Helper to figure out if a rendered element is truncated

truncated-node.js

// Working example in jsfiddle: https://jsfiddle.net/Ld2pjabu/5/

// Helper to get the width of any element
function getElementWidth(element) {
  return (element && element.getBoundingClientRect) ? element.getBoundingClientRect().width : 0;
}

// Helper to calculate an unbound width
function getUnboundWidth(element) {
  // Clone the element in question
  var clonedElement = element.cloneNode(true);
  // Add inline styles to make the element extend to the width it needs
  clonedElement.style.width = 'auto';
  clonedElement.style.visibility = 'hidden';
  // Append the element to the body to be rendered
  document.body.append(clonedElement);
  var elementWidth = getElementWidth(clonedElement);
  // Remove the cloned element from the DOM
  clonedElement.parentNode.removeChild(clonedElement);
  return elementWidth;
}

// Returns true or false depending on if the element as currently renedered is truncated
function isTruncatedElement(element) {
  var renderedWidth = getElementWidth(element);
  var fullWidth = getUnboundWidth(element)

  return (renderedWidth < fullWidth);
}