ECMAScript 6

parascroll.js

@@ -1,27 +1,28 @@
-document.addEventListener("DOMContentLoaded", function(){
-    var CLASS_NAME = ".parallax-bg";
-    var ATTR_NAME = "data-bgurl";
-    var SCROLL_SPEED = 0.6;
+document.addEventListener("DOMContentLoaded", () => {
+    const className = ".parallax";
+    const attrName = "data-bgurl";
+    const scrollSpeed = 0.6;
+    const elements = document.querySelectorAll(className);
+    const targets = [];
 
-    var elements = document.querySelectorAll(CLASS_NAME);
-    var targets = [];
-    for (var i = 0; i < elements.length; i++) {
-        var elem = elements[i];
-        var url = elem.getAttribute(ATTR_NAME);
+    elements.forEach(elem => {
+        const url = elem.getAttribute(attrName);
         if (url) {
-            elem.style.backgroundImage = "url('"+url+"')";
+            elem.style.backgroundImage = "url('" + url + "')";
             elem.style.backgroundAttachment = "fixed";
             elem.style.backgroundSize = "cover";
             targets.push(elem);
         }
-    }
-    var callback = function() {
-        for (var i = 0; i < targets.length; i++) {
-            var rekt = targets[i].getBoundingClientRect();
+    });
+
+    const callback = () => {
+        for (let i = 0; i < targets.length; i++) {
+            const rect = targets[i].getBoundingClientRect();
             targets[i].style.backgroundPosition = "50%" +
-                rekt.top*SCROLL_SPEED + "px";
+                rect.top * scrollSpeed + "px";
         }
     };
+
     window.onscroll = callback;
     callback();
 });