Release 0.7.1 ready (#181)

done #171 #173 #178

README.md

@@ -19,7 +19,7 @@ This is the relevant dependency:
 <dependency>
    <groupId>org.vaadin.miki</groupId>
    <artifactId>superfields</artifactId>
-   <version>0.7.0</version>
+   <version>0.7.1</version>
 </dependency>
 ```
 

demo-v14/pom.xml

@@ -4,11 +4,11 @@
     <parent>
         <artifactId>superfields-parent</artifactId>
         <groupId>org.vaadin.miki</groupId>
-        <version>0.7.0</version>
+        <version>0.7.1</version>
     </parent>
 
     <artifactId>superfields-demo-v14</artifactId>
-    <version>0.7.0</version>
+    <version>0.7.1</version>
     <name>V14 demo app for SuperFields</name>
     <description>Showcase application for V14 and SuperFields.</description>
     <packaging>war</packaging>
@@ -23,7 +23,7 @@
         <dependency>
             <groupId>org.vaadin.miki</groupId>
             <artifactId>superfields</artifactId>
-            <version>0.7.0</version>
+            <version>0.7.1</version>
         </dependency>
         <dependency>
             <groupId>javax.servlet</groupId>

demo-v14/src/main/java/org/vaadin/miki/MainView.java

@@ -24,6 +24,7 @@
 import com.vaadin.flow.function.SerializableConsumer;
 import com.vaadin.flow.router.PageTitle;
 import com.vaadin.flow.router.Route;
+import org.slf4j.LoggerFactory;
 import org.vaadin.miki.events.text.TextSelectionNotifier;
 import org.vaadin.miki.markers.CanReceiveSelectionEventsFromClient;
 import org.vaadin.miki.markers.CanSelectText;
@@ -266,7 +267,11 @@ private void buildUnloadObserver(Component component, Consumer<Component[]> call
         final Span description = new Span("This component optionally displays a browser-native window when leaving this app. Select the checkbox above and try to close the window or tab to see it in action.");
         final Span counterText = new Span("There were this many attempts to leave this app so far: ");
         final Span counter = new Span("0");
-        ((UnloadObserver)component).addUnloadListener(event -> counter.setText(String.valueOf(Integer.parseInt(counter.getText())+1)));
+        ((UnloadObserver)component).addUnloadListener(event -> {
+            if(event.isBecauseOfQuerying())
+                counter.setText(String.valueOf(Integer.parseInt(counter.getText()) + 1));
+            LoggerFactory.getLogger(this.getClass()).info("Unload event; attempt? {}; captured in {} and UnloadObserver is inside {}", event.isBecauseOfQuerying(), this.getClass().getSimpleName(), event.getSource().getParent().orElse(this).getClass().getSimpleName());
+        });
 
         callback.accept(new Component[]{query, description, new HorizontalLayout(counterText, counter)});
     }
@@ -336,7 +341,7 @@ public MainView() {
         );
         this.components.put(ObservedField.class, new ObservedField());
         this.components.put(ComponentObserver.class, new ComponentObserver());
-        this.components.put(UnloadObserver.class, UnloadObserver.get(false));
+        this.components.put(UnloadObserver.class, UnloadObserver.get().withoutQueryingOnUnload());
         this.components.put(ItemGrid.class, new ItemGrid<Class<? extends Component>>(
                 null,
                 () -> {

pom.xml

@@ -3,7 +3,7 @@
     <modelVersion>4.0.0</modelVersion>
     <groupId>org.vaadin.miki</groupId>
     <artifactId>superfields-parent</artifactId>
-    <version>0.7.0</version>
+    <version>0.7.1</version>
     <modules>
         <module>superfields</module>
         <module>demo-v14</module>

superfields/pom.xml

@@ -8,7 +8,7 @@
     <artifactId>superfields</artifactId>
     <name>SuperFields</name>
     <description>Code for various V14+ fields and other components.</description>
-    <version>0.7.0</version>
+    <version>0.7.1</version>
 
     <properties>
         <maven.compiler.source>10</maven.compiler.source>

superfields/release-notes.md

@@ -1,3 +1,11 @@
+# 0.7.1 - Fixes to UnloadObserver
+## New features and enhancements
+* \#170 - [UnloadObserver should always send an event before unloading](https://api.github.com/repos/vaadin-miki/super-fields/issues/170)
+## Changes to API
+(nothing reported)
+## Bug fixes
+* \#178 - [UnloadObserver should belong to the UI that will be unloaded.](https://api.github.com/repos/vaadin-miki/super-fields/issues/178)
+
 # 0.7.0 - SuperTextField
 ## New features and enhancements
 * \#122 - [SuperTextField, SuperTextArea and text selection API](https://api.github.com/repos/vaadin-miki/super-fields/issues/122)

superfields/src/main/java/org/vaadin/miki/superfields/unload/UnloadEvent.java

@@ -4,18 +4,31 @@
 
 /**
  * Server-side event class associated with {@code beforeunload} event happening in the client-side.
