feat(analytics)!: add post pageviews for GoatCounter (cotes2020#1543)

---------

Co-authored-by: Cotes Chung <[email protected]>

_config.yml

@@ -49,11 +49,16 @@ google_site_verification: # fill in to your verification string
 # ↑ --------------------------
 # The end of `jekyll-seo-tag` settings
 
-google_analytics:
-  id: # fill in your Google Analytics ID
-
-goatcounter:
-  id: # fill in your Goatcounter ID
+# Web Analytics Settings
+analytics:
+  google:
+    id: # fill in your Google Analytics ID
+  goatcounter:
+    id: # fill in your GoatCounter ID
+
+# Pageviews settings
+pageviews:
+  provider: # now only supports 'goatcounter'
 
 # Prefer color scheme setting.
 #

_includes/analytics/goatcounter.html

@@ -0,0 +1,6 @@
+<!-- GoatCounter -->
+<script
+  async
+  src="//gc.zgo.at/count.js"
+  data-goatcounter="https://{{ site.analytics.goatcounter.id }}.goatcounter.com/count"
+></script>

_includes/analytics/google.html

@@ -0,0 +1,13 @@
+<!-- Global site tag (gtag.js) - Google Analytics -->
+<script defer src="https://www.googletagmanager.com/gtag/js?id={{ site.analytics.google.id }}"></script>
+<script>
+  document.addEventListener('DOMContentLoaded', function (event) {
+    window.dataLayer = window.dataLayer || [];
+    function gtag() {
+      dataLayer.push(arguments);
+    }
+
+    gtag('js', new Date());
+    gtag('config', '{{ site.analytics.google.id }}');
+  });
+</script>

_includes/head.html

@@ -72,7 +72,7 @@
   {% endif %}
 
   <!-- GA -->
-  {% if jekyll.environment == 'production' and site.google_analytics.id != empty and site.google_analytics.id %}
+  {% if jekyll.environment == 'production' and site.analytics.google.id != empty and site.analytics.google.id %}
     <link rel="preconnect" href="https://www.google-analytics.com" crossorigin="use-credentials">
     <link rel="dns-prefetch" href="https://www.google-analytics.com">
 

_includes/js-selector.html

@@ -95,19 +95,32 @@
   <script id="MathJax-script" async src="{{ site.data.origin[type].mathjax.js | relative_url }}"></script>
 {% endif %}
 
+<!-- Pageviews -->
+{% if page.layout == 'post' %}
+  {% assign provider = site.pageviews.provider %}
+
+  {% if provider and provider != empty %}
+    {% case provider %}
+      {% when 'goatcounter' %}
+        {% if site.analytics[provider].id != empty and site.analytics[provider].id %}
+          {% include pageviews/{{ provider }}.html %}
+        {% endif %}
+    {% endcase %}
+  {% endif %}
+{% endif %}
+
 {% if jekyll.environment == 'production' %}
   <!-- PWA -->
   {% if site.pwa.enabled %}
     <script defer src="{{ 'app.min.js' | prepend: js_dist | relative_url }}"></script>
   {% endif %}
 
-  <!-- GA -->
-  {% if site.google_analytics.id != empty and site.google_analytics.id %}
-    {% include google-analytics.html %}
-  {% endif %}
-
-  <!-- GoatCounter -->
-  {% if site.goatcounter.id != empty and site.goatcounter.id %}
-    {% include goatcounter.html %}
-  {% endif %}
+  <!-- Web Analytics -->
+  {% for analytics in site.analytics %}
+    {% capture str %}{{ analytics }}{% endcapture %}
+    {% assign type = str | split: '{' | first %}
+    {% if site.analytics[type].id and site.analytics[type].id != empty %}
+      {% include analytics/{{ type }}.html %}
+    {% endif %}
+  {% endfor %}
 {% endif %}

_includes/pageviews/goatcounter.html

@@ -0,0 +1,18 @@
+<!-- Display GoatCounter pageviews -->
+<script>
+  let pv = document.getElementById('pageviews');
+
+  if (pv !== null) {
+    const uri = location.pathname.replace(/\/$/, '');
+    const url = `https://{{ site.analytics.goatcounter.id }}.goatcounter.com/counter/${encodeURIComponent(uri)}.json`;
+
+    fetch(url)
+      .then((response) => response.json())
+      .then((data) => {
+        pv.innerText = new Intl.NumberFormat().format(data.count);
+      })
+      .catch((error) => {
+        pv.innerText = '1';
+      });
+  }
+</script>

_layouts/post.html

@@ -74,12 +74,22 @@ <h1 data-toc-skip>{{ page.title }}</h1>
           </em>
         </span>
 
-        <!-- read time -->
-        {% include read-time.html content=content prompt=true lang=lang %}
+        <div>
+          <!-- pageviews -->
+          {% if site.pageviews.provider and site.analytics[site.pageviews.provider].id %}
+            <span>
+              <em id="pageviews">
+                <i class="fas fa-spinner fa-spin small"></i>
+              </em>
+              {{ site.data.locales[lang].post.pageview_measure }}
+            </span>
+          {% endif %}
+
+          <!-- read time -->
+          {% include read-time.html content=content prompt=true lang=lang %}
+        </div>
       </div>
-      <!-- .d-flex -->
     </div>
-    <!-- .post-meta -->
   </header>
 
   <div class="content">

_sass/layout/post.scss

@@ -15,7 +15,7 @@
 }
 
 h1 + .post-meta {
-  > span + span::before {
+  span + span::before {
     @include dot;
   }