Add support for pluggable filters for rewriting dependencies (#9182)

* Add support for pluggable filters for rewriting dependencies

Fixes #9151

server/src/main/java/com/vaadin/server/BootstrapHandler.java

@@ -44,6 +44,7 @@ import org.jsoup.parser.Tag;
 
 import com.vaadin.annotations.Viewport;
 import com.vaadin.annotations.ViewportGeneratorClass;
+import com.vaadin.server.DependencyFilter.FilterContext;
 import com.vaadin.server.communication.AtmospherePushConnection;
 import com.vaadin.shared.ApplicationConstants;
 import com.vaadin.shared.VaadinUriResolver;
@@ -572,9 +573,10 @@ public abstract class BootstrapHandler extends SynchronizedRequestHandler {
                     .attr("href", themeUri + "/favicon.ico");
         }
 
-        Collection<? extends Dependency> deps = Dependency.findDependencies(
-                Collections.singletonList(uiClass),
-                context.getSession().getCommunicationManager());
+        Collection<? extends Dependency> deps = Dependency
+                .findAndFilterDependencies(Collections.singletonList(uiClass),
+                        context.getSession().getCommunicationManager(),
+                        new FilterContext(context.getSession()));
         for (Dependency dependency : deps) {
             Type type = dependency.getType();
             String url = context.getUriResolver()

server/src/main/java/com/vaadin/server/DependencyFilter.java

@@ -0,0 +1,88 @@
+/*
+ * Copyright 2000-2016 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.server;
+
+import java.io.Serializable;
+import java.util.List;
+
+import com.vaadin.annotations.HtmlImport;
+import com.vaadin.annotations.JavaScript;
+import com.vaadin.annotations.StyleSheet;
+import com.vaadin.ui.Dependency;
+
+/**
+ * Filter for dependencies loaded using {@link StyleSheet @StyleSheet},
+ * {@link JavaScript @JavaScript} and {@link HtmlImport @HtmlImport}.
+ *
+ * @since
+ */
+public interface DependencyFilter extends Serializable {
+
+    /**
+     * Filters the list of dependencies and returns a (possibly) updated
+     * version.
+     * <p>
+     * Called whenever dependencies are about to be sent to the client side for
+     * loading.
+     *
+     * @param dependencies
+     *            the collected dependencies, possibly already modified by other
+     *            filters
+     * @param filterContext
+     *            context information, e.g about the target UI
+     * @return a list of dependencies to load
+     */
+    public List<Dependency> filter(List<Dependency> dependencies,
+            FilterContext filterContext);
+
+    /**
+     * Provides context information for the dependency filter operation.
+     *
+     * @since
+     */
+    public static class FilterContext implements Serializable {
+
+        private VaadinSession session;
+
+        /**
+         * Creates a new context for the given session.
+         *
+         * @param session
+         *            the session which is loading dependencies
+         */
+        public FilterContext(VaadinSession session) {
+            this.session = session;
+        }
+
+        /**
+         * Gets the related Vaadin session.
+         *
+         * @return the Vaadin session
+         */
+        public VaadinSession getSession() {
+            return session;
+        }
+
+        /**
+         * Gets the related Vaadin service.
+         *
+         * @return the Vaadin service
+         */
+        public VaadinService getService() {
+            return session.getService();
+        }
+    }
+}

server/src/main/java/com/vaadin/server/VaadinService.java

@@ -135,6 +135,7 @@ public abstract class VaadinService implements Serializable {
     private ClassLoader classLoader;
 
     private Iterable<RequestHandler> requestHandlers;
+    private Iterable<DependencyFilter> dependencyFilters;
 
     private boolean atmosphereAvailable = checkAtmosphereSupport();
 
@@ -206,6 +207,8 @@ public abstract class VaadinService implements Serializable {
 
         requestHandlers = Collections.unmodifiableCollection(handlers);
 
+        dependencyFilters = Collections
+                .unmodifiableCollection(createDependencyFilters());
         initialized = true;
     }
 
@@ -1429,6 +1432,54 @@ public abstract class VaadinService implements Serializable {
         return requestHandlers;
     }
 
