From 10bc44367a15dfa96fc34375643e7d6b33de4d2f Mon Sep 17 00:00:00 2001
From: Cotes Chung <11371340+cotes2020@users.noreply.github.com>
Date: Thu, 19 Nov 2020 01:58:35 +0800
Subject: [PATCH] Add hook to generate the lastmod of posts

---
 _includes/panel.html           | 30 +++++++++++-------------------
 _includes/update-list.html     | 12 +++++++-----
 _layouts/post.html             | 17 ++---------------
 _plugins/posts-lastmod-hook.rb | 11 +++++++++++
 feed.xml                       |  8 ++++----
 sitemap.xml                    | 22 ++++++++--------------
 6 files changed, 43 insertions(+), 57 deletions(-)
 create mode 100644 _plugins/posts-lastmod-hook.rb

diff --git a/_includes/panel.html b/_includes/panel.html
index 35997c2..190c1f6 100644
--- a/_includes/panel.html
+++ b/_includes/panel.html
@@ -10,33 +10,25 @@
 
   <div class="access">
 
-  {% if site.data.updates %}
-
-    {% include update-list.html %}
-
-    {% if update_list.size > 0 %}
-
+  {% include update-list.html %}
+  
+  {% if update_list.size > 0 %}
+    
     <div id="access-lastmod" class="post">
       <span>{{- site.data.label.panel.lastmod -}}</span>
       <ul class="post-content pl-0 pb-1 ml-1 mt-2">
 
       {% for item in update_list %}
-        {% assign post_url = item | split: "::" | last | url_encode | prepend: "/posts/" | append: "/" %}
-        {% assign post = site.posts | where: "url", post_url | first %}
-
-        {% if post %}
-          {% assign url = post.url | relative_url %}
-          <li><a href="{{ url }}">{{ post.title }}</a></li>
-        {% endif %}
-
+        {% assign index = item | split: "::" | last | plus: 0 %}
+        {% assign post = site.posts[index] %}
+        {% assign url = post.url | relative_url %}
+        <li><a href="{{ url }}">{{ post.title }}</a></li>
       {% endfor %}
 
       </ul>
-    </div><!-- #access-lastmod -->
-
-    {% endif %}
-
-  {% endif %} <!-- site.data.updates -->
+    </div> <!-- #access-lastmod -->
+  
+  {% endif %}
 
   {% include trending-tags.html %}
 
diff --git a/_includes/update-list.html b/_includes/update-list.html
index 231d9a0..b0eb52a 100644
--- a/_includes/update-list.html
+++ b/_includes/update-list.html
@@ -10,11 +10,13 @@
 
 {% assign all_list = "" | split: "" %}
 
-{% for entry in site.data.updates %}
-  {% capture elem %}
-    {{- entry.lastmod -}}::{{- entry.filename -}}
-  {% endcapture %}
-  {% assign all_list = all_list | push: elem %}
+{% for post in site.posts %}
+  {% if post.lastmod %}
+    {% capture elem %}
+      {{- post.lastmod | date: "%Y%m%d%H%M%S" -}}::{{- forloop.index0 -}}
+    {% endcapture %}
+    {% assign all_list = all_list | push: elem %}
+  {% endif %}
 {% endfor %}
 
 {% assign all_list = all_list | sort | reverse %}
diff --git a/_layouts/post.html b/_layouts/post.html
index 94ea43a..cee27cc 100644
--- a/_layouts/post.html
+++ b/_layouts/post.html
@@ -31,22 +31,10 @@ layout: default
         </div>
 
         <!-- lastmod -->
-        {%- capture filename -%}
-          {{ page.url | split: "/" | last }}
-        {%- endcapture -%}
-
-        {% for item in site.data.updates %}
-          {% assign encode_filename = item.filename | url_encode %}
-          {% if filename == encode_filename %}
-            {% assign lastmod = item.lastmod %}
-            {% break %}
-          {% endif %}
-        {% endfor %}
-
-        {% if lastmod %}
+        {% if page.lastmod %}
         <div>
           Updated
-          {% include timeago.html date=lastmod class="lastmod" tooltip=true %}
+          {% include timeago.html date=page.lastmod class="lastmod" tooltip=true %}
         </div>
         {% endif %}
 
