fix: avoid manipulate absolute stream resource URL in web-component m…

…ode (#13296) (CP: 2.7) (#13306)

* fix: avoid manipulate absolute stream resource URL in web-component mode  (#13296)

In web-component mode resource URLs are always prefixed by serviceUrl,
but sometimes the URL is already absolute (e.g. in Liferay).
With this change absolute URLs are used as-is also in web-component mode.

Fixes #13288

* test: fixed StreamResource test in compatibility mode

Co-authored-by: Marco Collovati <marco@vaadin.com>

flow-client/src/main/java/com/vaadin/client/WidgetUtil.java

@@ -74,6 +74,22 @@ public static String getAbsoluteUrl(String url) {
         return a.getHref();
     }
 
+    /**
+     * Detects if an URL is absolute.
+     *
+     * URLs wihtout schema but starting with double slashes (e.g. //myhost/path}
+     * are considered absolute.
+     *
+     * @param url
+     *            a string with the URL to check
+     * @return {@literal true} if the url is absolute, otherwise
+     *         {@literal false}.
+     */
+    public static native boolean isAbsoluteUrl(String url)
+    /*-{
+        return !!url.match(/^(?:[a-zA-Z]+:)?\/\//);
+    }-*/;
+
     /**
      * Anything in, anything out. It's JavaScript after all. This method just
      * makes the Java compiler accept the fact.

flow-client/src/main/java/com/vaadin/client/flow/binding/SimpleElementBindingStrategy.java

@@ -1481,7 +1481,8 @@ private static void updateAttributeValue(
                                 + attribute + "' but it has no "
                                 + NodeProperties.URI_ATTRIBUTE + " key";
                 String uri = object.getString(NodeProperties.URI_ATTRIBUTE);
-                if (configuration.isWebComponentMode()) {
+                if (configuration.isWebComponentMode()
+                        && !WidgetUtil.isAbsoluteUrl(uri)) {
                     String baseUri = configuration.getServiceUrl();
                     baseUri = baseUri.endsWith("/") ? baseUri : baseUri + "/";
                     WidgetUtil.updateAttribute(element, attribute,

flow-tests/test-embedding/embedding-test-assets/src/main/java/com/vaadin/flow/webcomponent/StreamResourceExporter.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright 2000-2022 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.webcomponent;
+
+import java.nio.charset.StandardCharsets;
+
+import com.vaadin.flow.component.WebComponentExporter;
+import com.vaadin.flow.component.html.Anchor;
+import com.vaadin.flow.component.html.Div;
+import com.vaadin.flow.component.webcomponent.WebComponent;
+import com.vaadin.flow.server.StreamResource;
+
+public class StreamResourceExporter extends WebComponentExporter<Div> {
+
+    public StreamResourceExporter() {
+        super("vaadin-stream-resource");
+    }
+
+    @Override
+    protected void configureInstance(WebComponent<Div> webComponent,
+            Div component) {
+        StreamResource relativeUrl = createStreamResource("relativeURL");
+        Anchor relativeLink = new Anchor(relativeUrl, "Relative Link");
+        relativeLink.setId("relativeLink");
+
+        StreamResource absoluteUrl = createStreamResource("absoluteURL");
+        Anchor absoluteLink = new Anchor(absoluteUrl, "Absolute Link");
+        absoluteLink.setId("absoluteLink");
+
+        StreamResource schemalessUrl = createStreamResource(
+                "absoluteURLschemaless");
+        Anchor schemalessLink = new Anchor(schemalessUrl, "Schemaless Link");
+        schemalessLink.setId("schemalessLink");
+
+        component.add(relativeLink, absoluteLink, schemalessLink);
+    }
+
+    private StreamResource createStreamResource(String type) {
+        return new StreamResource(type + ".txt", (stream, session) -> stream
+                .write(type.getBytes(StandardCharsets.UTF_8)));
+    }
+
+}

flow-tests/test-embedding/embedding-test-assets/src/main/java/com/vaadin/flow/webcomponent/servlets/CustomStreamResourceRegistryServlet.java

@@ -0,0 +1,77 @@
+/*
+ * Copyright 2000-2022 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.webcomponent.servlets;
+
+import javax.servlet.annotation.WebServlet;
+
+import java.net.URI;
+
+import com.vaadin.flow.function.DeploymentConfiguration;
+import com.vaadin.flow.server.AbstractStreamResource;
+import com.vaadin.flow.server.ServiceException;
+import com.vaadin.flow.server.StreamResourceRegistry;
+import com.vaadin.flow.server.VaadinRequest;
+import com.vaadin.flow.server.VaadinServlet;
+import com.vaadin.flow.server.VaadinServletService;
+import com.vaadin.flow.server.VaadinSession;
+
+@WebServlet(urlPatterns = { "/vaadin-stream-resources/*",
+        "/vaadin-stream-resources-absolute/*" }, asyncSupported = true)
+public class CustomStreamResourceRegistryServlet extends VaadinServlet {
+
+    @Override
+    protected VaadinServletService createServletService(
+            DeploymentConfiguration deploymentConfiguration)
+            throws ServiceException {
+        VaadinServletService service = new VaadinServletService(this,
+                deploymentConfiguration) {
+
+            @Override
+            protected VaadinSession createVaadinSession(VaadinRequest request) {
+                return new VaadinSession(this) {
+                    @Override
+                    protected StreamResourceRegistry createStreamResourceRegistry() {
+                        return new StreamResourceRegistry(this) {
+                            @Override
+                            public URI getTargetURI(
+                                    AbstractStreamResource resource) {
+                                URI targetURI = super.getTargetURI(resource);
+                                if (resource.getName()
+                                        .contains("absoluteURL")) {
+                                    String baseURL = getCurrentServletRequest()
+                                            .getRequestURL().toString()
+                                            .replaceFirst(
+                                                    "(/vaadin-stream-resources)/.*",
+                                                    "$1-absolute/");
+                                    if (resource.getName()
+                                            .contains("schemaless")) {
+                                        baseURL = baseURL.replaceFirst(
+                                                "^https?://", "//");
+                                    }
+                                    return URI.create(baseURL)
+                                            .resolve(targetURI);
+                                }
+                                return targetURI;
+                            }
+                        };
+                    }
+                };
+            }
+        };
+        service.init();
+        return service;
+    }
+}

