<article><canvas width="100" height="100"></canvas></article>
  <script>

  buildSpinner({ x : 50, y : 50, size : 20, degrees : 30 });  

  function buildSpinner(data) {  

var canvas = document.createElement('canvas');  
canvas.height = 100;  
canvas.width = 300;  
document.getElementsByTagName('article')[0].appendChild(canvas);  
var ctx = canvas.getContext("2d"),  
i = 0, degrees = data.degrees, loops = 0, degreesList = [];  

for (i = 0; i < degrees; i++) {  
degreesList.push(i);  
}  

// reset  
i = 0;  

// so I can kill it later  
window.canvasTimer = setInterval(draw, 1000/degrees);

function reset() {  
ctx.clearRect(0,0,100,100); // clear canvas  

var left = degreesList.slice(0, 1);  
var right = degreesList.slice(1, degreesList.length);  
degreesList = right.concat(left);  
}  

function draw() {  
var c, s, e;  

var d = 0;  

if (i == 0) {  
reset();  
}  

ctx.save();  

d = degreesList[i];  
c = Math.floor(255/degrees*i);  
ctx.strokeStyle = 'rgb(' + c + ', ' + c + ', ' + c + ')';  
ctx.lineWidth = data.size;  
ctx.beginPath();  
s = Math.floor(360/degrees*(d));  
e = Math.floor(360/degrees*(d+1)) - 1;  

ctx.arc(data.x, data.y, data.size, (Math.PI/180)*s, (Math.PI/180)*e, false);  
ctx.stroke();  

ctx.restore();  

i++;  
if (i >= degrees) {  
i = 0;  
}  
}
  }  
  </script>