cherrykitten.dev/templates/macros/menu.html

{% macro menu(config, current_path) %}
    {%- set current_item = false -%}
    {%- if config.extra.menu_items %}
        {%- set menu_items = config.extra.menu_items -%}

            {%- for item in menu_items %}
                {%- set abs_item_url = item.url | replace(from="$BASE_URL", to=config.base_url) -%}
                {%- set is_current = current_url == abs_item_url ~ "/"
                                     or current_url is starting_with(abs_item_url)
                -%}
                {%- set is_base = abs_item_url == config.base_url
                                  or abs_item_url == config.base_url ~ "/"
                -%}

                {%- if is_base %}
                    {%- set_global base_item = item -%}
                {% endif -%}

                {%- if is_current and not is_base %}
                    {%- set_global current_item = item -%}
                {% endif -%}
            {% endfor -%}

            {%- if not current_item and base_item %}
                {# Did not match any menu URLs -- assume it's a blog post #}
                {%- set current_item = base_item -%}
            {% endif -%}

            {{ menu_macros::menu_for(config=config, current_item=current_item) }}
    {% endif -%}
{% endmacro menu %}

{% macro menu_for(config, current_item) %}
    {%- if config.extra.menu_items %}
        {%- set menu_items = config.extra.menu_items -%}

        <nav class="menu noprint">
            <ul class="menu__inner">
            {%- for item in menu_items %}
                <li {%- if current_item and current_item == item %} class="active" {%- endif %}>
                    {%- if item.newtab -%}
                        <a href="{{ item.url | replace(from="$BASE_URL", to=config.base_url) | safe }}" target="_blank" rel="noopener noreferrer">{{ item.name | safe }}</a>
                    {%- else -%}
                        <a href="{{ item.url | replace(from="$BASE_URL", to=config.base_url) | safe }}">{{ item.name | safe }}</a>
                    {%- endif -%}
                </li>
            {% endfor -%}
            </ul>
        </nav>
    {% endif -%}
{% endmacro menu %}