+    /**
+     * Constructs the list of resource dependency filters to use for the
+     * application.
+     * <p>
+     * The filters can freely update the dependencies in any way they see fit
+     * (bundle, rewrite, merge).
+     * <p>
+     * By default all filters found using the service loader are added to the
+     * list.
+     * <p>
+     * The filters are called in the order the service loader returns the
+     * filters, which is undefined. If you need a specific order, you can
+     * override this method and alter the order.
+     *
+     * @since
+     * @return the list of dependency filters to use for filtering resources,
+     *         not null
+     * @throws ServiceException
+     *             if something went wrong while determining the filters
+     *
+     */
+    protected List<DependencyFilter> createDependencyFilters()
+            throws ServiceException {
+        ArrayList<DependencyFilter> filters = new ArrayList<>();
+        ServiceLoader<DependencyFilter> loader = ServiceLoader
+                .load(DependencyFilter.class, getClassLoader());
+        loader.iterator().forEachRemaining(filters::add);
+
+        return filters;
+    }
+
+    /**
+     * Gets the filters which all resource dependencies are passed through
+     * before being sent to the client for loading.
+     *
+     * @see #createDependencyFilters()
+     *
+     * @since
+     * @return the dependency filters to pass resources dependencies through
+     *         before loading
+     */
+    public Iterable<DependencyFilter> getDependencyFilters() {
+        if (dependencyFilters == null) {
+            return Collections.emptyList();
+        }
+        return dependencyFilters;
+    }
+
     /**
      * Handles the incoming request and writes the response into the response
      * object. Uses {@link #getRequestHandlers()} for handling the request.

server/src/main/java/com/vaadin/server/communication/UidlWriter.java

@@ -30,6 +30,7 @@ import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import com.vaadin.server.ClientConnector;
+import com.vaadin.server.DependencyFilter.FilterContext;
 import com.vaadin.server.JsonPaintTarget;
 import com.vaadin.server.LegacyCommunicationManager;
 import com.vaadin.server.LegacyCommunicationManager.ClientCache;
@@ -283,7 +284,8 @@ public class UidlWriter implements Serializable {
             });
 
             List<Dependency> dependencies = Dependency
-                    .findDependencies(newConnectorTypes, manager);
+                    .findAndFilterDependencies(newConnectorTypes, manager,
+                            new FilterContext(session));
 
             // Include dependencies in output if there are any
             if (!dependencies.isEmpty()) {

server/src/main/java/com/vaadin/ui/Dependency.java

@@ -24,7 +24,10 @@ import com.vaadin.annotations.HtmlImport;
 import com.vaadin.annotations.JavaScript;
 import com.vaadin.annotations.StyleSheet;
 import com.vaadin.server.ClientConnector;
+import com.vaadin.server.DependencyFilter;
+import com.vaadin.server.DependencyFilter.FilterContext;
 import com.vaadin.server.LegacyCommunicationManager;
+import com.vaadin.server.VaadinService;
 
 /**
  * Represents a stylesheet or JavaScript to include on the page.
@@ -152,7 +155,7 @@ public class Dependency implements Serializable {
      * @param manager
      *            a reference to the communication manager which tracks
      *            dependencies
-     * @return
+     * @return the list of found dependencies
      */
     @SuppressWarnings("deprecation")
     public static List<Dependency> findDependencies(
@@ -172,4 +175,32 @@ public class Dependency implements Serializable {
         return dependencies;
     }
 
+    /**
+     * Finds all the URLs defined for the given classes, registers the URLs to
+     * the communication manager, passes the registered dependencies through any
+     * defined filters and returns the filtered collection of dependencies to
+     * load.
+     *
+     * @since
+     * @param connectorTypes
+     *            the collection of connector classes to scan
+     * @param manager
+     *            a reference to the communication manager which tracks
+     *            dependencies
+     * @param context
+     *            the context information for the filtering operation
+     * @return the list of found and filtered dependencies
+     */
+    public static List<Dependency> findAndFilterDependencies(
+            List<Class<? extends ClientConnector>> connectorTypes,
+            LegacyCommunicationManager manager, FilterContext context) {
+        List<Dependency> dependencies = findDependencies(connectorTypes,
+                manager);
+        VaadinService service = context.getService();
+        for (DependencyFilter filter : service.getDependencyFilters()) {
+            dependencies = filter.filter(dependencies, context);
+        }
+        return dependencies;
+    }
+
 }

test/dependency-rewrite-addon/pom.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>com.vaadin</groupId>
+        <artifactId>vaadin-test</artifactId>
+        <version>8.1-SNAPSHOT</version>
+    </parent>
+    <artifactId>vaadin-test-dependency-rewrite-addon</artifactId>
+    <packaging>jar</packaging>
+    <dependencies>
+        <dependency>
+            <groupId>com.vaadin</groupId>
+            <artifactId>vaadin-test-widget-set-testutil</artifactId>
+        </dependency>
+    </dependencies>
+
+</project>

test/dependency-rewrite-addon/src/main/java/com/vaadin/test/dependencyrewriteaddon/RewriteJQueryFilter.java

