From bf718531685353dd7c53a8966118ecb8f6d7e845 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Frank=20Bo=C3=ABs?= <fboes@3960.org>
Date: Thu, 30 Aug 2018 18:52:19 +0200
Subject: [PATCH] Add Handlebar helpers to export Google Tag Manager Datalayer
 &  Add Handlebar helpers for data dumping

---
 CHANGELOG.md                                |  2 ++
 docs/development.md                         |  4 ++-
 lib/helpers/blogophon-handlebars-quoters.js | 27 +++++++++++++++++++++
 3 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 894d15c5..1a5a1693 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -23,6 +23,8 @@ For detailed information check [Blogophon's releases on Github](https://github.c
 * :gift: Add [abc music notation](http://abcnotation.com/wiki/abc:standard:v2.1) syntax highlighter
 * :gift: Add [Exapunks' AXIOM](http://www.zachtronics.com/exapunks/) syntax highlighter
 * :gift: Add more information to `opensearch.xml`
+* :gift: Add Handlebar helpers to export Google Tag Manager Datalayer
+* :gift: Add Handlebar helpers for data dumping
 
 1.5.0
 -----
diff --git a/docs/development.md b/docs/development.md
index fd266e20..001d3d63 100644
--- a/docs/development.md
+++ b/docs/development.md
@@ -75,9 +75,11 @@ Last but not least have a look at [`lib/helpers/blogophon-handlebars-quoters.js`
 <!-- Test if two strings are equal -->
 {{#ifEquals tag 'new'}}It's new!{{/ifEquals}}
 
-<!--  Test if first string matches against rgeular expression -->
+<!--  Test if first string matches against regular expression -->
 {{#ifMatches tag '[Nn]ew'}}It's new!{{/ifMatches}}
 
+<!-- Export template variables to Javascript (e.g. for Google Tag Manager) -->
+<script>{{{dataLayer post.meta}}}</script>
 ```
 
 ### Favicons
diff --git a/lib/helpers/blogophon-handlebars-quoters.js b/lib/helpers/blogophon-handlebars-quoters.js
index c11c0dd9..7b40ee03 100644
--- a/lib/helpers/blogophon-handlebars-quoters.js
+++ b/lib/helpers/blogophon-handlebars-quoters.js
@@ -100,6 +100,33 @@ const blogophonHandlebarsQuoters = {
     return superString(text).niceShorten(maxChars, replaceString);
   },
 
+  /**
+   * [description]
+   * @param  {Object} dumpData  [description]
+   * @param  {String} options   [description]
+   * @return {String}           [description]
+   */
+  consoleDump: function(dumpData, options) {
+    let html = '<script>';
+    html += 'window.dumpData = window.dumpData || [];';
+    html += 'window.dumpData.push(' + options.fn(JSON.stringify(dumpData)) + ');';
+    html += 'console.log(window.dumpData[window.dumpData.length - 1]);';
+    html += '</script>';
+    return html;
+  },
+
+  /**
+   * [description]
+   * @param  {Object} dataLayer [description]
+   * @param  {String} options)  [description]
+   * @return {String}           [description]
+   */
+  dataLayer: function(dataLayer, options) {
+    let html = 'window.dataLayer = window.dataLayer || [];';
+    html += 'window.dataLayer.push(' + options.fn(JSON.stringify(dataLayer)) + ');';
+    return html;
+  },
+
   /**
    * @see https://stackoverflow.com/questions/34252817/handlebarsjs-check-if-a-string-is-equal-to-a-value
    * @param  {String}  haystack  [description]