Javascript 从每个回调调用获取异步nodejs值
为什么结果总是未定义:请提供任何帮助。异步是ES7中的保留字,在以后实现时可能会给您带来问题。 你可能想考虑的是使用BabelAssic/等待ToHeTHER。 一些浏览器已经开始实现它了Javascript 从每个回调调用获取异步nodejs值,javascript,node.js,callback,async.js,Javascript,Node.js,Callback,Async.js,为什么结果总是未定义:请提供任何帮助。异步是ES7中的保留字,在以后实现时可能会给您带来问题。 你可能想考虑的是使用BabelAssic/等待ToHeTHER。 一些浏览器已经开始实现它了 var async = require('async'); var square = function (id, callback) { Business.prototype.getBusinessUser(id,function(userObject){ return callback(use
var async = require('async');
var square = function (id, callback) {
Business.prototype.getBusinessUser(id,function(userObject){
return callback(userObject);
});
};
async.eachSeries(findBusinessResult, function (businessObject, callback) {
//console.log("results from square");
var result = square(businessObject["id"] , function(result){
console.log(result);
});
callback(); // Alternatively: callback(new Error());
}, function (err,results) {
if (err) { throw err; }
console.log('Well done :-)!');
console.log(results);
});
我希望这将成为大多数ppl游戏规则改变者的解决方案。这使得ASYC java回调成为一种类似于与高效回调处理同步的东西。这是我的三天挑战。确实是JavaScript中的一个重大挑战,下面是如何使用承诺来解决这个问题
var square = id =>
new Promise(rs =>
Business.prototype.getBusinessUser(id, rs)
)
async search() {
for (let businessObject of findBusinessResult) {
let result = await square(businessObject.id)
console.log(result)
}
}
//在你的代码中
install bluebird
npm install bluebird --save
}
//现在,我如何在foreach循环中调用promise结果并将其值作为回调结果返回。这似乎是个疯狂的想法:
var Promise = require('bluebird'); //yeah awsome bird indeed :)
function extendBusinessObjectPromise(id,element) {
return new Promise(function(resolve, reject) {
Business.prototype.getBusinessUser( id ,function(userObject){
var extend = require('util')._extend;
mergedJson = userObject;
elements = element;
extend({},elements);
extend(elements,mergedJson);
global.businesssWithUsers.push(elements); //sahred object
resolve(global.businesssWithUsers)
})
})
终于成功了。干杯 看看
Person.prototype.getPersons = function(filter , callback) {
//this my own Bill count since i have one using one user account
global.businesssWithUsers = [];
models.PersonModel.findAll(filter_combined).then(function (findBusinessResult) {
global.businesssWithUsers = []
var extend = require('util')._extend;
var mergedJsonArray = [];
if (findBusinessResult==null) {
return callback(false,"no result found");
}
var promiseBusinessResult = null; //promise reslover :)
var findBusinessResult =JSON.parse(JSON.stringify(findBusinessResult));
findBusinessResult.forEach(function(eachElement) {
var id = element["userId"];
promiseBusinessResult = extendBusinessObjectPromise(id,element);
});
promiseBusinessResult.done(function(result){
callback(true,result); //pass the result to main function
});
}).catch(function (err) {
log.error(err["errors"][0]["message"])
callback(false,err["errors"][0]["message"])
return
})
}