Make view parameter map available in ViewChangeEvent (#9529)

3 files changed, 105 insertions, 2 deletions

diff --git a/server/src/main/java/com/vaadin/navigator/Navigator.java b/server/src/main/java/com/vaadin/navigator/Navigator.java
index 8b9e39b354..da5dfa0f87 100644
--- a/server/src/main/java/com/vaadin/navigator/Navigator.java
+++ b/server/src/main/java/com/vaadin/navigator/Navigator.java
@@ -755,6 +755,7 @@ public class Navigator implements Serializable {
      *
      * @return The parameters from the navigation state as a map
      * @see #getStateParameterMap(String)
+     * @since 8.1
      */
     public Map<String, String> getStateParameterMap() {
         return getStateParameterMap(DEFAULT_STATE_PARAMETER_SEPARATOR);
@@ -771,21 +772,22 @@ public class Navigator implements Serializable {
      *            from each other
      * @return The parameters from the navigation state as a map
      * @see #getStateParameterMap()
+     * @since 8.1
      */
     public Map<String, String> getStateParameterMap(String separator) {
         return parseStateParameterMap(Objects.requireNonNull(separator));
     }
 
     /**
-     * Parses the state parameter map using given separator String.
+     * Parses the state parameter to a map using the given separator string.
      *
      * @param separator
      *            the string (typically one character) used to separate values
      *            from each other
      * @return The navigation state as Map<String, String>.
+     * @since 8.1
      */
     protected Map<String, String> parseStateParameterMap(String separator) {
-        Map<String, String> parameterMap = new HashMap<>();
         if (getState() == null || getState().isEmpty()) {
             return Collections.emptyMap();
         }
@@ -800,9 +802,28 @@ public class Navigator implements Serializable {
             parameterString = state.substring(viewSeparatorLocation + 1,
                     state.length());
         }
+        return parseParameterStringToMap(parameterString, separator);
+    }
+
+    /**
+     * Parses the given parameter string to a map using the given separator
+     * string.
+     *
+     * @param parameterString
+     *            the parameter string to parse
+     * @param separator
+     *            the string (typically one character) used to separate values
+     *            from each other
+     * @return The navigation state as Map<String, String>.
+     * @since 8.1
+     */
+    protected Map<String, String> parseParameterStringToMap(
+            String parameterString, String separator) {
         if (parameterString.isEmpty()) {
             return Collections.emptyMap();
         }
+
+        Map<String, String> parameterMap = new HashMap<>();
         String[] parameters = parameterString.split(separator);
         for (int i = 0; i < parameters.length; i++) {
             String[] keyAndValue = parameters[i]
diff --git a/server/src/main/java/com/vaadin/navigator/ViewChangeListener.java b/server/src/main/java/com/vaadin/navigator/ViewChangeListener.java
index 9238f1bae9..c5a1c68c65 100644
--- a/server/src/main/java/com/vaadin/navigator/ViewChangeListener.java
+++ b/server/src/main/java/com/vaadin/navigator/ViewChangeListener.java
@@ -18,6 +18,7 @@ package com.vaadin.navigator;
 
 import java.io.Serializable;
 import java.util.EventObject;
+import java.util.Map;
 
 /**
  * Interface for listening to View changes before and after they occur.
@@ -104,6 +105,33 @@ public interface ViewChangeListener extends Serializable {
         public String getParameters() {
             return parameters;
         }
+
+        /**
+         * Returns the parameters for the view being activated parsed to a map,
+         * using {@literal &} as the parameter separator character.
+         *
+         * @return navigation parameters (potentially bookmarkable) for the new
+         *         view
+         * @since 8.1
+         */
+        public Map<String, String> getParameterMap() {
+            return getParameterMap("&");
+        }
+
+        /**
+         * Returns the parameters for the view being activated parsed to a map,
+         * using the given string as the parameter separator character.
+         *
+         * @param separator
+         *            the parameter separator string to use
+         * @return navigation parameters (potentially bookmarkable) for the new
+         *         view
+         * @since 8.1
+         */
+        public Map<String, String> getParameterMap(String separator) {
+            return getNavigator().parseParameterStringToMap(getParameters(),
+                    separator);
+        }
     }
 
     /**
diff --git a/server/src/test/java/com/vaadin/tests/server/navigator/NavigatorTest.java b/server/src/test/java/com/vaadin/tests/server/navigator/NavigatorTest.java
index 022b388840..fbc55d57cc 100644
--- a/server/src/test/java/com/vaadin/tests/server/navigator/NavigatorTest.java
+++ b/server/src/test/java/com/vaadin/tests/server/navigator/NavigatorTest.java
@@ -25,6 +25,7 @@ import static org.junit.Assert.fail;
 import java.util.LinkedList;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.concurrent.atomic.AtomicReference;
 
 import org.easymock.EasyMock;
 import org.easymock.IArgumentMatcher;
@@ -1060,4 +1061,57 @@ public class NavigatorTest {
         manager.setState(state);
         return navigator;
     }
+
+    @Test
+    public void parameterMapFromViewChangeEvent() {
+        // create navigator to test
+        Navigator navigator = createNavigatorWithState("foo");
+        View view1 = EasyMock.createMock(View.class);
+        View view2 = EasyMock.createMock(View.class);
+        ViewProvider provider = new ViewProvider() {
+
+            @Override
+            public String getViewName(String viewAndParameters) {
+                if (viewAndParameters.contains("/")) {
+                    return viewAndParameters.substring(0,
+                            viewAndParameters.indexOf('/'));
+                } else {
+                    return viewAndParameters;
+                }
+            }
+
+            @Override
+            public View getView(String viewName) {
+                if (viewName.equals("view1")) {
+                    return view1;
+                } else if (viewName.equals("view2")) {
+                    return view2;
+                } else {
+                    return null;
+                }
+            }
+        };
+        navigator.addProvider(provider);
+
+        AtomicReference<Map<String, String>> mapRef = new AtomicReference<>();
+        AtomicReference<Map<String, String>> mapRefB = new AtomicReference<>();
+        navigator.addViewChangeListener(new ViewChangeListener() {
+            @Override
+            public boolean beforeViewChange(ViewChangeEvent event) {
+                mapRef.set(event.getParameterMap());
+                mapRefB.set(event.getParameterMap("b"));
+                return true;
+            }
+        });
+
+        navigator.navigateTo("view1");
+
+        Assert.assertTrue(mapRef.get().isEmpty());
+        Assert.assertTrue(mapRefB.get().isEmpty());
+        navigator.navigateTo("view1/a&b=c&d");
+
+        assertMap(mapRef.get(), entry("a", ""), entry("b", "c"),
+                entry("d", ""));
+        assertMap(mapRefB.get(), entry("a&", ""), entry("", "c&d"));
+    }
 }