Fix anchor links handling with destinations on elements handled by SpanTagWorker

DEVSIX-2774

Author: yulian-gaponenko

src/main/java/com/itextpdf/html2pdf/LogMessageConstant.java

@@ -49,6 +49,7 @@ public final class LogMessageConstant {
 
     /** The Constant ACROFORM_NOT_SUPPORTED_FOR_SELECT. */
     public static final String ACROFORM_NOT_SUPPORTED_FOR_SELECT = "AcroForm fields creation for select fields (ComboBoxField and ListBoxField) is not supported. They will be flattened instead.";
+    public static final String ANCHOR_LINK_NOT_HANDLED = "The anchor link was not handled. Could not create a destination for element \"{0}\" with ID \"{1}\", which is processed by \"{2}\" tag worker class.";
     /** The Constant CONTENT_PROPERTY_INVALID. */
     public static final String CONTENT_PROPERTY_INVALID = "Content property \"{0}\" is either invalid or uses unsupported function.";
     /** The Constant CSS_PROPERTY_IN_PERCENTS_NOT_SUPPORTED. */
@@ -111,7 +112,7 @@ public final class LogMessageConstant {
     public static final String TEXT_WAS_NOT_PROCESSED = "Text was not processed: {0}";
     /** The Constant UNABLE_TO_PROCESS_EXTERNAL_CSS_FILE. */
     public static final String UNABLE_TO_PROCESS_EXTERNAL_CSS_FILE = "Unable to process external css file";
-    /** The Constant UNABLE_TO_PROCESS_IMAGE_AS_SVG*/
+    /** The Constant UNABLE_TO_PROCESS_IMAGE_AS_SVG */
     public static final String UNABLE_TO_PROCESS_IMAGE_AS_SVG = "Unable to process image found at {0} as an SVG";
     /** The Constant UNABLE_TO_RESOLVE_COUNTER. */
     public static final String UNABLE_TO_RESOLVE_COUNTER = "Unable to resolve counter \"{0}\"";

src/main/java/com/itextpdf/html2pdf/attach/impl/LinkContext.java

@@ -43,6 +43,7 @@ This file is part of the iText (R) project.
 package com.itextpdf.html2pdf.attach.impl;
 
 import com.itextpdf.html2pdf.html.AttributeConstants;
+import com.itextpdf.html2pdf.html.TagConstants;
 import com.itextpdf.styledxmlparser.node.IElementNode;
 import com.itextpdf.styledxmlparser.node.INode;
 
@@ -91,9 +92,12 @@ public LinkContext scanForIds(INode root) {
         while (!stk.isEmpty()) {
             INode n = stk.pop();
             if (n instanceof IElementNode) {
-                IElementNode n2 = (IElementNode) n;
-                if (n2.name().equals(AttributeConstants.a) && n2.getAttribute(AttributeConstants.HREF) != null && n2.getAttribute(AttributeConstants.HREF).startsWith("#")) {
-                    linkDestinations.add(n2.getAttribute(AttributeConstants.HREF).substring(1));
+                IElementNode elem = (IElementNode) n;
+                if (TagConstants.A.equals(elem.name())) {
+                    String href = elem.getAttribute(AttributeConstants.HREF);
+                    if (href != null && href.startsWith("#")){
+                        linkDestinations.add(href.substring(1));
+                    }
                 }
             }
             if (!n.childNodes().isEmpty()) {

src/main/java/com/itextpdf/html2pdf/attach/util/LinkHelper.java

@@ -42,8 +42,11 @@ This file is part of the iText (R) project.
  */
 package com.itextpdf.html2pdf.attach.util;
 
+import com.itextpdf.html2pdf.LogMessageConstant;
 import com.itextpdf.html2pdf.attach.ITagWorker;
 import com.itextpdf.html2pdf.attach.ProcessorContext;
+import com.itextpdf.html2pdf.attach.impl.tags.SpanTagWorker;
+import com.itextpdf.io.util.MessageFormatUtil;
 import com.itextpdf.kernel.geom.Rectangle;
 import com.itextpdf.kernel.pdf.PdfArray;
 import com.itextpdf.kernel.pdf.action.PdfAction;
@@ -56,6 +59,9 @@ This file is part of the iText (R) project.
 import com.itextpdf.layout.property.Property;
 import com.itextpdf.html2pdf.html.AttributeConstants;
 import com.itextpdf.styledxmlparser.node.IElementNode;
+import java.util.List;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * Helper class for links.
@@ -99,22 +105,33 @@ public static void applyLinkAnnotation(IPropertyContainer container, String url)
      * @param context   the Processor context
      */
     public static void createDestination(ITagWorker tagWorker, IElementNode element, ProcessorContext context) {
-        if (element.getAttribute(AttributeConstants.ID) == null)
-            return;
-
-        if (tagWorker == null)
+        String id = element.getAttribute(AttributeConstants.ID);
+        if (id == null)
             return;
 
-        IPropertyContainer propertyContainer = tagWorker.getElementResult();
-        if (propertyContainer == null)
+        if (!context.getLinkContext().isUsedLinkDestination(id)) {
             return;
+        }
 
-        // get id
-        String id = element.getAttribute(AttributeConstants.ID);
+        IPropertyContainer propertyContainer = null;
+        if (tagWorker != null) {
+            if (tagWorker instanceof SpanTagWorker) {
+                List<IPropertyContainer> spanElements = ((SpanTagWorker) tagWorker).getAllElements();
+                if (!spanElements.isEmpty()) {
+                    propertyContainer = spanElements.get(0);
+                }
+            } else {
+                propertyContainer = tagWorker.getElementResult();
+            }
+        }
 
-        // set property
-        if (context.getLinkContext().isUsedLinkDestination(id)) {
-            propertyContainer.setProperty(Property.DESTINATION, id);
+        if (propertyContainer == null) {
+            Logger logger = LoggerFactory.getLogger(LinkHelper.class);
+            String tagWorkerClassName = tagWorker != null ? tagWorker.getClass().getName() : "null";
+            logger.warn(MessageFormatUtil.format(LogMessageConstant.ANCHOR_LINK_NOT_HANDLED, element.name(), id, tagWorkerClassName));
+            return;
         }
+
+        propertyContainer.setProperty(Property.DESTINATION, id);
     }
 }

src/test/java/com/itextpdf/html2pdf/element/LinkTest.java

@@ -170,4 +170,11 @@ public void linkTest12() throws IOException, InterruptedException {
         }
         Assert.assertNull(new CompareTool().compareByContent(destinationFolder + "linkTest12.pdf", sourceFolder + "cmp_linkTest12.pdf", destinationFolder, "diff12_"));
     }
+
+    @Test
+    public void anchorLinkToSpanTest01() throws IOException, InterruptedException {
+        String fileName = "anchorLinkToSpanTest01";
+        HtmlConverter.convertToPdf(new File(sourceFolder + fileName + ".html"), new File(destinationFolder + fileName + ".pdf"));
+        Assert.assertNull(new CompareTool().compareByContent(destinationFolder + fileName + ".pdf", sourceFolder + "cmp_" + fileName + ".pdf", destinationFolder));
+    }
 }

src/test/resources/com/itextpdf/html2pdf/element/LinkTest/anchorLinkToSpanTest01.html

@@ -0,0 +1,13 @@
+<html>
+<body>
+
+<a id="main_q" href="#Welsh_Corgi">Who's a good boy?</a>
+<p style="page-break-before: always;">
+	<span id="Welsh_Corgi">corgi</span>
+	<a href="#main_q">Back to main question!</a>
+</p>
+
+
+</body>
+</html>
+