flow-tests/test-embedding/embedding-test-assets/src/test/java/com/vaadin/flow/webcomponent/StreamResourceIT.java

@@ -0,0 +1,86 @@
+/*
+ * Copyright 2000-2022 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.webcomponent;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.openqa.selenium.By;
+
+import com.vaadin.flow.testutil.ChromeBrowserTest;
+import com.vaadin.testbench.TestBenchElement;
+
+public class StreamResourceIT extends ChromeBrowserTest {
+
+    @Override
+    protected String getTestPath() {
+        return Constants.PAGE_CONTEXT + "/streamResource.html";
+    }
+
+    @Test
+    public void absoluteUrlsAreNotModified() {
+        open();
+
+        waitForElementVisible(By.tagName("vaadin-stream-resource"));
+
+        TestBenchElement downloadLink = $("vaadin-stream-resource").first()
+                .$("a").id("absoluteLink");
+
+        String url = downloadLink.getAttribute("href");
+        Assert.assertTrue(
+                "Url is not generated by custom StreamResourceRegistry",
+                url.contains("/vaadin-stream-resources-absolute/"));
+        Assert.assertEquals(
+                "Absolute url has been prefixed with other content: " + url, 0,
+                url.lastIndexOf("http://"));
+    }
+
+    @Test
+    public void schemaLessUrlsAreNotModified() {
+        open();
+
+        waitForElementVisible(By.tagName("vaadin-stream-resource"));
+
+        TestBenchElement downloadLink = $("vaadin-stream-resource").first()
+                .$("a").id("schemalessLink");
+
+        String url = downloadLink.getAttribute("href");
+        Assert.assertTrue(
+                "Url is not generated by custom StreamResourceRegistry",
+                url.contains("/vaadin-stream-resources-absolute/"));
+        Assert.assertEquals(
+                "Absolute url has been prefixed with other content: " + url, 0,
+                url.lastIndexOf("http://"));
+    }
+
+    @Test
+    public void relativeUrlsArePrefixedWithServiceUrl() {
+        open();
+
+        waitForElementVisible(By.tagName("vaadin-stream-resource"));
+
+        TestBenchElement downloadLink = $("vaadin-stream-resource").first()
+                .$("a").id("relativeLink");
+
+        String url = downloadLink.getAttribute("href");
+        Assert.assertTrue(
+                "Url is not generated by custom StreamResourceRegistry",
+                url.contains("/vaadin-stream-resources/"));
+        Assert.assertEquals(
+                "Absolute url has been prefixed with other content: " + url, 0,
+                url.lastIndexOf("http://"));
+    }
+
+}

flow-tests/test-embedding/webapp/compatibility-dev/streamResource.html

@@ -0,0 +1,31 @@
+<!--
+  ~ Copyright 2000-2022 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.
+  -->
+
+<!doctype html>
+
+<head>
+  <script type="text/javascript" src="/frontend/bower_components/webcomponentsjs/webcomponents-loader.js"></script>
+  <link rel="import" href="/vaadin-stream-resources/web-component/vaadin-stream-resource.html">
+</head>
+
+<body>
+  <p>
+    StreamResource in Web components
+  </p>
+
+  <vaadin-stream-resource></vaadin-stream-resource>
+
+</body>

flow-tests/test-embedding/webapp/compatibility-prod/streamResource.html

@@ -0,0 +1,31 @@
+<!--
+  ~ Copyright 2000-2022 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.
+  -->
+
+<!doctype html>
+
+<head>
+  <script type="text/javascript"
+          src="/vaadin-stream-resources/web-component/vaadin-stream-resource.html"></script>
+</head>
+
+<body>
+  <p>
+    StreamResource in Web components
+  </p>
+
+  <vaadin-stream-resource></vaadin-stream-resource>
+
+</body>

flow-tests/test-embedding/webapp/npm/streamResource.html

@@ -0,0 +1,31 @@
+<!--
+  ~ Copyright 2000-2022 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.
+  -->
+
+<!doctype html>
+
+<head>
+  <script type='module'
+          src='/vaadin-stream-resources/web-component/vaadin-stream-resource.js'></script>
+</head>
+
+<body>
+  <p>
+    StreamResource in Web components
+  </p>
+
+  <vaadin-stream-resource></vaadin-stream-resource>
+
+</body>