   {%- comment -%} Yet-another hacky way to do things with Liquid This
   include constructs breadcrumbs for the page; breadcrumbs are based on the
   page's location in the TOC (_data/toc.yaml). To get the "parent" TOC
   entries for the current page, we: - iterate through each of the main
   sections / categories in the TOC (home, guides, manuals, reference,
   samples) - in each section, we iterate throught pages and sections.
   "sections" do not have URLs ("path") of their own, but can contain pages
   and sub-sections. Liquid doesn't allow us to "recursively" iterate through
   these, so we added code for each nested level (currently accounting for
   pages to be nested up to 4 levels deep) - If the item we're checking is a
   page (i.e., has a "path" property), and the "path" matches the current
   page, then we found our "breadcrumb path"; in this case we store the
   parent elements into variables (levelX_title, levelX_url). Liquid doesn't
   seem to like storing the whole struct into a variable (we can *store* it
   in a variable, but the "path" property ends up empty). We also have to
   "assign" inside the level-block; likely because variables assigned in the
   previous block gets out of scope. - Because (as mentioned) "sections"
   themselves currently do not have their own URL, we don't have a real
   "parent" URL, so we're using the _first_ page at each level as the
   "closest match". In some cases, a section does not contain pages (only
   subsections); in those cases, our breadcrumbs will contain "titles" for
   parent locations, but no link. (This is something we need to fix: make
   sure that each section has a landing-page, and possibly add a "path" field
   to sections (containing the landing page of the section). {%- endcomment
   -%} {%- for section in site.data.toc.horizontalnav -%} {%- for level1 in
   site.data.toc[section.node] -%} {%- if level1.path == page.url -%} {%-
   assign found = "true" -%} {%- assign section_title = section.title -%} {%-
   assign section_url = section.path -%} {%- assign level1_title =
   level1.title -%} {%- assign level1_url = level1.path -%} {%- break -%} {%-
   endif -%} {%- for level2 in level1.section -%} {%- if level2.path ==
   page.url -%} {%- assign found = "true" -%} {%- assign section_title =
   section.title -%} {%- assign section_url = section.path -%} {%- assign
   level1_title = level1.sectiontitle -%} {%- assign level1_url =
   level1.section[0].path -%} {%- assign level2_title = level2.title -%} {%-
   assign level2_url = level2.path -%} {%- break -%} {%- endif -%} {%- for
   level3 in level2.section -%} {%- if level3.path == page.url -%} {%- assign
   found = "true" -%} {%- assign section_title = section.title -%} {%- assign
   section_url = section.path -%} {%- assign level1_title =
   level1.sectiontitle -%} {%- assign level1_url = level1.section[0].path -%}
   {%- assign level2_title = level2.sectiontitle -%} {%- assign level2_url =
   level2.section[0].path -%} {%- assign level3_title = level3.title -%} {%-
   assign level3_url = level3.path -%} {%- break -%} {%- endif -%} {%- for
   level4 in level3.section -%} {%- if level4.path == page.url -%} {%- assign
   found = "true" -%} {%- assign section_title = section.title -%} {%- assign
   section_url = section.path -%} {%- assign level1_title =
   level1.sectiontitle -%} {%- assign level1_url = level1.section[0].path -%}
   {%- assign level2_title = level2.sectiontitle -%} {%- assign level2_url =
   level2.section[0].path -%} {%- assign level3_title = level3.sectiontitle
   -%} {%- assign level3_url = level3.section[0].path -%} {%- assign
   level4_title = level4.title -%} {%- assign level4_url = level4.path -%}
   {%- break -%} {%- endif -%} {%- endfor -%} {%- endfor -%} {%- endfor -%}
   {%- endfor -%} {%- comment -%} Some section's overview page are not in the
   TOC. If we didn't find a matching page in the TOC so far, use the section
   itself for the breadcrumb. {%- endcomment -%} {%- if section.path ==
   page.url -%} {%- assign found = "true" -%} {%- assign section_title =
   section.title -%} {%- assign section_url = section.path -%} {%- break -%}
   {%- endif -%} {%- endfor -%} {%- if found == "true" -%}
    1.  2. {{ section_title }} {%- if level1_title -%}
    3. {{ level1_title }}{%- endif -%} {%- if level2_title -%}
    4. {{ level2_title }}{%- endif -%} {%- if level3_title -%}
    5. {{ level3_title }}{%- endif -%} {%- if level4_title -%}
    6. {{ level4_title }}{%- endif -%}
   {%- endif -%}
