Function off

src/js/utils/events.js:352–408

(elem, type, fn)

 *        type.
 */
export function off(elem, type, fn) {
  // Don't want to add a cache object through getElData if not needed
  if (!DomData.has(elem)) {
    return;
  }

  const data = DomData.get(elem);

  // If no events exist, nothing to unbind
  if (!data.handlers) {
    return;
  }

  if (Array.isArray(type)) {
    return _handleMultipleEvents(off, elem, type, fn);
  }

  // Utility function
  const removeType = function(el, t) {
    data.handlers[t] = [];
    _cleanUpEvents(el, t);
  };

  // Are we removing all bound events?
  if (type === undefined) {
    for (const t in data.handlers) {
      if (Object.prototype.hasOwnProperty.call(data.handlers || {}, t)) {
        removeType(elem, t);
      }
    }
    return;
  }

  const handlers = data.handlers[type];

  // If no handlers exist, nothing to unbind
  if (!handlers) {
    return;
  }

  // If no listener was provided, remove all listeners for type
  if (!fn) {
    removeType(elem, type);
    return;
  }

  // We're only removing a single handler
  if (fn.guid) {
    for (let n = 0; n < handlers.length; n++) {
      if (handlers[n].guid === fn.guid) {
        handlers.splice(n--, 1);
      }
    }
  }

  _cleanUpEvents(elem, type);
}