Function add

static/vuejs/vue.common.js:1821–1827

(event, fn, once$$1)

var target;

function add (event, fn, once$$1) {
  if (once$$1) {
    target.$once(event, fn);
  } else {
    target.$on(event, fn);
  }
}

function remove$1 (event, fn) {
  target.$off(event, fn);