Support generate TOC for posts.

Resolves #4, resolves #5.

README.md

@@ -27,6 +27,17 @@ This theme can be used just as other [Jekyll themes][1].
 
 [Fork][3] this repository and add your markdown posts to the `_posts` folder.
 
+## How to generate TOC
+
+The jekyll-gitbook theme leverages [jekyll-toc][4] to generate the *Contents* for the page.
+The TOC feature is not enabled by default. To use the TOC feature, modify the TOC
+configuration in `_config.yml`:
+
+```yaml
+toc:
+    enabled: true
+```
+
 ## License
 
 This work is open sourced under the Apache License, Version 2.0.
@@ -36,3 +47,4 @@ Copyright 2019 Tao He.
 [1]: https://pages.github.com
 [2]: https://pages.github.com/themes
 [3]: https://github.com/sighingnow/jekyll-gitbook/fork
+[4]: https://github.com/allejo/jekyll-toc

_config.yml

@@ -13,6 +13,11 @@ url:              'https://sighingnow.github.io'
 baseurl:          '/jekyll-gitbook'
 rss:              RSS
 
+toc:
+  enabled: true
+  h_min: 1
+  h_max: 3
+
 # markdown render engine.
 markdown:         kramdown
 kramdown:

_includes/toc-date.html

@@ -27,6 +27,11 @@
                     <a href="{{site.baseurl}}{{post.url}}">
                         {{ post.title | escape }}
                     </a>
+                    {% if site.toc.enabled %}
+                        {% if page.url == post.url %}
+                            {% include toc.html html=content h_min=site.toc.h_min h_max=site.toc.h_max %}
+                        {% endif %}
+                    {% endif %}
                 </li>
             {% endfor %}
 

