feat: Show Table of Contents in the article sidebar (#7085)

app/javascript/packs/portal.js

@@ -1,35 +1,9 @@
-// This file is automatically compiled by Webpack, along with any other files
-// present in this directory. You're encouraged to place your actual application logic in
-// a relevant structure within app/javascript and only use these pack files to reference
-// that code so that it will be compiled.
-
-import Vue from 'vue';
 import Rails from '@rails/ujs';
 import Turbolinks from 'turbolinks';
-import PublicArticleSearch from '../portal/components/PublicArticleSearch.vue';
-
-import { navigateToLocalePage } from '../portal/portalHelpers';
-
 import '../portal/application.scss';
+import { InitializationHelpers } from '../portal/portalHelpers';
 
 Rails.start();
 Turbolinks.start();
 
-const initPageSetUp = () => {
-  navigateToLocalePage();
-  const isSearchContainerAvailable = document.querySelector('#search-wrap');
-  if (isSearchContainerAvailable) {
-    new Vue({
-      components: { PublicArticleSearch },
-      template: '<PublicArticleSearch />',
-    }).$mount('#search-wrap');
-  }
-};
-
-document.addEventListener('DOMContentLoaded', () => {
-  initPageSetUp();
-});
-
-document.addEventListener('turbolinks:load', () => {
-  initPageSetUp();
-});
+document.addEventListener('turbolinks:load', InitializationHelpers.onLoad);

app/javascript/portal/application.scss

@@ -16,3 +16,21 @@ body {
   -webkit-font-smoothing: antialiased;
   height: 100%;
 }
+
+
+// Taking these utils from tailwind 3.x.x, need to remove once we upgrade
+.scroll-mt-24 {
+  scroll-margin-top: 6rem;
+}
+
+.top-24 {
+  top: 6rem;
+}
+
+.heading {
+  &:hover {
+    a {
+      visibility: visible;
+    }
+  }
+}

app/javascript/portal/components/TableOfContents.vue

@@ -0,0 +1,70 @@
+<template>
+  <div class="hidden lg:block flex-1 scroll-mt-24 pl-4">
+    <div v-if="rows.length > 0" class="sticky top-24 py-12 overflow-auto">
+      <nav class="max-w-2xl">
+        <h2
+          id="on-this-page-title"
+          class="text-slate-800 font-semibold tracking-wide border-b mb-3 leading-7"
+        >
+          {{ tocHeader }}
+        </h2>
+        <ol role="list" class="mt-4 space-y-3 text-base">
+          <li v-for="element in rows" :key="element.slug" class="leading-6">
+            <p :class="getClassName(element)">
+              <a
+                :href="`#${element.slug}`"
+                data-turbolinks="false"
+                class="text-base text-slate-800 cursor-pointer"
+              >
+                {{ element.title }}
+              </a>
+            </p>
+          </li>
+        </ol>
+      </nav>
+    </div>
+  </div>
+</template>
+<script>
+export default {
+  props: {
+    rows: {
+      type: Array,
+      default: () => [],
+    },
+  },
+  computed: {
+    tocHeader() {
+      return window.portalConfig.tocHeader;
+    },
+    h1Count() {
+      return this.rows.filter(el => el.tag === 'h1').length;
+    },
+    h2Count() {
+      return this.rows.filter(el => el.tag === 'h2').length;
+    },
+  },
+  methods: {
+    getClassName(el) {
+      if (el.tag === 'h1') {
+        return '';
+      }
+      if (el.tag === 'h2') {
+        if (this.h1Count > 0) {
+          return 'ml-2';
+        }
+        return '';
+      }
+
+      if (el.tag === 'h3') {
+        if (!this.h1Count && !this.h2Count) {
+          return '';
+        }
+        return 'ml-8';
+      }
+
+      return '';
+    },
+  },
+};
+</script>

app/javascript/portal/portalHelpers.js

@@ -1,13 +1,79 @@
-export const navigateToLocalePage = () => {
-  const allLocaleSwitcher = document.querySelector('.locale-switcher');
+import slugifyWithCounter from '@sindresorhus/slugify';
+import Vue from 'vue';
 
-  if (!allLocaleSwitcher) {
-    return false;
-  }
+import PublicArticleSearch from './components/PublicArticleSearch.vue';
+import TableOfContents from './components/TableOfContents.vue';
 
-  const { portalSlug } = allLocaleSwitcher.dataset;
-  allLocaleSwitcher.addEventListener('change', event => {
-    window.location = `/hc/${portalSlug}/${event.target.value}/`;
+export const getHeadingsfromTheArticle = () => {
+  const rows = [];
+  const articleElement = document.getElementById('cw-article-content');
+  articleElement.querySelectorAll('h1, h2, h3').forEach(element => {
+    const slug = slugifyWithCounter(element.innerText);
+    element.id = slug;
+    element.className = 'scroll-mt-24 heading';
+    element.innerHTML += `<a class="invisible text-slate-600 ml-3" href="#${slug}" title="${element.innerText}" data-turbolinks="false">#</a>`;
+    rows.push({
+      slug,
+      title: element.innerText,
+      tag: element.tagName.toLowerCase(),
+    });
   });
-  return false;
+  return rows;
+};
+
+export const InitializationHelpers = {
+  navigateToLocalePage: () => {
+    const allLocaleSwitcher = document.querySelector('.locale-switcher');
+
+    if (!allLocaleSwitcher) {
+      return false;
+    }
+
+    const { portalSlug } = allLocaleSwitcher.dataset;
+    allLocaleSwitcher.addEventListener('change', event => {
+      window.location = `/hc/${portalSlug}/${event.target.value}/`;
+    });
+    return false;
+  },
+
+  initalizeSearch: () => {
+    const isSearchContainerAvailable = document.querySelector('#search-wrap');
+    if (isSearchContainerAvailable) {
+      new Vue({
+        components: { PublicArticleSearch },
+        template: '<PublicArticleSearch />',
+      }).$mount('#search-wrap');
+    }
+  },
+
+  initializeTableOfContents: () => {
+    const isOnArticlePage = document.querySelector('#cw-hc-toc');
+    if (isOnArticlePage) {
+      new Vue({
+        components: { TableOfContents },
+        data: { rows: getHeadingsfromTheArticle() },
+        template: '<table-of-contents :rows="rows" />',
+      }).$mount('#cw-hc-toc');
+    }
+  },
+
+  initialize: () => {
+    InitializationHelpers.navigateToLocalePage();
+    InitializationHelpers.initalizeSearch();
+    InitializationHelpers.initializeTableOfContents();
+  },
+
+  onLoad: () => {
+    InitializationHelpers.initialize();
+    if (window.location.hash) {
+      if ('scrollRestoration' in window.history) {
+        window.history.scrollRestoration = 'manual';
+      }
+
+      const a = document.createElement('a');
+      a.href = window.location.hash;
+      a['data-turbolinks'] = false;
+      a.click();
+    }
+  },
 };

app/javascript/portal/specs/portal.spec.js

@@ -1,4 +1,4 @@
-import { navigateToLocalePage } from '../portalHelpers';
+import { InitializationHelpers } from '../portalHelpers';
 
 describe('#navigateToLocalePage', () => {
   it('returns correct cookie name', () => {
@@ -14,7 +14,7 @@ describe('#navigateToLocalePage', () => {
         callback({ target: { value: 1 } });
       });
 
-    navigateToLocalePage();
+    InitializationHelpers.navigateToLocalePage();
     expect(allLocaleSwitcher.addEventListener).toBeCalledWith(
       'change',
       expect.any(Function)