How to save and load a custom property on an annotation?

[Matt Parizeau]

Q:

How do I save and load a custom property on an annotation? I want the property to be preserved when I load the annotations from my server.

A:

You can extend the serialize and deserialize functions of Annotations.Annotation so that it adds a custom attribute to exported XFDF. For example:

var serialize = Annotations.Annotation.prototype.serialize;
Annotations.Annotation.prototype.serialize = function() {
  var el = serialize.apply(this, arguments);
  if (this.myCustomAttribute) {
    el.setAttribute('attribute-name', this.myCustomAttribute);
  }
  return el;
};

var deserialize = Annotations.Annotation.prototype.deserialize;
Annotations.Annotation.prototype.deserialize = function(el) {
  deserialize.apply(this, arguments);
  this.myCustomAttribute = el.getAttribute('attribute-name');
  return el;
};