+ * Can optionally prompt the user before leaving the page.
  * @author miki
  * @since 2020-04-29
  */
 public class UnloadEvent extends ComponentEvent<UnloadObserver> {
 
+    private final boolean becauseOfQuerying;
+
     /**
      * Creates a new event using the given source and indicator whether the
      * event originated from the client side or the server side.
      *
      * @param source     the source component
+     * @param attempted  when {@code true}, the event is fired in response to querying before unloading; {@code false} otherwise.
      */
-    public UnloadEvent(UnloadObserver source) {
+    public UnloadEvent(UnloadObserver source, boolean attempted) {
         super(source, true);
+        this.becauseOfQuerying = attempted;
+    }
+
+    /**
+     * Checks whether or not the event has been fired in response to querying the user on {@code beforeunload} browser event.
+     * @return {@code true} when event is in response to querying the user on {@code beforeunload}, {@code false} otherwise.
+     */
+    public boolean isBecauseOfQuerying() {
+        return becauseOfQuerying;
     }
 }

superfields/src/main/java/org/vaadin/miki/superfields/unload/UnloadObserver.java

@@ -2,8 +2,10 @@
 
 import com.vaadin.flow.component.AttachEvent;
 import com.vaadin.flow.component.ClientCallable;
+import com.vaadin.flow.component.ComponentUtil;
 import com.vaadin.flow.component.DetachEvent;
 import com.vaadin.flow.component.Tag;
+import com.vaadin.flow.component.UI;
 import com.vaadin.flow.component.dependency.JsModule;
 import com.vaadin.flow.component.polymertemplate.PolymerTemplate;
 import com.vaadin.flow.shared.Registration;
@@ -13,36 +15,45 @@
 /**
  * Server-side component that listens to {@code beforeunload} events.
  * Based on <a href="https://vaadin.com/forum/thread/17523194/unsaved-changes-detect-page-exit-or-reload">the code by Kaspar Scherrer and Stuart Robinson</a>.
- * Warning: this class is a Singleton; the class is final, the constructors are private and there is at most one global instance.
+ * This component will broadcast events on {@code beforeunload} event in the browser. If {@link #isQueryingOnUnload()}
+ * is {@code true}, before the event the user will be prompted about leaving the page. However, there is no way to find out what the user selected.
+ * If {@link #isQueryingOnUnload()} is {@code false}, the event on the server will be called just before the page is unloaded.
+ * Note that the component must be present in the DOM structure in the browser for the event to be received on the server.
  *
- * @author Kaspar Scherrer, Stuart Robinson; adapted to web-component by miki
+ * Warning: this class is pretty much a {@link UI}-scoped singleton; the class is final, the constructors are private and there is at most one global instance per UI.
+ *
+ * @author Kaspar Scherrer, Stuart Robinson; adapted to web-component by miki; bugfixing and enhancements by Jean-François Lamy
  * @since 2020-04-29
  */
 @JsModule("./unload-observer.js")
 @Tag("unload-observer")
 public final class UnloadObserver extends PolymerTemplate<TemplateModel> implements WithIdMixin<UnloadObserver> {
 
-    private static UnloadObserver instance = null;
-
     /**
-     * Returns the current instance. Will create one using default no-arg constructor if none is present yet.