@@ -61,7 +49,6 @@ layout: default
       </div> <!-- .post-meta -->
 
       <div class="post-content">
-
         {%- capture img_placehodler -%}
           data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7
         {% endcapture%}
diff --git a/_plugins/posts-lastmod-hook.rb b/_plugins/posts-lastmod-hook.rb
new file mode 100644
index 0000000..5119b48
--- /dev/null
+++ b/_plugins/posts-lastmod-hook.rb
@@ -0,0 +1,11 @@
+# Check for changed posts
+Jekyll::Hooks.register :posts, :post_init do |post|
+
+  commit_num = `git rev-list --count HEAD "#{ post.path }"`
+
+  if commit_num.to_i > 1
+    lastmod_date = `git log -1 --pretty="%ad" --date=iso "#{ post.path }"`
+    post.data['lastmod'] = lastmod_date
+  end
+
+end
diff --git a/feed.xml b/feed.xml
index 30e01fc..0d88b56 100644
--- a/feed.xml
+++ b/feed.xml
@@ -30,10 +30,10 @@ layout: compress
     <title>{{ post.title }}</title>
     <link href="{{ post_absolute_url }}" rel="alternate" type="text/html" title="{{ post.title }}" />
     <published>{{ post.date | date_to_xmlschema }}</published>
-  {% if post.seo.date_modified %}
-    <updated>{{ post.seo.date_modified | date_to_xmlschema }}</updated>
+  {% if post.lastmod %}
+    <updated>{{ post.lastmod | date_to_xmlschema }}</updated>
   {% else %}
-    <updated>{{ site.time | date_to_xmlschema }}</updated>
+    <updated>{{ post.date | date_to_xmlschema }}</updated>
   {% endif %}
     <id>{{ post_absolute_url }}</id>
     <content src="{{ post_absolute_url }}" />
@@ -60,4 +60,4 @@ layout: compress
 {% endfor %}
 </feed>
 {% endcapture %}
-{{ source | replace: '&', '&amp;' }}
\ No newline at end of file
+{{ source | replace: '&', '&amp;' }}
diff --git a/sitemap.xml b/sitemap.xml
index 7b0bb70..1fb01fa 100644
--- a/sitemap.xml
+++ b/sitemap.xml
@@ -14,7 +14,11 @@ layout: compress
 {% for post in site.posts %}
   <url>
     <loc>{{ site.url | append: site.baseurl | append: post.url }}</loc>
-    <lastmod>{{ site.time | date_to_xmlschema }}</lastmod>
+    {% if post.lastmod %}
+      <lastmod>{{ post.lastmod | date_to_xmlschema }}</lastmod>
+    {% else %}
+      <lastmod>{{ post.date | date_to_xmlschema }}</lastmod>
+    {% endif %}
 
     {% if post.sitemap.changefreq %}
       <changefreq>{{ post.sitemap.changefreq }}</changefreq>
@@ -59,19 +63,9 @@ layout: compress
     {% continue %}
   {% endif %}
 
-  {% capture lastmod %}
-    {% if page.lastmod %}
-      {{ page.lastmod }}
-    {% elsif page.date %}
-      {{ page.date }}
-    {% else %}
-      {{ site.time }}
-    {% endif %}
-  {% endcapture %}
-
-   <url>
+  <url>
     <loc>{{ site.url | append: site.baseurl | append: page.url | remove: "index.html" }}</loc>
-    <lastmod>{{ lastmod | date_to_xmlschema }}</lastmod>
+    <lastmod>{{ site.time | date_to_xmlschema }}</lastmod>
 
     {% if page.sitemap.changefreq %}
       <changefreq>{{ page.sitemap.changefreq }}</changefreq>
@@ -88,4 +82,4 @@ layout: compress
 
 {% endfor %}
 
-</urlset>
\ No newline at end of file
+</urlset>