@@ -0,0 +1,28 @@
+package com.vaadin.test.dependencyrewriteaddon;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Locale;
+
+import com.vaadin.server.DependencyFilter;
+import com.vaadin.ui.Dependency;
+import com.vaadin.ui.Dependency.Type;
+
+public class RewriteJQueryFilter implements DependencyFilter {
+
+    @Override
+    public List<Dependency> filter(List<Dependency> dependencies,
+            FilterContext filterContext) {
+        List<Dependency> filtered = new ArrayList<>();
+        for (Dependency dependency : dependencies) {
+            if (dependency.getType() == Type.JAVASCRIPT && dependency.getUrl()
+                    .toLowerCase(Locale.ENGLISH).contains("jquery")) {
+                filtered.add(
+                        new Dependency(Type.JAVASCRIPT, "vaadin://jquery.js"));
+            } else {
+                filtered.add(dependency);
+            }
+        }
+        return filtered;
+    }
+}

test/dependency-rewrite-addon/src/main/resources/META-INF/services/com.vaadin.server.DependencyFilter

@@ -0,0 +1 @@
+com.vaadin.test.dependencyrewriteaddon.RewriteJQueryFilter

test/dependency-rewrite/pom.xml

@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>com.vaadin</groupId>
+        <artifactId>vaadin-test</artifactId>
+        <version>8.1-SNAPSHOT</version>
+    </parent>
+    <artifactId>vaadin-test-dependency-rewrite</artifactId>
+    <packaging>war</packaging>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.vaadin</groupId>
+            <artifactId>vaadin-test-widget-set-testutil</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>com.vaadin</groupId>
+            <artifactId>vaadin-client-compiled</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>com.vaadin</groupId>
+            <artifactId>vaadin-test-dependency-rewrite-addon</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+
+    </dependencies>
+
+</project>

test/dependency-rewrite/src/main/java/com/vaadin/test/dependencyrewrite/ApplicationDependencyFilter.java

@@ -0,0 +1,26 @@
+package com.vaadin.test.dependencyrewrite;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import com.vaadin.server.DependencyFilter;
+import com.vaadin.ui.Dependency;
+
+public class ApplicationDependencyFilter implements DependencyFilter {
+
+    @Override
+    public List<Dependency> filter(List<Dependency> dependencies,
+            FilterContext filterContext) {
+        List<Dependency> filtered = new ArrayList<>();
+        for (Dependency dependency : dependencies) {
+            if (dependency.getUrl().startsWith("vaadin://")) {
+                filtered.add(new Dependency(dependency.getType(), dependency
+                        .getUrl().replace("vaadin://", "vaadin://sub/")));
+            } else {
+                filtered.add(dependency);
+            }
+        }
+        return filtered;
+    }
+
+}

test/dependency-rewrite/src/main/java/com/vaadin/test/dependencyrewrite/DependencyDynamicUI.java

@@ -0,0 +1,34 @@
+package com.vaadin.test.dependencyrewrite;
+
+import com.vaadin.annotations.JavaScript;
+import com.vaadin.server.VaadinRequest;
+import com.vaadin.ui.Label;
+import com.vaadin.ui.UI;
+import com.vaadin.ui.VerticalLayout;
+
+public class DependencyDynamicUI extends UI {
+
+    @JavaScript("http://jquery.com/jquery-1.2.3.js")
+    public static class MyJqueryLabel extends Label {
+        public MyJqueryLabel() {
+            super("MyJqueryLabel");
+        }
+    }
+
+    @JavaScript("vaadin://jquery-33.3.3.js")
+    public static class MyJqueryLabel2 extends Label {
+        public MyJqueryLabel2() {
+            super("MyJqueryLabel2");
+        }
+    }
+
+    @Override
+    protected void init(VaadinRequest request) {
+        VerticalLayout layout = new VerticalLayout();
+        layout.addComponent(new MyJqueryLabel());
+        layout.addComponent(new MyJqueryLabel2());
+
+        setContent(layout);
+    }
+
+}

test/dependency-rewrite/src/main/java/com/vaadin/test/dependencyrewrite/DependencyInitialUI.java

@@ -0,0 +1,21 @@
+package com.vaadin.test.dependencyrewrite;
+
+import com.vaadin.annotations.JavaScript;
+import com.vaadin.server.VaadinRequest;
+import com.vaadin.test.dependencyrewrite.DependencyDynamicUI.MyJqueryLabel;
+import com.vaadin.ui.UI;
+import com.vaadin.ui.VerticalLayout;
+
+@JavaScript("http://jquery.com/jquery-12.2.3.js")
+@JavaScript("vaadin://jquery-323.3.3.js")
+public class DependencyInitialUI extends UI {
+
+    @Override
+    protected void init(VaadinRequest request) {
+        VerticalLayout layout = new VerticalLayout();
+        layout.addComponent(new MyJqueryLabel());
+
+        setContent(layout);
+    }
+
+}

test/dependency-rewrite/src/main/java/com/vaadin/test/dependencyrewrite/MyService.java

