Reloading Hypothesis annotations on hash change

hypothesis-hashchange.js

// Function to check whether an anchor is currently attached to the document.
function isAttached(anchor) {
  // If there are no highlights it is not attached at all.
  if (anchor.highlights == null) {
    return false;
  }

  // Check if any of highlights have since been removed from the document.
  for (var i = 0 ; i < anchor.highlights.length ; i++) {
    if (!document.contains(anchor.highlights[i])) {
      return false;
    }
  }

  // Otherwise, this anchor appears to be fully attached.
  return true;
}


// Function to anchor all detached annotations.
function reanchorAnnotations() {
  var annotator = window.annotator;
  var anchors = annotator.anchors.slice();

  for (var i = 0 ; i < anchors.length ; i++) {
    var anchor = anchors[i];
    var annotation = anchor.annotation;

    if (isAttached(anchor)) {
      annotator.detach(annotation);  // Clean up any remaining highlights.
      annotator.anchor(annotation);  // Then anchor and highlight anew.
    }
  }
}


window.addEventListener("hashchange", reanchorAnnotations, false);