八.批处理加载等待

export function reroute(pendings = [], eventArguments) {
    if (appChangeUnderway) {
        return new Promise((resolve, reject) => {
            peopleWaitingOnAppChange.push({
                resolve,
                reject,
                eventArguments
            })
        });
    }
    // ...
    if (started) {
        appChangeUnderway = true;
        return performAppChanges();
    }
    async function performAppChanges() {
        // ...
        finishUpAndReturn(); // 完成后批量处理在队列中的任务
    }
    function finishUpAndReturn(){
        appChangeUnderway = false;
        if(peopleWaitingOnAppChange.length > 0){
            const nextPendingPromises = peopleWaitingOnAppChange;
            peopleWaitingOnAppChange = [];
            reroute(nextPendingPromises)
        }
    }
}

这里的思路和Vue.nextTick一样，如果当前应用正在加载时，并且用户频繁切换路由。我们会将此时的reroute方法暂存起来，等待当前应用加载完毕后再次触发reroute渲染应用，从而节约性能!

最终别忘了，完成一轮应用加载时，需要手动触发用户注册的路由事件！

 callAllEventListeners();
 function callAllEventListeners() {
     pendingPromises.forEach((pendingPromise) => {
     	callCapturedEventListeners(pendingPromise.eventArguments);
     });
     callCapturedEventListeners(eventArguments);
 }