@@ -0,0 +1,27 @@
+package com.vaadin.test.dependencyrewrite;
+
+import java.util.List;
+
+import com.vaadin.server.DependencyFilter;
+import com.vaadin.server.DeploymentConfiguration;
+import com.vaadin.server.ServiceException;
+import com.vaadin.server.VaadinServlet;
+import com.vaadin.server.VaadinServletService;
+
+public class MyService extends VaadinServletService {
+
+    public MyService(VaadinServlet servlet,
+            DeploymentConfiguration deploymentConfiguration)
+            throws ServiceException {
+        super(servlet, deploymentConfiguration);
+    }
+
+    @Override
+    protected List<DependencyFilter> createDependencyFilters()
+            throws ServiceException {
+        List<DependencyFilter> list = super.createDependencyFilters();
+        list.add(new ApplicationDependencyFilter());
+        return list;
+    }
+
+}

test/dependency-rewrite/src/main/java/com/vaadin/test/dependencyrewrite/MyUIProvider.java

@@ -0,0 +1,22 @@
+package com.vaadin.test.dependencyrewrite;
+
+import com.vaadin.server.UIClassSelectionEvent;
+import com.vaadin.server.UIProvider;
+import com.vaadin.ui.UI;
+
+public class MyUIProvider extends UIProvider {
+
+    @Override
+    public Class<? extends UI> getUIClass(UIClassSelectionEvent event) {
+        String url = event.getRequest().getPathInfo();
+        if (url.contains("/dynamic/")) {
+            return DependencyDynamicUI.class;
+        } else if (url.contains("/initial/")) {
+            return DependencyInitialUI.class;
+        } else {
+            return null;
+        }
+
+    }
+
+}

test/dependency-rewrite/src/main/java/com/vaadin/test/dependencyrewrite/MyUIServlet.java

@@ -0,0 +1,22 @@
+package com.vaadin.test.dependencyrewrite;
+
+import javax.servlet.annotation.WebInitParam;
+import javax.servlet.annotation.WebServlet;
+
+import com.vaadin.server.DeploymentConfiguration;
+import com.vaadin.server.ServiceException;
+import com.vaadin.server.VaadinServlet;
+import com.vaadin.server.VaadinServletService;;
+
+@WebServlet(urlPatterns = {
+        "/*" }, name = "MyUIServlet", asyncSupported = true, initParams = @WebInitParam(name = "UIProvider", value = "com.vaadin.test.dependencyrewrite.MyUIProvider"))
+public class MyUIServlet extends VaadinServlet {
+    @Override
+    protected VaadinServletService createServletService(
+            DeploymentConfiguration deploymentConfiguration)
+            throws ServiceException {
+        MyService service = new MyService(this, deploymentConfiguration);
+        service.init();
+        return service;
+    }
+}

test/dependency-rewrite/src/main/webapp/VAADIN/sub/jquery.js

@@ -0,0 +1,5 @@
+if (!window.jqueryLoaded) {
+	window.jqueryLoaded = 1;
+} else {
+	window.jqueryLoaded++;
+}

test/dependency-rewrite/src/test/java/com/vaadin/test/dependencyrewrite/DependencyFilterIT.java

@@ -0,0 +1,29 @@
+package com.vaadin.test.dependencyrewrite;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.openqa.selenium.JavascriptExecutor;
+import org.openqa.selenium.phantomjs.PhantomJSDriver;
+
+import com.vaadin.testbench.TestBenchTestCase;
+
+public class DependencyFilterIT extends TestBenchTestCase {
+
+    @Test
+    public void dynamicallyAddedResources() {
+        setDriver(new PhantomJSDriver());
+        getDriver().get("http://localhost:8080/dynamic/");
+        Assert.assertEquals(1L, ((JavascriptExecutor) getDriver())
+                .executeScript("return window.jqueryLoaded"));
+    }
+
+    @Test
+    public void initiallyLoadedResources() {
+        setDriver(new PhantomJSDriver());
+        getDriver().get("http://localhost:8080/initial/");
+        // 2 because of https://github.com/vaadin/framework/issues/9181
+        Assert.assertEquals(2L, ((JavascriptExecutor) getDriver())
+                .executeScript("return window.jqueryLoaded"));
+    }
+
+}

test/pom.xml

@@ -107,6 +107,8 @@
         <module>servlet-containers/jsp-integration</module>
         <module>bean-api-validation</module>
         <module>bean-impl-validation</module>
+        <module>dependency-rewrite-addon</module>
+        <module>dependency-rewrite</module>
     </modules>
 
     <build>