多异步请求

Question

好的，这里我是triyng在对象列表中进行一些验证，但是函数验证调用三个异步方法(向数据库发出请求).But，然后在paralel中，应用程序会给出错误500。

_.each(titlesToSave, function(title, index) {
    titleValidator.validateAsync(title, function (err) {
        if (err) {
            invalidTitles.push({index: index, error: err});
        }
        joinArray[index](); 
     }); 
});

var validateAsync = function (title, next) {
    async.parallel([
        function(callback){ checkCity(title.carrier.address, callback)},
        function(callback){ checkCity(title.beneficiary.address, callback)},
        function(callback){ checkCity(title.seller.address, callback)}
    ],
        function (err,results) {
            if(err){
                console.log('ERROR: ' +err);
                next(err);
            }else{
                console.log('Result: '+results);
                next();
            }
        });
};

var checkCity = function(adress, callback){
    var url = 'http://localhost:9000/api/city/'+adress.state+'/'+adress.city;
    if (adress) {
        http.get(url, function (res) {
            console.log('STATUS: ' + res.statusCode);
            res.on('data', function (chunk) {
                if (res.statusCode === 200) {
                    console.log(''+chunk);
                    callback(null, chunk);
                } else {
                    console.log('Invalid city: '+adress.city+', StatusCode: ' + res.statusCode);
                    callback(new Error('Invalid adress.'));
                }
            });
        }).on('error', function (error) {
            callback(error);
        });
    }
};

Answer 1

尝尝这个,

async.eachSeries(titlesToSave, function (title, index, next) {
  titleValidator.validateAsync(title, function (err) {
    if (err) {
      invalidTitles.push({index: index, error: err});
    }

    joinArray[index]();

    next(null);
  }); 
}, function (err) {
  console.log(err);
});