Function leave

static/vuejs/vue.esm.js:6513–6613

(vnode, rm)

}

function leave (vnode, rm) {
  var el = vnode.elm;

  // call enter callback now
  if (el._enterCb) {
    el._enterCb.cancelled = true;
    el._enterCb();
  }

  var data = resolveTransition(vnode.data.transition);
  if (!data) {
    return rm()
  }

  /* istanbul ignore if */
  if (el._leaveCb || el.nodeType !== 1) {
    return
  }

  var css = data.css;
  var type = data.type;
  var leaveClass = data.leaveClass;
  var leaveToClass = data.leaveToClass;
  var leaveActiveClass = data.leaveActiveClass;
  var beforeLeave = data.beforeLeave;
  var leave = data.leave;
  var afterLeave = data.afterLeave;
  var leaveCancelled = data.leaveCancelled;
  var delayLeave = data.delayLeave;
  var duration = data.duration;

  var expectsCSS = css !== false && !isIE9;
  var userWantsControl = getHookArgumentsLength(leave);

  var explicitLeaveDuration = toNumber(
    isObject(duration)
      ? duration.leave
      : duration
  );

  if (process.env.NODE_ENV !== 'production' && explicitLeaveDuration != null) {
    checkDuration(explicitLeaveDuration, 'leave', vnode);
  }

  var cb = el._leaveCb = once(function () {
    if (el.parentNode && el.parentNode._pending) {
      el.parentNode._pending[vnode.key] = null;
    }
    if (expectsCSS) {
      removeTransitionClass(el, leaveToClass);
      removeTransitionClass(el, leaveActiveClass);
    }
    if (cb.cancelled) {
      if (expectsCSS) {
        removeTransitionClass(el, leaveClass);
      }
      leaveCancelled && leaveCancelled(el);
    } else {