+     * Returns or creates an instance for current UI.
+     * The result is associated with the UI, but not added to any of its components.
      * @return An instance of {@link UnloadObserver}.
+     * @throws IllegalStateException if there is no current {@link UI}.
      */
     public static UnloadObserver get() {
-        if(instance == null)
-            instance = new UnloadObserver();
-        return instance;
+        UI ui = UI.getCurrent();
+        if(ui == null)
+            throw new IllegalStateException("there is no UI available to create UnloadObserver for");
+        return get(ui);
     }
 
     /**
-     * Returns the current instance. Will create one if needed and set its {@link #setQueryingOnUnload(boolean)}.
-     * @param queryingOnUnload Whether or not query at page close.
+     * Returns or creates an instance for a given UI.
+     * The result is associated with the UI, but not added to any of its components.
+     * @param ui A {@link UI} to register the instance of {@link UnloadObserver} in. Must not be {@code null}.
      * @return An instance of {@link UnloadObserver}.
      */
-    public static UnloadObserver get(boolean queryingOnUnload) {
-        if(instance == null)
-            instance = new UnloadObserver(queryingOnUnload);
-        else instance.setQueryingOnUnload(queryingOnUnload);
+    public static UnloadObserver get(UI ui) {
+        UnloadObserver instance = ComponentUtil.getData(ui, UnloadObserver.class);
+        if(instance == null) {
+            instance = new UnloadObserver();
+            ComponentUtil.setData(ui, UnloadObserver.class, instance);
+        }
         return instance;
     }
 
@@ -131,9 +142,14 @@ protected void onDetach(DetachEvent detachEvent) {
         super.onDetach(detachEvent);
     }
 
+    @ClientCallable
+    private void unloadHappened() {
+        this.fireUnloadEvent(new UnloadEvent(this, false));
+    }
+
     @ClientCallable
     private void unloadAttempted() {
-        this.fireUnloadEvent(new UnloadEvent(this));
+        this.fireUnloadEvent(new UnloadEvent(this, true));
     }
 
     /**
@@ -152,5 +168,4 @@ protected void fireUnloadEvent(UnloadEvent event) {
     public Registration addUnloadListener(UnloadListener listener) {
         return this.getEventBus().addListener(UnloadEvent.class, listener);
     }
-
 }

superfields/src/main/resources/META-INF/resources/frontend/unload-observer.js

@@ -23,29 +23,31 @@ export class UnloadObserver extends PolymerElement {
         const src = this;
         if (window.Vaadin.unloadObserver === undefined) {
             window.Vaadin.unloadObserver = {
-                handler: undefined
+                attemptHandler: undefined
             }
         }
-        if (window.Vaadin.unloadObserver.handler !== undefined) {
-            window.removeEventListener('beforeunload', window.Vaadin.unloadObserver.handler);
+        if (window.Vaadin.unloadObserver.attemptHandler !== undefined) {
+            window.removeEventListener('beforeunload', window.Vaadin.unloadObserver.attemptHandler);
         }
-        window.Vaadin.unloadObserver.handler = event => src.unloadHappened(src, event);
-        window.addEventListener('beforeunload', window.Vaadin.unloadObserver.handler);
+        window.Vaadin.unloadObserver.attemptHandler = event => src.unloadAttempted(src, event);
+        window.addEventListener('beforeunload', window.Vaadin.unloadObserver.attemptHandler);
     }
 
     /**
      * Invoked in response to beforeunload browser event.
      * @param source An unload observer.
      * @param event Event that happened.
      */
-    unloadHappened(source, event) {
+    unloadAttempted(source, event) {
         if (window.Vaadin.unloadObserver.query) {
+            console.log("UO: responding to unload attempt...");
             event.preventDefault();
             event.returnValue = '';
             if (source.$server) {
                 source.$server.unloadAttempted();
             }
         }
+        else source.$server.unloadHappened();
     }
 
     /**