Function resolveAsyncComponent

vue.js:3452–3565

(
        factory,  //函数工厂
        baseCtor, //构造函数或者vue
        context //vue实例化 对象
    )

    // 解析异步组件 更新数据
    function resolveAsyncComponent(
        factory,  //函数工厂
        baseCtor, //构造函数或者vue
        context //vue实例化 对象
    ) {
        console.log(factory);
        console.log(baseCtor);
        console.log(context);

        //如果  有错误     则返回错误信息
        if (isTrue(factory.error) && isDef(factory.errorComp)) {
            return factory.errorComp
        }
        //成功状态
        if (isDef(factory.resolved)) {
            return factory.resolved
        }
        //等待状态
        if (isTrue(factory.loading) && isDef(factory.loadingComp)) {
            return factory.loadingComp
        }
        //环境
        if (isDef(factory.contexts)) {
            // already pending 已经等待
            factory.contexts.push(context);
        } else {
            var contexts = factory.contexts = [context]; //转化成数组
            var sync = true;
            //渲染
            var forceRender = function () {
                for (var i = 0, l = contexts.length; i < l; i++) {
                    //更新数据 观察者数据
                    contexts[i].$forceUpdate();
                }
            };
            //成功 状态渲染
            var resolve = once(function (res) { //确保只是渲染一次
                // cache resolved
                factory.resolved = ensureCtor(res, baseCtor);
                // invoke callbacks only if this is not a synchronous resolve
                // (async resolves are shimmed as synchronous during SSR)
                //只有在这不是同步解析时才调用回调
                //(异步解析在SSR期间以同步的方式进行调整)
                if (!sync) {
                    //渲染组件更新数据
                    forceRender();
                }
            });
            //失败状态
            var reject = once(function (reason) {
                "development" !== 'production' && warn(
                    "Failed to resolve async component: " + (String(factory)) +
                    (reason ? ("\nReason: " + reason) : '')
                );
                if (isDef(factory.errorComp)) {
                    factory.error = true;
                    //渲染组件更新数据
                    forceRender();