NodeJS async.parallel在另一個async.parallel

Question

在node.js中，我想有一個foreach async.parallel在另一個。不過，我得到了「回調已被稱爲」錯誤（看看我的代碼的評論）。我想要在內部完成後調用外部的回調函數。我怎樣才能做到這一點？

async = require("async"); 

var asyncTasks = []; 
var items = []; 
/* push elements to items */ 

items.forEach(function(item){ 
    var asyncTasks2 = []; 
    var items2 = []; 
    asyncTasks.push(function(callback2){ 
    item.someAsyncCall(function(){ 
     /* push elements to items2 */ 
     items2.forEach(function(item2){ 
      item2.someAsyncCall(function(){ 
      callback2();   
      }) 
     } 
     asyncTasks2.push(function(callback2){ 
     setTimeout(function(){ 
      callback2(); 
     }, 100000); 
     }); 
     async.parallel(asyncTasks2, function(){ 
      // All tasks are done now 
      doSomethingOnceAllAreDone(); 
      callback(); // callback was already called 
     }); 
    }); 
    }); 
}); 


asyncTasks.push(function(callback){ 
    setTimeout(function(){ 
    callback(); 
    }, 100000); 
}); 

async.parallel(asyncTasks, function(){ 
    // All tasks are done now 
    doSomethingOnceAllAreDone(); 
}); 

Answer 1

使用bluebird promise

var Promise = require('bluebird'); 
var items = []; 
return Promise.map(items, function(item){ 
    var items2 = []; 
    return Promise.map(items2, function(item2){ 
     return item2.someAsyncCall(); 
    }) 
    .then(function(){ 
     return doSomethingOnceItems2AreDone();   
    }); 
}) 
.then(function(){ 
    return doSomethingOnceItems1AreDone();  
});