AngularJS错误:regeneratorRuntime未使用异步函数定义 [英] Angularjs Error: regeneratorRuntime is not defined with async function

问题描述

我正在与angularjs合作，我想执行一些与读取文件数据相关的代码，我想完全执行此功能，然后开始执行另一个代码块.

I am working with angularjs and i want to execute some code related to reading files data and i want execute this function totally then start to execute another block of code.

科学，我在控制器中使用了异步"关键字，但出现此错误

science i have used "async" keyword in my controller i got this error

regeneratorRuntime未定义

regeneratorRuntime is not defined

这是我的异步函数定义:

 async function fillFilesData() {
            if (uploader.queue.length) {
                uploader.queue.forEach(function (item) {
                    var reader = new FileReader();
                    reader.onloadend = function (e) {
                        console.log("about to encode");
                        var encoded_file = btoa(e.target.result.toString());
                        $scope.newAnnouncement.files.push({ fileName: item.file.name, encodedDatta: encoded_file });
                    };
                    reader.readAsBinaryString(item._file);

                });


            }

}

函数调用:

function calling:

$scope.add = function () {
            fillFilesData().then(function () {
//rest of my code here here
}
)};

推荐答案

如果babelrc中的目标浏览器/节点版本不支持异步和等待，则它们将被转换为生成器函数或类似它们的东西.没有安装babel-plugin-transform-runtime插件.有几种解决方法，即安装preset-env或babel-plugin-transform-runtime并将其包含在babelrc中-

Async and await are being transpiled into generator functions or something that resembles them if the target browser/node version in your babelrc doesn't support them and you don't have the babel-plugin-transform-runtime plugin installed. There's several ways this can be resolved, ie installing preset-env, or babel-plugin-transform-runtime and including them in your babelrc -- See here .

此代码块也存在另一个问题.异步功能不会返回可以解决的承诺.链接到异步函数的任何后续函数将立即执行，从而使异步/等待无用.也许这是100％的示例代码，但认为值得一提.

There's another issue with this block of code as well. The async function does not return a promise that can be resolved. Any subsequent function chained to the async function will be executed immediately rendering the async/await useless. Maybe this was 100% example code, but thought it was worth mentioning.

async function fillFilesData() {
            let deferred = $q.defer();
            if (uploader.queue.length) {
                uploader.queue.forEach(function (item) {
                    var reader = new FileReader();
                    reader.onloadend = function (e) {
                        console.log("about to encode");
                        var encoded_file = btoa(e.target.result.toString());
                        $scope.newAnnouncement.files.push({ fileName: item.file.name, encodedDatta: encoded_file });
                    };
                    reader.readAsBinaryString(item._file);

                });

             deferred.resolve(/*something*/);
            }else{
                deferred.resolve(/*whatever*/);
            }
            return deferred.promise;

}

$scope.add = function () {
            let res = await fillFilesData();
    yourFunctionToWait(res);
}
)};

这篇关于AngularJS错误:regeneratorRuntime未使用异步函数定义的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！