_includes/toc.html

@@ -0,0 +1,182 @@
+{% capture tocWorkspace %}
+    {% comment %}
+        Copyright (c) 2017 Vladimir "allejo" Jimenez
+
+        Permission is hereby granted, free of charge, to any person
+        obtaining a copy of this software and associated documentation
+        files (the "Software"), to deal in the Software without
+        restriction, including without limitation the rights to use,
+        copy, modify, merge, publish, distribute, sublicense, and/or sell
+        copies of the Software, and to permit persons to whom the
+        Software is furnished to do so, subject to the following
+        conditions:
+
+        The above copyright notice and this permission notice shall be
+        included in all copies or substantial portions of the Software.
+
+        THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+        EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+        OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+        NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+        HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+        WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+        FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+        OTHER DEALINGS IN THE SOFTWARE.
+    {% endcomment %}
+    {% comment %}
+        Version 1.1.0
+          https://github.com/allejo/jekyll-toc
+
+        "...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
+            * ordered       (bool)   : false  - when set to true, an ordered list will be outputted instead of an unordered list
+            * item_class    (string) :   ''   - add custom class(es) for each list item; has support for '%level%' placeholder, which is the current heading level
+            * submenu_class (string) :   ''   - add custom class(es) for each child group of headings; has support for '%level%' placeholder which is the current "submenu" heading level
+            * base_url      (string) :   ''   - add a base url to the TOC links for when your TOC is on another page than the actual content
+            * anchor_class  (string) :   ''   - add custom class(es) for each anchor element
+            * skip_no_ids   (bool)   : false  - skip headers that do not have an `id` attribute
+
+        Output:
+            An ordered or 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 newline %}
+    {% endcapture %}
+    {% assign newline = newline | rstrip %} <!-- Remove the extra spacing but preserve the newline -->
+
+    {% capture deprecation_warnings %}{% endcapture %}
+
+    {% if include.baseurl %}
+        {% capture deprecation_warnings %}{{ deprecation_warnings }}<!-- jekyll-toc :: "baseurl" has been deprecated, use "base_url" instead -->{{ newline }}{% endcapture %}
+    {% endif %}
+
+    {% if include.skipNoIDs %}
+        {% capture deprecation_warnings %}{{ deprecation_warnings }}<!-- jekyll-toc :: "skipNoIDs" has been deprecated, use "skip_no_ids" instead -->{{ newline }}{% endcapture %}
+    {% endif %}
+
+    {% capture jekyll_toc %}{% endcapture %}
+    {% assign orderedList = include.ordered | default: false %}
+    {% assign baseURL = include.base_url | default: include.baseurl | default: '' %}
+    {% assign skipNoIDs = include.skip_no_ids | default: include.skipNoIDs | default: false %}
+    {% assign minHeader = include.h_min | default: 1 %}
+    {% assign maxHeader = include.h_max | default: 6 %}
+    {% assign nodes = include.html | strip | split: '<h' %}
+
+    {% assign firstHeader = true %}
+    {% assign currLevel = 0 %}
+    {% assign lastLevel = 0 %}
+
+    {% capture listModifier %}{% if orderedList %}ol{% else %}ul{% endif %}{% endcapture %}
+
+    {% for node in nodes %}
+        {% if node == "" %}
+            {% continue %}
+        {% endif %}
+
+        {% assign currLevel = node | replace: '"', '' | slice: 0, 1 | times: 1 %}
+
+        {% if currLevel < minHeader or currLevel > maxHeader %}
+            {% continue %}
+        {% endif %}
+
+        {% assign _workspace = node | split: '</h' %}
+
+        {% assign _idWorkspace = _workspace[0] | split: 'id="' %}
+        {% assign _idWorkspace = _idWorkspace[1] | split: '"' %}
+        {% assign htmlID = _idWorkspace[0] %}
+
+        {% assign _classWorkspace = _workspace[0] | split: 'class="' %}
+        {% assign _classWorkspace = _classWorkspace[1] | split: '"' %}
+        {% assign htmlClass = _classWorkspace[0] %}
+
+        {% if htmlClass contains "no_toc" %}
+            {% continue %}
+        {% endif %}
+
+        {% if firstHeader %}
+            {% assign minHeader = currLevel %}
+        {% endif %}
+
+        {% capture _hAttrToStrip %}{{ _workspace[0] | split: '>' | first }}>{% endcapture %}
+        {% assign header = _workspace[0] | replace: _hAttrToStrip, '' %}
+
+        {% if include.item_class and include.item_class != blank %}
+            {% capture listItemClass %} class="{{ include.item_class | replace: '%level%', currLevel | split: '.' | join: ' ' }}"{% endcapture %}
+        {% endif %}
+
+        {% if include.submenu_class and include.submenu_class != blank %}
+            {% assign subMenuLevel = currLevel | minus: 1 %}
+            {% capture subMenuClass %} class="{{ include.submenu_class | replace: '%level%', subMenuLevel | split: '.' | join: ' ' }}"{% endcapture %}
+        {% endif %}
+
+        {% capture anchorBody %}{% if include.sanitize %}{{ header | strip_html }}{% else %}{{ header }}{% endif %}{% endcapture %}
+
+        {% if htmlID %}
+            {% capture anchorAttributes %} href="{% if baseURL %}{{ baseURL }}{% endif %}#{{ htmlID }}"{% endcapture %}
+
+            {% if include.anchor_class %}
+                {% capture anchorAttributes %}{{ anchorAttributes }} class="{{ include.anchor_class | split: '.' | join: ' ' }}"{% endcapture %}
+            {% endif %}
+
+            {% capture listItem %}<a{{ anchorAttributes }}>{{ anchorBody }}</a>{% endcapture %}
+        {% elsif skipNoIDs == true %}
+            {% continue %}
+        {% else %}
+            {% capture listItem %}{{ anchorBody }}{% endcapture %}
+        {% endif %}
+
+        {% if currLevel > lastLevel %}
+            {% capture jekyll_toc %}{{ jekyll_toc }}<{{ listModifier }}{{ subMenuClass }}>{% endcapture %}
+        {% elsif currLevel < lastLevel %}
+            {% assign repeatCount = lastLevel | minus: currLevel %}
+
+            {% for i in (1..repeatCount) %}
+                {% capture jekyll_toc %}{{ jekyll_toc }}</li></{{ listModifier }}>{% endcapture %}
+            {% endfor %}
+
+            {% capture jekyll_toc %}{{ jekyll_toc }}</li>{% endcapture %}
+        {% else %}
+            {% capture jekyll_toc %}{{ jekyll_toc }}</li>{% endcapture %}
+        {% endif %}
+
+        {% capture jekyll_toc %}{{ jekyll_toc }}<li{{ listItemClass }}>{{ listItem }}{% endcapture %}
+
+        {% assign lastLevel = currLevel %}
+        {% assign firstHeader = false %}
+    {% endfor %}
+
+    {% assign repeatCount = minHeader | minus: 1 %}
+    {% assign repeatCount = lastLevel | minus: repeatCount %}
+    {% for i in (1..repeatCount) %}
+        {% capture jekyll_toc %}{{ jekyll_toc }}</li></{{ listModifier }}>{% endcapture %}
+    {% endfor %}
+
+    {% if jekyll_toc != '' %}
+        {% assign rootAttributes = '' %}
+        {% if include.class and include.class != blank %}
+            {% capture rootAttributes %} class="{{ include.class | split: '.' | join: ' ' }}"{% endcapture %}
+        {% endif %}
+
+        {% if include.id and include.id != blank %}
+            {% capture rootAttributes %}{{ rootAttributes }} id="{{ include.id }}"{% endcapture %}
+        {% endif %}
+
+        {% if rootAttributes %}
+            {% assign nodes = jekyll_toc | split: '>' %}
+            {% capture jekyll_toc %}<{{ listModifier }}{{ rootAttributes }}>{{ nodes | shift | join: '>' }}>{% endcapture %}
+        {% endif %}
+    {% endif %}
+{% endcapture %}{% assign tocWorkspace = '' %}{{ deprecation_warnings }}{{ jekyll_toc }}

_posts/2019-04-28-howto.md

@@ -6,7 +6,7 @@ category: Jekyll
 layout: post
 ---
 
-This theme can be used just as other [Jekyll themes][1].
+The jekyll-gitbook theme can be used just as other [Jekyll themes][1].
 
 [Fork][2] this repository and add your markdown posts to the `_posts` folder, then
 push to your own Github repository. No need to push generated HTML bundle.

_posts/2019-04-29-license.md

@@ -1,7 +1,7 @@
 ---
 title: License
 author: Tao He
-date: 2019-04-28
+date: 2019-04-29
 category: Jekyll
 layout: post
 ---