Allow span in toc nav items

johnfactotum · johnfactotum · commit 1336e51c402f · 2021-12-16T15:11:55.000+08:00
According to https://www.w3.org/publishing/epub32/epub-packages.html#sec-package-nav-def-model: "A child `a` element describes the target that the link points to, while a `span` element serves as a heading for breaking down lists into distinct groups (for example, a large list of illustrations can be segmented into several lists, one for each chapter)."
diff --git a/src/navigation.js b/src/navigation.js
@@ -191,7 +191,8 @@ class Navigation {
 	 */
 	navItem(item, parent) {
 		let id = item.getAttribute("id") || undefined;
-		let content = filterChildren(item, "a", true);
+		let content = filterChildren(item, "a", true)
+			|| filterChildren(item, "span", true);
 
 		if (!content) {
 			return;
