{{ $tocLevels := default (default 6 .Site.Params.BookToC) .Params.BookToC }} {{ if and $tocLevels .Page.TableOfContents }} <aside class="book-toc levels-{{$tocLevels}} fixed"> {{ with .Page.TableOfContents }} <label id="toc-control" for="toc-control"> {{ . }} </label> {{ end }} </aside> {{ end }}