feat: #598 (#689)

src/main/java/run/halo/app/core/freemarker/tag/CategoryTagDirective.java

@@ -46,6 +46,9 @@ public class CategoryTagDirective implements TemplateDirectiveModel {
                 case "list":
                     env.setVariable("categories", builder.build().wrap(postCategoryService.listCategoryWithPostCountDto(Sort.by(DESC, "createTime"))));
                     break;
+                case "tree":
+                    env.setVariable("categories", builder.build().wrap(categoryService.listAsTree(Sort.by(DESC, "createTime"))));
+                    break;
                 case "listByPostId":
                     Integer postId = Integer.parseInt(params.get("postId").toString());
                     List<Category> categories = postCategoryService.listCategoriesBy(postId);

src/main/java/run/halo/app/service/impl/CategoryServiceImpl.java

@@ -123,6 +123,21 @@ public class CategoryServiceImpl extends AbstractCrudService<Category, Integer>
             if (parentCategory.getChildren() == null) {
                 parentCategory.setChildren(new LinkedList<>());
             }
+
+            StringBuilder fullPath = new StringBuilder();
+
+            if (optionService.isEnabledAbsolutePath()) {
+                fullPath.append(optionService.getBlogBaseUrl());
+            }
+
+            fullPath.append("/")
+                .append(optionService.getCategoriesPrefix())
+                .append("/")
+                .append(child.getSlug())
+                .append(optionService.getPathSuffix());
+
+            child.setFullPath(fullPath.toString());
+
             // Add child
             parentCategory.getChildren().add(child);
         });