Function trackValueOnNode

docs/index.js:4490–4531

(node)

  );
}
function trackValueOnNode(node) {
  var valueField = isCheckable(node) ? "checked" : "value",
    descriptor = Object.getOwnPropertyDescriptor(
      node.constructor.prototype,
      valueField
    ),
    currentValue = "" + node[valueField];
  if (
    !node.hasOwnProperty(valueField) &&
    "undefined" !== typeof descriptor &&
    "function" === typeof descriptor.get &&
    "function" === typeof descriptor.set
  ) {
    var get = descriptor.get,
      set = descriptor.set;
    Object.defineProperty(node, valueField, {
      configurable: !0,
      get: function () {
        return get.call(this);
      },
      set: function (value) {
        currentValue = "" + value;
        set.call(this, value);
      }
    });
    Object.defineProperty(node, valueField, {
      enumerable: descriptor.enumerable
    });
    return {
      getValue: function () {
        return currentValue;
      },
      setValue: function (value) {
        currentValue = "" + value;
      },
      stopTracking: function () {
        node._valueTracker = null;
        delete node[valueField];
      }
    };
  }
}
function track(node) {
  node._valueTracker || (node._valueTracker = trackValueOnNode(node));
}