Add FAQ ld json to article pages (#313)

* Add FAQ ld json to article pages

* code formatting

* code formatting

* only call faqjson if it is a blog page

* assign getCategory to a variable

* refactor function

cigaradvisor/scripts/linking-data.js

@@ -83,12 +83,60 @@ function addBlogPosts() {
   addLdJsonScript(document.querySelector('head'), ldjson);
 }
 
+/**
+ * Determines if the page contains a FAQ section and writes the LD JSON to the head
+ */
+function addFAQLdJson() {
+  const contentDivs = document.querySelectorAll('.default-content-wrapper');
+  // find the content div that contains a FAQ
+  for (let i = 0; i < contentDivs.length; i += 1) {
+    let isFAQPage = false;
+    const h2Elements = contentDivs[i].getElementsByTagName('h2');
+    // Does the div contain a faq section?
+    for (let j = 0; j < h2Elements.length; j += 1) {
+      if (h2Elements[j].id.includes('frequently-asked-questions')) {
+        isFAQPage = true;
+      }
+    }
+    if (isFAQPage) {
+      const ldjson = {
+        '@context': 'http://schema.org/',
+        '@type': 'FAQPage',
+        mainEntity: [],
+      };
+      // questions should be in the h3 elements, with the answers in the following element
+      const h3Elements = contentDivs[i].getElementsByTagName('h3');
+      for (let k = 0; k < h3Elements.length; k += 1) {
+        const QAEntity = {
+          '@type': 'Question',
+          name: h3Elements[k].textContent,
+          acceptedAnswer: {},
+        };
+        if (h3Elements[k].nextElementSibling) {
+          QAEntity.acceptedAnswer = {
+            '@type': 'Answer',
+            text: h3Elements[k].nextElementSibling.textContent,
+          };
+          // add question only if we found the answer
+          ldjson.mainEntity.push(QAEntity);
+        }
+      }
+      addLdJsonScript(document.querySelector('head'), ldjson);
+    }
+  }
+}
+
 export default function addLinkingData() {
   addOrg(document.querySelector('head'));
   if (window.location.pathname === '/cigaradvisor') {
     addBlogPosts();
-  } else if (window.location.pathname === getCategory(window.location.pathname)) {
-    addOrUpdateCollection();
-    window.addEventListener('hashchange', addOrUpdateCollection);
+  } else {
+    const category = getCategory(window.location.pathname);
+    if (window.location.pathname === category) {
+      addOrUpdateCollection();
+      window.addEventListener('hashchange', addOrUpdateCollection);
+    } else if (category) {
+      addFAQLdJson();
+    }
   }
 }