Function _cleanUpEvents

src/js/utils/events.js:25–56

* Clean up the listener cache and dispatchers * * @param {Element|Object} elem * Element to clean up * * @param {string} type * Type of event to clean up

(elem, type)

 *        Type of event to clean up
 */
function _cleanUpEvents(elem, type) {
  if (!DomData.has(elem)) {
    return;
  }
  const data = DomData.get(elem);

  // Remove the events of a particular type if there are none left
  if (data.handlers[type].length === 0) {
    delete data.handlers[type];
    // data.handlers[type] = null;
    // Setting to null was causing an error with data.handlers

    // Remove the meta-handler from the element
    if (elem.removeEventListener) {
      elem.removeEventListener(type, data.dispatcher, false);
    } else if (elem.detachEvent) {
      elem.detachEvent('on' + type, data.dispatcher);
    }
  }

  // Remove the events object if there are no types left
  if (Object.getOwnPropertyNames(data.handlers).length <= 0) {
    delete data.handlers;
    delete data.dispatcher;
    delete data.disabled;
  }

  // Finally remove the element data if there is no data left
  if (Object.getOwnPropertyNames(data).length === 0) {
    DomData.delete(elem);
  }
}

/**
 * Loops through an array of event types and calls the requested method for each type.