Merge pull request #7 from ministryofjustice/fix-table-of-contents-li…

…quid-rendering

Use a more robust table of contents renderer

LICENCE

@@ -25,3 +25,9 @@ Ministry of Justice's technical guidance site incorporates code from
 Copyright (c) 2016 Crown Copyright (Government Digital Service).
 GDS's Tech Docs Template is distributed under the terms of the MIT
 License
+
+Ministry of Justice's technical guidance site incorporates [@allejo's
+Pure Liquid Jekyll Table of Contents](https://allejo.io/blog/a-jekyll-toc-in-liquid-only/),
+Copyright (c) 2017 Vladimir Jimenez.
+Pure Liquid Jekyll Table of Contents is distributed under the terms of
+the BSD-3 License

_includes/toc.html

@@ -0,0 +1,62 @@
+{% capture tocWorkspace %}
+    {% comment %}
+        [This code is taken from https://allejo.io/blog/a-jekyll-toc-in-liquid-only/, and used with permissions under the BSD-3 licence]
+
+        "...like all things liquid - where there's a will, and ~36 hours to spare, there's usually a/some way" ~jaybe
+
+        Usage:
+            {% include toc.html html=content sanitize=true class="inline_toc" id="my_toc" h_min=2 h_max=3  %}
+
+        Parameters:
+            * html     (string) - the HTML of compiled markdown generated by kramdown in Jekyll
+
+        Optional Parameters:
+            * sanitize (bool)   : false  - when set to true, the headers will be stripped of any HTML in the TOC
+            * class    (string) :   ''   - a CSS class assigned to the TOC
+            * id       (string) :   ''   - an ID to assigned to the TOC
+            * h_min    (int)    :   1    - the minimum TOC header level to use; any header lower than this value will be ignored
+            * h_max    (int)    :   6    - the maximum TOC header level to use; any header greater than this value will be ignored
+
+        Output:
+            An unordered list representing the table of contents of a markdown block. This snippet will only generate the table of contents and will NOT output the markdown given to it
+    {% endcomment %}
+
+    {% capture my_toc %}{% endcapture %}
+    {% assign minHeader = include.h_min | default: 1 %}
+    {% assign maxHeader = include.h_max | default: 6 %}
+    {% assign nodes = include.html | split: '<h' %}
+    {% for node in nodes %}
+        {% if node == "" %}
+            {% continue %}
+        {% endif %}
+        {% assign headerLevel = node | replace: '"', '' | slice: 0, 1 %}
+        {% assign headerLevel = headerLevel | times: 1 %}
+        {% assign indentAmount = headerLevel | minus: minHeader | add: 1 %}
+        {% assign _workspace = node | split: '</h' %}
+        {% unless headerLevel >= minHeader %}
+            {% continue %}
+        {% endunless %}
+        {% if headerLevel > maxHeader %}
+            {% continue %}
+        {% endif %}
+        {% assign _idWorkspace = _workspace[0] | split: '"' %}
+        {% assign html_id = _idWorkspace[1] %}
+        {% capture _hAttrToStrip %}{{ headerLevel }} id="{{ html_id }}">{% endcapture %}
+        {% assign header = _workspace[0] | replace: _hAttrToStrip, '' %}
+        {% assign space = '' %}
+        {% for i in (1..indentAmount) %}
+            {% assign space = space | prepend: '  ' %}
+        {% endfor %}
+        {% capture my_toc %}{{ my_toc }}
+{{ space }}- [{% if include.sanitize %}{{ header | strip_html }}{% else %}{{ header }}{% endif %}](#{{ html_id }}){% endcapture %}
+    {% endfor %}
+    {% if include.class %}
+        {% capture my_toc %}{:.{{ include.class }}}
+{{ my_toc | lstrip }}{% endcapture %}
+    {% endif %}
+    {% if include.id %}
+        {% capture my_toc %}{: #{{ include.id }}}
+{{ my_toc | lstrip }}{% endcapture %}
+    {% endif %}
+{% endcapture %}{% assign tocWorkspace = '' %}
+{{ my_toc | markdownify }}

_layouts/default.html

@@ -43,14 +43,7 @@
           <div class="toc" data-module="table-of-contents">
             <a href="#" class="toc__close js-toc-close" aria-controls="toc" aria-label="Hide table of contents"></a>
             <nav id="toc" class="js-toc-list toc__list" aria-labelledby="toc-heading">
-              {% capture toc_markdown %}
-{{ page.content }}
-<!-- TOC-start-marker -->
-* auto-gen TOC:
-{:toc}
-              {% endcapture %}
-              {% assign rendered_markdown_with_toc = toc_markdown | markdownify | split: '<!-- TOC-start-marker -->' %}
-              {{ rendered_markdown_with_toc[1] }}
+              {% include toc.html html=content %}
             </nav>
           </div>
         </div>

index.md

@@ -16,10 +16,8 @@ which covers service design more broadly.
 {% for standard_group in standards %}
 {% if standard_group.name != "" %}
 ### {{ standard_group.name }}
-{:.no_toc}
 {% else %}
 ### General standards
-{:.no_toc}
 {% endif %}
 
 {% for standard in standard_group.items %}