From 2074fa67fae8812baa0d62889bb332540c30778e Mon Sep 17 00:00:00 2001
From: Nick Van Doorn <vandoorn.nick@gmail.com>
Date: Thu, 11 Oct 2018 02:42:12 -0700
Subject: Improve comments & assign node

---
 projects/1-colour-shift/main.js | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/projects/1-colour-shift/main.js b/projects/1-colour-shift/main.js
index 53a5d4f..8fc7609 100644
--- a/projects/1-colour-shift/main.js
+++ b/projects/1-colour-shift/main.js
@@ -9,17 +9,22 @@ function computeRgb(x, y, width, height) {
 // This will be an array of nodes since we are
 // using class name (array may have length 0 or 1)
 let attentionNodes
+// Make sure we wait until the page is ready.
+// Querying the DOM before the page is ready
+// will result in queries returning null/empty array
 window.onload = function() {
-  document.getElementsByClassName('attention')
+  attentionNodes = document.getElementsByClassName('attention')
 }
 document.onmousemove = function(event) {
-  // iterate over each node and update its style
+  // calculate the color once (will be used
+  // for all nodes)
   let color = computeRgb(
     event.pageX,
     event.pageY,
     window.innerWidth,
     window.innerHeight
   )
+  // iterate over each node and update its style
   for (let node of attentionNodes) {
     node.style.color = color
   }
-- 
cgit v1.2.3