XWIKI-19270: Add support for performing the PDF export using a browser running...

XWIKI-19270: Add support for performing the PDF export using a browser running in a Docker container
* Fix the empty PDF ToC (look for the job status also on the jobs that are currently in execution)
* Allow only HTTP URLs for printing
* Set the base URL before printing to PDF to make sure the relative URLs in the generated PDF are resolved based on the original URL.

xwiki-platform-core/xwiki-platform-export/xwiki-platform-export-pdf/xwiki-platform-export-pdf-api/src/main/java/org/xwiki/export/pdf/internal/macro/PDFTocMacro.java

@@ -35,6 +35,8 @@
 import org.xwiki.export.pdf.job.PDFExportJobStatus;
 import org.xwiki.export.pdf.job.PDFExportJobStatus.DocumentRenderingResult;
 import org.xwiki.export.pdf.macro.PDFTocMacroParameters;
+import org.xwiki.job.Job;
+import org.xwiki.job.JobExecutor;
 import org.xwiki.job.JobStatusStore;
 import org.xwiki.job.event.status.JobStatus;
 import org.xwiki.rendering.block.Block;
@@ -62,9 +64,18 @@
 @Singleton
 public class PDFTocMacro extends AbstractMacro<PDFTocMacroParameters>
 {
+    /**
+     * Used to retrieve the status of a finished job.
+     */
     @Inject
     private JobStatusStore jobStatusStore;
 
+    /**
+     * Used to retrieve the status of the job currently being executed.
+     */
+    @Inject
+    private JobExecutor jobExecutor;
+
     @Inject
     private DocumentAccessBridge documentAccessBridge;
 
@@ -121,9 +132,18 @@ public boolean supportsInlineMode()
         return false;
     }
 
-    private PDFExportJobStatus getJobStatus(String jobId)
+    private PDFExportJobStatus getJobStatus(String jobIdString)
     {
-        JobStatus jobStatus = this.jobStatusStore.getJobStatus(Arrays.asList(jobId.split("/")));
+        List<String> jobId = Arrays.asList(jobIdString.split("/"));
+
+        JobStatus jobStatus;
+        Job job = this.jobExecutor.getJob(jobId);
+        if (job == null) {
+            jobStatus = this.jobStatusStore.getJobStatus(jobId);
+        } else {
+            jobStatus = job.getStatus();
+        }
+
         if (jobStatus instanceof PDFExportJobStatus) {
             return (PDFExportJobStatus) jobStatus;
         } else {

xwiki-platform-core/xwiki-platform-export/xwiki-platform-export-pdf/xwiki-platform-export-pdf-default/src/main/java/org/xwiki/export/pdf/internal/chrome/ChromeManager.java

@@ -46,6 +46,7 @@
 import org.xwiki.component.phase.Initializable;
 import org.xwiki.component.phase.InitializationException;
 
+import com.github.kklisura.cdt.protocol.commands.DOM;
 import com.github.kklisura.cdt.protocol.commands.Network;
 import com.github.kklisura.cdt.protocol.commands.Page;
 import com.github.kklisura.cdt.protocol.commands.Runtime;
@@ -195,18 +196,26 @@ private void waitForPageReady(Runtime runtime) throws IOException
             /* generatePreview */ false, /* userGesture */ false, /* awaitPromise */ true,
             /* throwOnSideEffect */ false, /* timeout */ REMOTE_DEBUGGING_TIMEOUT * 1000.0, /* disableBreaks */ true,
             /* replMode */ false, /* allowUnsafeEvalBlockedByCSP */ false, /* uniqueContextId */ null);
+        checkEvaluation(evaluate, "Page ready.", "Failed to wait for page to be ready.",
+            "Timeout waiting for page to be ready.");
+    }
+
+    private void checkEvaluation(Evaluate evaluate, Object expectedValue, String evaluationException,
+        String unexpectedValueException) throws IOException
+    {
+        String messageTemplae = "%s Root cause: %s";
         if (evaluate.getExceptionDetails() != null) {
             RemoteObject exception = evaluate.getExceptionDetails().getException();
             Object cause = exception.getDescription();
             if (cause == null) {
-                // When the page ready promise as rejected.
+                // When the exception was thrown as a string or when a promise was rejected.
                 cause = exception.getValue();
             }
-            throw new IOException("Failed to wait for page to be ready. Root cause: " + cause);
+            throw new IOException(String.format(messageTemplae, evaluationException, cause));
         } else {
             RemoteObject result = evaluate.getResult();
-            if (!"Page ready.".equals(result.getValue())) {
-                throw new IOException("Timeout waiting for page to be ready. Root cause: " + result.getValue());
+            if (!Objects.equals(expectedValue, result.getValue())) {
+                throw new IOException(String.format(messageTemplae, unexpectedValueException, result.getValue()));
             }
         }
     }
@@ -365,4 +374,28 @@ private void createBrowserDevToolsService() throws ChromeServiceException
             throw new ChromeServiceException("Failed to connect to the browser web socket.", e);
         }
     }
+
+    /**
+     * Sets the base URL for the page loaded on the specified browser tab.
+     * 
+     * @param tabDevToolsService the developer tools service associated with the target page
+     * @param baseURL the base URL to set
+     */
+    public void setBaseURL(ChromeDevToolsService tabDevToolsService, URL baseURL) throws IOException
+    {
+        Runtime runtime = tabDevToolsService.getRuntime();
+        runtime.enable();
+
+        // Add the BASE tag to the page head. I couldn't find a way to create this node using the DOM domain, so I'm
+        // using JavaScript instead (i.e. the runtime domain).
+        Evaluate evaluate = runtime.evaluate("jQuery('<base/>').prependTo('head').length");
+        checkEvaluation(evaluate, 1, "Failed to insert the BASE tag.", "Unexpected page HTML.");
+
+        DOM dom = tabDevToolsService.getDOM();
+        dom.enable();
+
+        // Look for the BASE tag we just added and set its href attribute in order to change the page base URL.
+        Integer baseNodeId = dom.querySelector(dom.getDocument().getNodeId(), "base");
+        dom.setAttributeValue(baseNodeId, "href", baseURL.toString());
+    }
 }

xwiki-platform-core/xwiki-platform-export/xwiki-platform-export-pdf/xwiki-platform-export-pdf-default/src/main/java/org/xwiki/export/pdf/internal/docker/DockerPDFPrinter.java

@@ -129,15 +129,25 @@ public InputStream print(PDFExportJobRequest request) throws IOException
         URL printPreviewURL = (URL) request.getContext().get(XWikiContextContextStore.PROP_REQUEST_URL);
         this.logger.debug("Printing [{}]", printPreviewURL);
 
+        validatePrintPreviewURL(printPreviewURL);
+
         // The headless Chrome web browser runs inside a Docker container where 'localhost' refers to the container
         // itself. We have to update the domain from the given URL to point to the host running both the XWiki instance
         // and the Docker container.
-        printPreviewURL = new URL(
+        URL dockerPrintPreviewURL = new URL(
             printPreviewURL.toString().replace("://localhost", "://" + this.configuration.getChromeDockerHostName()));
 
         ChromeDevToolsService devToolsService = this.chromeManager.createIncognitoTab();
-        this.chromeManager.setCookies(devToolsService, getCookies(request, printPreviewURL));
-        this.chromeManager.navigate(devToolsService, printPreviewURL);
+        this.chromeManager.setCookies(devToolsService, getCookies(request, dockerPrintPreviewURL));
+        this.chromeManager.navigate(devToolsService, dockerPrintPreviewURL);
+
+        if (!printPreviewURL.toString().equals(dockerPrintPreviewURL.toString())) {
+            // Make sure the relative URLs are resolved based on the original print preview URL otherwise the user won't
+            // be able to open the links from the generated PDF because they use a host name defined only inside the
+            // Docker container where the PDF was generated. See PDFExportConfiguration#getChromeDockerHostName()
+            this.chromeManager.setBaseURL(devToolsService, printPreviewURL);
+        }
+
         return this.chromeManager.printToPDF(devToolsService, () -> {
             this.chromeManager.closeIncognitoTab(devToolsService);
         });
@@ -151,4 +161,16 @@ private List<CookieParam> getCookies(PDFExportJobRequest request, URL printPrevi
         cookies.forEach(cookie -> cookie.setUrl(printPreviewURL.toString()));
         return cookies;
     }
+
+    private void validatePrintPreviewURL(URL printPreviewURL) throws IOException
+    {
+        if (printPreviewURL == null) {
+            throw new IOException("Print preview URL missing.");
+        }
+
+        String protocol = printPreviewURL.getProtocol();
+        if (!"http".equals(protocol) && !"https".equals(protocol)) {
+            throw new IOException(String.format("Unsupported protocol [%s].", protocol));
+        }
+    }
 }