From 68c05b97b26ef4966da58933f59834e6bb640059 Mon Sep 17 00:00:00 2001
From: James Panther <4462786+jpanther@users.noreply.github.com>
Date: Thu, 28 Oct 2021 15:32:27 +1100
Subject: [PATCH] =?UTF-8?q?=E2=9C=A8=20Add=20chart=20shortcode?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 CHANGELOG.md                           |  1 +
 README.md                              |  1 +
 exampleSite/content/docs/shortcodes.md | 36 +++++++++++++++++++++++++-
 layouts/partials/head.html             | 17 ++++++++++++
 layouts/shortcodes/chart.html          | 12 +++++++++
 5 files changed, 66 insertions(+), 1 deletion(-)
 create mode 100644 layouts/shortcodes/chart.html

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 06659675..87350fb7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 ### Added
 
+- Chart.js support using `chart` shortcode
 - French translation ([#18](https://github.com/jpanther/congo/pull/18))
 - Grouping by year can now be specificed in front matter on list pages
 
diff --git a/README.md b/README.md
index 7608d8e6..5c10ad75 100644
--- a/README.md
+++ b/README.md
@@ -20,6 +20,7 @@ Congo is designed to be a simple, lightweight theme for [Hugo](https://gohugo.io
 - Flexible with any content types, taxonomies and menus
 - Ability to link to posts on third-party websites
 - Diagrams and visualisations using Mermaid
+- Charts using Chart.js
 - SVG icons from FontAwesome 5
 - Heading anchors, Buttons, Badges and more
 - HTML and Emoji support in articles 🎉
diff --git a/exampleSite/content/docs/shortcodes.md b/exampleSite/content/docs/shortcodes.md
index e8baa7f8..55d94f1d 100644
--- a/exampleSite/content/docs/shortcodes.md
+++ b/exampleSite/content/docs/shortcodes.md
@@ -59,6 +59,40 @@ Call to action
 Call to action
 {{< /button >}}
 
+## Chart
+
+`chart` uses the Chart.js library to embed charts into articles using simple structured data. It supports a number of [different chart styles](https://www.chartjs.org/docs/latest/samples/) and everything can be configured from within the shortcode. Simply provide the chart parameters between the shortcode tags and Chart.js will do the rest.
+
+Refer to the [official Chart.js docs](https://www.chartjs.org/docs/latest/general/) for details on syntax and supported chart types.
+
+**Example:**
+
+```js
+{{</* chart */>}}
+type: 'bar',
+data: {
+  labels: ['Tomato', 'Blueberry', 'Banana', 'Lime', 'Orange'],
+  datasets: [{
+    label: '# of votes',
+    data: [12, 19, 3, 5, 2, 3],
+  }]
+}
+{{</* /chart */>}}
+```
+
+<!-- prettier-ignore-start -->
+{{< chart >}}
+type: 'bar',
+data: {
+  labels: ['Tomato', 'Blueberry', 'Banana', 'Lime', 'Orange'],
+  datasets: [{
+    label: '# of votes',
+    data: [12, 19, 3, 5, 3],
+  }]
+}
+{{< /chart >}}
+<!-- prettier-ignore-end -->
+
 ## Icon
 
 `icon` outputs an SVG icon and takes the icon name as its only parameter. The icon is scaled to match the current text size.
@@ -93,7 +127,7 @@ When life gives you lemons, make lemonade.
 
 ## Mermaid
 
-`mermaid` allows you to draw detailed diagrams and visualisations using text. It uses MermaidJS under the hood and supports a wide variety of diagrams, charts and other output formats.
+`mermaid` allows you to draw detailed diagrams and visualisations using text. It uses Mermaid under the hood and supports a wide variety of diagrams, charts and other output formats.
 
 Simply write your Mermaid syntax within the `mermaid` shortcode and let the plugin do the rest.
 
diff --git a/layouts/partials/head.html b/layouts/partials/head.html
index f9eb9534..13c270d5 100644
--- a/layouts/partials/head.html
+++ b/layouts/partials/head.html
@@ -116,6 +116,23 @@
       </script>
     {{ end }}
   {{ end }}
+  {{/* Chart */}}
+  {{ if .Page.HasShortcode "chart" }}
+    {{ $chartJS := resources.Get "vendor/chart/chart.min.js" }}
+    {{ if $chartJS }}
+      {{ $chartJS := $chartJS | resources.Fingerprint "sha512" }}
+      <script defer src="{{ $chartJS.RelPermalink }}" integrity="{{ $chartJS.Data.Integrity }}"></script>
+      <script>
+        document.addEventListener('DOMContentLoaded', (event) => {
+          function css(name) {
+            return getComputedStyle(document.documentElement).getPropertyValue(name);
+          }
+          Chart.defaults.font.size = 14
+          Chart.defaults.backgroundColor = css("--color-primary-300")
+        });
+      </script>
+    {{ end }}
+  {{ end }}
   {{/* Analytics */}}
   {{ partialCached "analytics.html" .Site }}
   {{/* Extend head - eg. for custom analytics scripts, etc. */}}
diff --git a/layouts/shortcodes/chart.html b/layouts/shortcodes/chart.html
new file mode 100644
index 00000000..bcfc4d2a
--- /dev/null
+++ b/layouts/shortcodes/chart.html
@@ -0,0 +1,12 @@
+<div class="chart">
+  {{ $id := delimit (shuffle (seq 1 9)) "" }}
+  <canvas id="{{ $id }}"></canvas>
+  <script>
+    document.addEventListener("DOMContentLoaded", (event) => {
+      const ctx = document.getElementById("{{ $id }}");
+      const chart = new Chart(ctx, {
+        {{ .Inner | safeJS }}
+      });
+    });
+  </script>
+</div>