Merge pull request #1456 from scireum/feature/jvo/OX-10783-Automagic-…

…URL-Fixing

PDF Rendering: Automagic Rewriting of Plain URLs

pom.xml

@@ -14,7 +14,7 @@
     <description>Provides a modern and scalable web server as SIRIUS module</description>
 
     <properties>
-        <sirius.kernel>dev-43.0.0</sirius.kernel>
+        <sirius.kernel>dev-43.1.0</sirius.kernel>
     </properties>
 
     <repositories>

src/main/java/sirius/web/templates/pdf/ImageReplacedElementFactory.java

@@ -21,6 +21,7 @@
 import sirius.web.templates.pdf.handlers.PdfReplaceHandler;
 
 import java.util.List;
+import java.util.Optional;
 
 /**
  * Used by the XHTMLRenderer (creating PDFs) to replace img elements by their referenced image.
@@ -51,27 +52,27 @@ public ReplacedElement createReplacedElement(LayoutContext layoutContext,
                                                  UserAgentCallback userAgentCallback,
                                                  int cssWidth,
                                                  int cssHeight) {
-        Element e = box.getElement();
-        if (e == null) {
+        Element element = box.getElement();
+        if (element == null) {
             return null;
         }
 
-        String nodeName = e.getNodeName();
+        String nodeName = element.getNodeName();
         if (!TAG_TYPE_IMG.equals(nodeName)) {
             return super.createReplacedElement(layoutContext, box, userAgentCallback, cssWidth, cssHeight);
         }
 
-        String src = e.getAttribute(ATTR_SRC);
-        if (Strings.isEmpty(src)) {
+        String source = rewriteLegacyUrl(element.getAttribute(ATTR_SRC));
+        if (Strings.isEmpty(source)) {
             return super.createReplacedElement(layoutContext, box, userAgentCallback, cssWidth, cssHeight);
         }
 
         try {
-            String protocol = Strings.split(src, "://").getFirst();
+            String protocol = Strings.split(source, "://").getFirst();
             PdfReplaceHandler handler = findHandler(protocol);
-            return new AsyncLoadedImageElement(handler, userAgentCallback, src, cssWidth, cssHeight);
-        } catch (Exception ex) {
-            Exceptions.handle(ex);
+            return new AsyncLoadedImageElement(handler, userAgentCallback, source, cssWidth, cssHeight);
+        } catch (Exception exception) {
+            Exceptions.handle(exception);
         }
 
         return super.createReplacedElement(layoutContext, box, userAgentCallback, cssWidth, cssHeight);
@@ -85,4 +86,15 @@ private PdfReplaceHandler findHandler(String protocol) {
                                "No handler for protocol '%s' could be found",
                                protocol)));
     }
+
+    private String rewriteLegacyUrl(String url) {
+        for (PdfReplaceHandler handler : handlers) {
+            Optional<String> rewrittenUrl = handler.tryRewritePlainUrl(url);
+            if (rewrittenUrl.isPresent()) {
+                return rewrittenUrl.get();
+            }
+        }
+
+        return url;
+    }
 }

src/main/java/sirius/web/templates/pdf/handlers/PdfReplaceHandler.java

@@ -21,6 +21,7 @@
 import javax.annotation.Nullable;
 import java.io.IOException;
 import java.net.URL;
+import java.util.Optional;
 
 /**
  * Represents a image replace handler that is used by {@link sirius.web.templates.pdf.ImageReplacedElementFactory} to
@@ -34,6 +35,16 @@ public int getPriority() {
         return Priorized.DEFAULT_PRIORITY;
     }
 
+    /**
+     * Attempts to rewrite a plain URL to a PDF-compatible one.
+     *
+     * @param url the plain URL to rewrite
+     * @return an optional containing the new URL if the plain URL could be rewritten, an empty optional otherwise
+     */
+    public Optional<String> tryRewritePlainUrl(String url) {
+        return Optional.empty();
+    }
+
     /**
      * Determines if this handler can resolve a URI with the given protocol.
      *
@@ -119,7 +130,10 @@ private Tuple<Integer, Integer> computeResizeBox(int cssWidth, int cssHeight, FS
     }
 
     @Nonnull
-    private static Tuple<Integer, Integer> downscaleResource(int cssWidth, int cssHeight, int imageWidth, int imageHeight) {
+    private static Tuple<Integer, Integer> downscaleResource(int cssWidth,
+                                                             int cssHeight,
+                                                             int imageWidth,
+                                                             int imageHeight) {
 
         // First, check if we need to scale down the width
         if (imageWidth > cssWidth) {
@@ -138,7 +152,10 @@ private static Tuple<Integer, Integer> downscaleResource(int cssWidth, int cssHe
     }
 
     @Nonnull
-    private static Tuple<Integer, Integer> upscaleResource(int cssWidth, int cssHeight, int imageWidth, int imageHeight) {
+    private static Tuple<Integer, Integer> upscaleResource(int cssWidth,
+                                                           int cssHeight,
+                                                           int imageWidth,
+                                                           int imageHeight) {
 
         // First, scale up only the width
         imageHeight = cssWidth * imageHeight / imageWidth;

src/main/java/sirius/web/templates/pdf/handlers/ResourcePdfReplaceHandler.java

@@ -11,12 +11,14 @@
 import org.xhtmlrenderer.extend.FSImage;
 import org.xhtmlrenderer.extend.UserAgentCallback;
 import sirius.kernel.commons.Strings;
+import sirius.kernel.di.std.ConfigValue;
 import sirius.kernel.di.std.Part;
 import sirius.kernel.di.std.Register;
 import sirius.web.resources.Resource;
 import sirius.web.resources.Resources;
 
 import javax.annotation.Nullable;
+import java.util.Optional;
 
 /**
  * Resolves resource:// URIs that are referencing {@link Resources} to resized images while maintaining the image
@@ -25,6 +27,9 @@
 @Register
 public class ResourcePdfReplaceHandler extends PdfReplaceHandler {
 
+    @ConfigValue("product.baseUrl")
+    private String productBaseUrl;
+
     @Part
     private Resources resources;
 
@@ -46,4 +51,19 @@ public FSImage resolveUri(String uri, UserAgentCallback userAgentCallback, int c
 
         return null;
     }
+
+    @Override
+    public Optional<String> tryRewritePlainUrl(String url) {
+        if (!url.startsWith(productBaseUrl)) {
+            return Optional.empty();
+        }
+
+        // remap plain asset URLs to the resource:// scheme
+        int indexOfAssets = url.indexOf("/assets/");
+        if (indexOfAssets >= 0) {
+            return Optional.of("resource:/" + url.substring(indexOfAssets));
+        }
+
+        return Optional.empty();
+    }
 }