Question

我想在我的服务中使用async.series（[]），然后将结果返回给Controller。但是，似乎async.series的可选回调函数不会等到任务完成后再返回到控制器。

/* In Services */
getFunction: function(userInput, callback) {
  var results = {};
  
  async.series([
    //1: This function get a list JSON dataset of id and other attributes
    function(callback) {
      //Call a function to call API by using the userInput, return function(error, JSONdataset1)
      //If error, return callback(error)
      //Else results = JSON.parse(dataset1);
       callback(null, JSON.stringify(results));
    },
    //2: This function get a JSON object by input the id result from above function
    //I am not sure I should use for loop here as well, can someone advise me please!
    function(callback) {
      for(var result in results) {
        //Call another function to call API by using the id in the returned results, return function(error, JSONdataset2)
        //If error, return callback(error)
        //Else
        var aName = JSON.parse(JSONdataset2);
        results[result].name = JSON.parse(JSON.stringify(aName.attribute));
      }
      callback(null, JSON.stringify(results));
    }
  ],
  //res = [JSON.stringify(results), JSON.stringify(results)] and result should return to Controller
  //The problem is the callback doesn't wait above functions finish before return.
  function(error, res) {
    if(error) { return callback(error, null); }
    else { return callback(null, res); }
  });
  
}

Answer 1

在类似的情况下，我会使用async.each()函数，例如

async.each(results, function(result){
    var aName = JSON.parse(JSONdataset2);
    results[result].name = JSON.parse(JSON.stringify(aName.attribute));
    callback();
}, function(err){
    if(err) callback(err,null);
    else callback(null, JSON.stringify(results));
})

这将确保在调用属于您的系列函数的回调之前迭代每个结果。

Answer 2

Instead of the code I posted earlier, I used async.waterfall.

Sails.js如何在async.series（[]）中使用for循环？

2 个答案: