Get text length

measure-width.js

//
// Get text width of a specified element.
//
function measureWidth(el, str) {
  // Create dummy elem
  var div = documtent.createElement('div');
  
  // Append
  document.body.appendChild(div);
    
  // Mirror input
  var styles = window.getComputedStyle(el).cssText;
  div.setAttribute("style", styles);
    
  // Setup to grab width
  div.style.width = "auto";
  div.style.position = "absolute";
  div.style.left = '-1000px';
  div.style.top = '-1000px';
  div.innerHTML = str;
    
  // Get width
  var result = div.clientWidth;
    
  // Clean up
  document.body.removeChild(div);
  div = null;
    
  // Return result
  return result;
}