change to children/subcat again

_includes/components/children_nav.html

@@ -1,55 +1,23 @@
 {%- comment -%}
-  Include as: {%- include components/children_nav.html -%}
-  Depends on: page, site, nav_breadcrumbs.
-  Results in: HTML for the children-navigation component.
-  Includes: components/nav/sorted.html, toc_heading_custom.html.
-  Overwrites:
-    nav_ancestor_links, nav_top_node_titles, nav_child_candidates, nav_children,
-    nav_child, nav_child_ok, nav_child_ancestor, nav_sorted.
+  Updated to support both `children` and `subcategories` for flexible YAML structures.
 {%- endcomment -%}
-{%- comment -%}
-  Whether a page has any children is checked efficiently by inspecting the cached
-  site_nav. If the page has no children, nav_children is set to an empty array;
-  otherwise nav_children is left unset. (The site_nav is rendered the first time
-  it is included, and that may overwrite various variables.)
-{%- endcomment -%}
-{%- if page.has_children == false -%}
+{%- if page.has_children == false and page.subcategories == nil -%}
   {%- assign nav_children = "" | split: "" -%}
 {%- else -%}
   {%- capture site_nav -%}
-  {%- include_cached components/site_nav.html all=true -%}
-  {%- endcapture -%}
-  {%- assign nav_children = nil -%}
-  {%- capture nav_list_link -%}
-  <a href="{{ page.url | relative_url }}" class="nav-list-link">
+    {%- include_cached components/site_nav.html all=true -%}
   {%- endcapture -%}
-  {%- capture nav_list_simple -%}
-  <ul class="nav-list">
-  {%- endcapture -%}
-  {%- assign nav_child_start = site_nav
-        | split: nav_list_link | last
-        | split: "</a>" | slice: 1 | first -%}
-  {%- assign nav_child_test = nav_child_start
-        | remove_first: nav_list_simple | prepend: nav_list_simple -%}
-  {%- if nav_child_start != nav_child_test -%}
-    {%- assign nav_children = "" | split: "" -%}
-  {%- endif -%}
+  {%- assign nav_children = site_nav | where_exp: "item", "item.parent == page.url" | concat: page.subcategories -%}
 {%- endif -%}
-{%- unless nav_children -%}
-  {%- comment -%}
-    The layout is assumed to include components/breadcrumbs.html before this file,
-    otherwise it needs to be included here.
-  {%- endcomment -%}
+{%- unless nav_children == empty -%}
   {%- assign nav_ancestors = "" | split: "" -%}
   {%- for nav_link in nav_breadcrumbs -%}
     {%- assign nav_title = nav_link | split: ">" | slice: 1 | first | append: ">" | remove: "</a>" -%}
     {%- assign nav_ancestors = nav_ancestors | push: nav_title -%}
   {%- endfor -%}
-  {%- assign nav_parenthood = site[page.collection] | default: site.html_pages
-    | where_exp: "item", "item.title != nil" | group_by: "parent" -%}
-  {%- assign nav_top_nodes = nav_parenthood
-      | where_exp: "item", "item.name == ''" | map: "items" | first -%}
-  {% assign nav_top_node_titles = nav_top_nodes | map: "title" -%}
+  {%- assign nav_parenthood = site[page.collection] | default: site.html_pages | where_exp: "item", "item.title != nil" | group_by: "parent" -%}
+  {%- assign nav_top_nodes = nav_parenthood | where_exp: "item", "item.name == ''" | map: "items" | first -%}
+  {%- assign nav_top_node_titles = nav_top_nodes | map: "title" -%}
   {%- include components/nav/children.html node=page ancestors=nav_ancestors all=true -%}
 {%- endunless -%}
 {%- if nav_children.size >= 1 -%}
@@ -58,11 +26,11 @@
   {%- endif -%}
 <hr>
 {% include toc_heading_custom.html %}
-<ul>
+<ul class="nav-list">
   {% for nav_child in nav_children %}
-  <li>
-    <a href="{{ nav_child.url | relative_url }}">{{ nav_child.title }}</a>{% if nav_child.summary %} - {{ nav_child.summary }}{% endif %}
-  </li>
+    <li>
+      <a href="{{ nav_child.url | relative_url }}">{{ nav_child.title }}</a>
+    </li>
   {% endfor %}
 </ul>
 {%- endif -%}