Content can also be empty

category.go

@@ -16,9 +16,11 @@ type Category struct {
 
 // NewCategory creates a new Category. It returns a *Category and an error.
 func NewCategory(term, content string) (*Category, error) {
+	if content != "" {
 		if !isValidXML(content) {
 			return nil, fmt.Errorf("%v not valid XML", content)
 		}
+	}
 
 	return &Category{Term: term, Content: content}, nil
 }

link.go

@@ -19,9 +19,11 @@ type Link struct {
 
 // NewLink creates a new Link. It returns a *Link and an error.
 func NewLink(href, content string) (*Link, error) {
+	if content != "" {
 		if !isValidXML(content) {
 			return nil, fmt.Errorf("%v not valid XML", content)
 		}
+	}
 
 	return &Link{Href: IRI(href), Content: content}, nil
 }