Excluding page from Jekyll navigation bar

Question

I am setting up a basic Github-hosted Jekyll website (so minimal, I am not even bothering to change the default theme). I have a nested site with a small number of first-tier pages that I would like to appear in the navigation bar (i.e. the default mode of operation). I also have some second-tier pages that I would like to NOT junk up the navigation bar.

While a multi-level navigation system would be nice, I'm trying to avoid using plugins. Therefore, I believe the simplest solution is to just exclude tier two pages from the navigation system entirely.

Here's a hypothetical page structure (minus the other Jekyll files):

jekyllsite
jekyllsite/bar
jekyllsite/bar/alice
jekyllsite/bar/alice/index.md
jekyllsite/bar/bob
jekyllsite/bar/bob/index.md
jekyllsite/bar/index.md
jekyllsite/baz
jekyllsite/baz/index.md
jekyllsite/foo
jekyllsite/foo/eggs
jekyllsite/foo/eggs/index.md
jekyllsite/foo/index.md
jekyllsite/foo/spam
jekyllsite/foo/spam/index.md
jekyllsite/index.md

In descending order of awesome, this is how I'd like this to go down:

1. Best case, context sensitive navigation (don't think possible without plugins): When visiting jekyllsite/index.md, I would get a single layer navigation bar offering me links to foo, bar, and baz. When visiting jekyllsite/bar/index.md, I would see a two-tiered navigation bar containing foo, bar, and baz at the top level, and with alice and bob in the second tier.

2. The next best option would be for me to change something globally, such that only top-level directories (foo, bar, baz) got added to the nav bar. Subdirectories such as alice, bob, spam, and eggs would be automatically excluded from the nav bar.

3. Finally (and I think this might be the easiest) would be for a YAML frontmatter flag to exclude a page. Something like nonav: true in the frontmatter of the page to be excluded.

This seems like it would have to be a fairly common use case, though I haven't been able to find anything that looks like a short path to either of these three options. I'm hoping someone more familiar with Jekyll has a "path of least resistance" answer.

Answer 1

I personally do ;

Front matter for page that appears in main menu

---
layout: default
title: Home
menu: main
weight: 10
---

Main menu template (classes are from twitter bootstrap) :

<ul class="nav navbar-nav">
  {% comment %}Jekyll can now sort on custom page key{% endcomment %}
  {% assign pages = site.pages | sort: 'weight' %} 
  {% for p in pages %}
    {% if p.menu == 'main' %}
      <li{% if p.url == page.url %} class="active"{% endif %}>
         <a href="{{ site.baseurl }}{{ p.url }}">{{ p.title }}</a>
      </li>
    {% endif %}
  {% endfor %}
</ul>

You can then replicate that at any level by setting a custom var in the yaml front matter :

menu : foo

and passing a value to a menu template

{% include navbar.html  menuLevel="foo" %}

And intercept it like this :

{% if p.menu == menuLevel %}

Any page that doesn't expose a menu: toto will not appear in navigation.