<header>

{%- assign default_paths = site.pages | map: "path" -%}
{%- assign page_paths = site.bootstrap.header_pages | default: default_paths -%}
{%- assign titles_size = site.pages | map: 'title' | join: '' | size -%}
<nav class="navbar navbar-expand-lg navbar-light bg-light">
  <div class="container">
    <a class="navbar-brand" href="{{ "/" | relative_url }}">{{ site.title | escape }}</a>
    {%- if titles_size > 0 -%}
    <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarSupportedContent">
      <ul class="navbar-nav ms-auto mb-2 mb-lg-0">
        {%- for path in page_paths -%}
        {%- assign my_page = site.pages | where: "path", path | first -%}
        {%- if my_page.title -%}
        <li class="nav-item">
          <a class="nav-link {% if page.url == my_page.url %} active" aria-current="page{%- endif -%}" href="{{ my_page.url | relative_url }}">{{ my_page.title | escape }}</a>
        </li>
        {%- endif -%}
        {%- endfor -%}
      </ul>
    </div>
    {%- endif -%}
  </div>
</nav>

</header>