SAK-50802 Lessons creates a Lessons links on navigation when there ar…

…e no items in an export (#13223)

lessonbuilder/tool/src/java/org/sakaiproject/lessonbuildertool/service/LessonBuilderEntityProducer.java

@@ -1272,7 +1272,27 @@ public String merge(String siteId, Element root, String archivePath, String from
 			 String pagePosition = element.getAttribute("pagePosition");
 			 String pageVisibility = element.getAttribute("pageVisibility");
 
-			 if(toolTitle != null) {
+			 NodeList lessonBuilderTools = root.getElementsByTagName("lessonbuilder");
+			 boolean lessonHasContent = false;
+
+			 for (int toolIndex = 0; toolIndex < lessonBuilderTools.getLength() && !lessonHasContent; toolIndex++) {
+				 Node lessonBuilderNode = lessonBuilderTools.item(toolIndex);
+				 if (lessonBuilderNode.getNodeType() == Node.ELEMENT_NODE) {
+					 Element lessonBuilderElement = (Element) lessonBuilderNode;
+					 NodeList lessonPages = lessonBuilderElement.getElementsByTagName("page");
+
+					 for (int pageIndex = 0; pageIndex < lessonPages.getLength() && !lessonHasContent; pageIndex++) {
+						 Element currentPage = (Element) lessonPages.item(pageIndex);
+						 NodeList pageItems = currentPage.getElementsByTagName("item");
+
+						 if (pageItems != null && pageItems.getLength() > 0) {
+							 lessonHasContent = true;
+						 }
+					 }
+				 }
+			 }
+
+			 if(toolTitle != null && lessonHasContent) {
 			     Tool tr = toolManager.getTool(LessonBuilderConstants.TOOL_ID);
 			     SitePage page = null;
 			     ToolConfiguration tool = null;