Optimize load time

content/assets/js/main.js

@@ -0,0 +1,74 @@
+function setVisibleTags(){
+  var tocLinks = document.querySelectorAll("#sidebar a:link, a:visited");
+   for(var i = 0; i < tocLinks.length; i++){
+     if(localStorage.getItem(tocLinks[i].getAttribute("href")) != null){
+       tocLinks[i].parentNode.classList.add("visited");
+     }
+   }
+}
+
+function updateSidebar(notransition) {
+  if (notransition) {
+    document.querySelectorAll("#sidebar")[0].classList.add("notransition");
+    document.querySelectorAll("article")[0].classList.add("notransition");
+  }
+  localStorage.setItem("openside", window.sidebarExpanded);
+  if (!window.sidebarExpanded) {
+    document.querySelectorAll("#sidebar")[0].classList.add("collapsed");
+    document.querySelectorAll("article")[0].classList.add("expanded");
+  } else {
+    document.querySelectorAll("#sidebar")[0].classList.remove("collapsed");
+    document.querySelectorAll("article")[0].classList.remove("expanded");
+  }
+  if (notransition) {
+    setTimeout(function(){
+      document.querySelectorAll("#sidebar")[0].classList.remove("notransition");
+      document.querySelectorAll("article")[0].classList.remove("notransition");
+    }, 100);
+  }
+}
+
+function sidebarClick() {
+  window.sidebarExpanded = !window.sidebarExpanded;
+  updateSidebar(false);
+}
+
+function getNextPrev() {
+  // thanks iznogoodd from #nim @ freenode.net
+  var links = document.querySelectorAll('#sidebar a[href]');
+
+  var nav = {prev: null, next: null};
+  for(var i = 0; i < links.length; i++){
+    var item = links.item(i);
+    if(item && item.getAttribute('href') === window.location.pathname){
+      nav.prev = links.item(i - 1) && links.item(i - 1).getAttribute('href');
+      nav.next = links.item(i + 1) && links.item(i + 1).getAttribute('href');
+      return nav;
+    }
+  }
+}
+
+function updateNextPrevButtons() {
+  var nav = getNextPrev();
+
+  var prev = document.getElementById("arrow-prev");
+  var next = document.getElementById("arrow-next");
+
+  if (nav.prev != null) { prev.classList.remove("disabled"); prev.href = nav.prev; }
+  if (nav.next != null) { next.classList.remove("disabled"); next.href = nav.next; }
+}
+
+
+var isMobile = window.screen.width < 720;
+if (localStorage.getItem("openside") === null) {
+  window.sidebarExpanded = !isMobile;
+} else {
+  window.sidebarExpanded = (localStorage.getItem("openside") === "true");
+}
+
+localStorage.setItem(window.location.pathname, true);
+window.onload = function(){
+  updateSidebar(true);
+  setVisibleTags();
+  updateNextPrevButtons();
+}