From 23bf432514c67ac7714cb51846f4ffc8353afd41 Mon Sep 17 00:00:00 2001
From: Fabien O'Carroll <fabien@allou.is>
Date: Tue, 14 Jul 2020 11:14:10 +0200
Subject: [PATCH] Updated AMP output to include Google Analytics

refs #11980

This adds a new handlebars helper {{amp_analytics}} which outputs the
GA configuration script if the amp_gtag_id setting is present.

We also update {{amp_components}} to output the GA script in the head if
the setting is present
---
 .../apps/amp/lib/helpers/amp_analytics.js     | 35 +++++++++++++++++++
 .../apps/amp/lib/helpers/amp_components.js    |  4 +++
 core/frontend/apps/amp/lib/helpers/index.js   |  2 ++
 core/frontend/apps/amp/lib/views/amp.hbs      |  1 +
 4 files changed, 42 insertions(+)
 create mode 100644 core/frontend/apps/amp/lib/helpers/amp_analytics.js

diff --git a/core/frontend/apps/amp/lib/helpers/amp_analytics.js b/core/frontend/apps/amp/lib/helpers/amp_analytics.js
new file mode 100644
index 0000000000..cc757104ad
--- /dev/null
+++ b/core/frontend/apps/amp/lib/helpers/amp_analytics.js
@@ -0,0 +1,35 @@
+// # Amp Components Helper
+// Usage: `{{amp_analytics}}`
+//
+// Outputs inline scripts used for analytics
+
+const proxy = require('../../../../services/proxy');
+
+const SafeString = proxy.SafeString;
+const settingsCache = proxy.settingsCache;
+
+function ampComponents() {
+    let components = [];
+
+    const ampGtagId = settingsCache.get('amp_gtag_id');
+    if (ampGtagId) {
+        components.push(`
+            <amp-analytics type="gtag" data-credentials="include">
+                <script type="application/json">
+                    {
+                        "vars" : {
+                            "gtag_id": "${ampGtagId}",
+                            "config" : {
+                                "${ampGtagId}": { "groups": "default" }
+                            }
+                        }
+                    }
+                </script>
+            </amp-analytics>
+        `);
+    }
+
+    return new SafeString(components.join('\n'));
+}
+
+module.exports = ampComponents;
diff --git a/core/frontend/apps/amp/lib/helpers/amp_components.js b/core/frontend/apps/amp/lib/helpers/amp_components.js
index 149f6f140f..017c68f0a1 100644
--- a/core/frontend/apps/amp/lib/helpers/amp_components.js
+++ b/core/frontend/apps/amp/lib/helpers/amp_components.js
@@ -39,6 +39,10 @@ function ampComponents() {
         components.push('<script async custom-element="amp-audio" src="https://cdn.ampproject.org/v0/amp-audio-0.1.js"></script>');
     }
 
+    if (proxy.settingsCache.get('amp_gtag_id')) {
+        components.push('<script async custom-element="amp-analytics" src="https://cdn.ampproject.org/v0/amp-analytics-0.1.js"></script>');
+    }
+
     return new SafeString(components.join('\n'));
 }
 
diff --git a/core/frontend/apps/amp/lib/helpers/index.js b/core/frontend/apps/amp/lib/helpers/index.js
index da7567c5a1..940c8e1bde 100644
--- a/core/frontend/apps/amp/lib/helpers/index.js
+++ b/core/frontend/apps/amp/lib/helpers/index.js
@@ -6,6 +6,8 @@ function registerAmpHelpers(ghost) {
 
     ghost.helpers.register('amp_components', require('./amp_components'));
 
+    ghost.helpers.register('amp_analytics', require('./amp_analytics'));
+
     // we use the {{ghost_head}} helper, but call it {{amp_ghost_head}}, so it's consistent
     ghost.helpers.registerAsync('amp_ghost_head', ghostHead);
 }
diff --git a/core/frontend/apps/amp/lib/views/amp.hbs b/core/frontend/apps/amp/lib/views/amp.hbs
index 14dd1af297..597453ec13 100644
--- a/core/frontend/apps/amp/lib/views/amp.hbs
+++ b/core/frontend/apps/amp/lib/views/amp.hbs
@@ -622,5 +622,6 @@
         <p><a href="{{@site.url}}">Read more posts →</a></p>
         <a class="powered" href="https://ghost.org" target="_blank" rel="noopener"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 156 156"><g fill="none" fill-rule="evenodd"><rect fill="#15212B" width="156" height="156" rx="27"/><g transform="translate(36 36)" fill="#F6F8FA"><path d="M0 71.007A4.004 4.004 0 014 67h26a4 4 0 014 4.007v8.986A4.004 4.004 0 0130 84H4a4 4 0 01-4-4.007v-8.986zM50 71.007A4.004 4.004 0 0154 67h26a4 4 0 014 4.007v8.986A4.004 4.004 0 0180 84H54a4 4 0 01-4-4.007v-8.986z"/><rect y="34" width="84" height="17" rx="4"/><path d="M0 4.007A4.007 4.007 0 014.007 0h41.986A4.003 4.003 0 0150 4.007v8.986A4.007 4.007 0 0145.993 17H4.007A4.003 4.003 0 010 12.993V4.007z"/><rect x="67" width="17" height="17" rx="4"/></g></g></svg> Published with Ghost</a></span>
     </footer>
+    {{amp_analytics}}
 </body>
 </html>
\ No newline at end of file