38,27 @@ public void removeHref() {
     public void createWithComponent() {
         Anchor anchor = new Anchor("#", new Text("Home"));
         Assert.assertEquals(anchor.getElement().getAttribute("href"), "#");
+        Assert.assertEquals(anchor.getHref(), "#");
         Assert.assertEquals(anchor.getElement().getText(), "Home");
+        Assert.assertEquals(anchor.getText(), "Home");
+    }
+
+    @Test
+    public void createWithTarget() {
+        Anchor anchor = new Anchor("#", "Home");
+        Assert.assertEquals(anchor.getTargetValue(), AnchorTarget.DEFAULT);
+        Assert.assertEquals(anchor.getTarget(), Optional.empty());
+
+        anchor.setTarget(AnchorTarget.BLANK);
+
+        Assert.assertEquals(anchor.getTargetValue(), AnchorTarget.BLANK);
+        Assert.assertEquals(anchor.getTarget(),
+                Optional.of(AnchorTarget.BLANK.getValue()));
+
+        Assert.assertEquals(anchor.getTargetValue(),
+                new Anchor("#", "Home", AnchorTarget.BLANK).getTargetValue());
+        Assert.assertEquals(anchor.getTarget(),
+                new Anchor("#", "Home", AnchorTarget.BLANK).getTarget());
     }
 
     @Test
@@ -60,6 +83,44 @@ public void shouldNotBreakBehaviorIfSetHrefWhenHavingRouterIgnoreAttributeBefore
                 anchor.getElement().getAttribute("router-ignore"));
     }
 
+    @Test
+    public void setTargetValue_useEnum_targetIsSet() {
+        Anchor anchor = new Anchor();
+        anchor.setTarget(AnchorTarget.PARENT);
+
+        Assert.assertEquals(Optional.of(AnchorTarget.PARENT.getValue()),
+                anchor.getTarget());
+        Assert.assertEquals(AnchorTarget.PARENT, anchor.getTargetValue());
+    }
+
+    @Test
+    public void setTargetValue_useObject_targetIsSet() {
+        Anchor anchor = new Anchor();
+        anchor.setTarget(AnchorTargetValue.forString("foo"));
+
+        Assert.assertEquals(Optional.of("foo"), anchor.getTarget());
+        Assert.assertEquals("foo", anchor.getTargetValue().getValue());
+    }
+
+    @Test
+    public void getTargetValue_useEnumStringValue_targetIsReturned() {
+        Anchor anchor = new Anchor();
+        anchor.setTarget(AnchorTarget.SELF.getValue());
+
+        Assert.assertEquals(Optional.of(AnchorTarget.SELF.getValue()),
+                anchor.getTarget());
+        Assert.assertEquals(AnchorTarget.SELF, anchor.getTargetValue());
+    }
+
+    @Test
+    public void getTargetValue_useSomeStringValue_targetIsReturned() {
+        Anchor anchor = new Anchor();
+        anchor.setTarget("foo");
+
+        Assert.assertEquals(Optional.of("foo"), anchor.getTarget());
+        Assert.assertEquals("foo", anchor.getTargetValue().getValue());
+    }
+
     // Other test methods in super class
 
     @Override