如何打破节点js中的内部异步循环

Question

请参阅此代码为什么内部循环没有中断。 我只想在内部循环条件满足 的情况下推入新数组，并且应该中断内部循环的迭代，但外部循环应该照常进行迭代。

Inspired from

这里是我的代码：

var rows = [ RowDataPacket { 
            id: 1, 
            title: 'this is jg case', 
            description: 'this is reply to jg case', 
            type: 2, 
            created: Thu Mar 03 2016 12:50:20 GMT+0530 (IST), 
            group_id: '1,8', 
            AOI: '1,8' }, 
            RowDataPacket { 
            id: 2, 
            title: 'this is jg case', 
            description: 'this is another reply to jg case', 
            type: 1, 
            created: Thu Mar 03 2016 12:55:01 GMT+0530 (IST), 
            group_id: '3,9', 
            AOI: '1,8' }, 
            RowDataPacket { 
            id: 3, 
            title: 'this is jg case', 
            description: 'this is again another reply to jg case', 
            type: 1, 
            created: Thu Mar 03 2016 12:58:01 GMT+0530 (IST), 
            group_id: '3,8', 
            AOI: '1,8' }          
           ]; 


        var filteredRows = []; 

        async.each(rows, function(row, callback1){ 
         var eachRow = row.group_id.split(',').map(Number); 
         async.each(eachRow, function(group, callback2){ 

          if(AOI.indexOf(group) !== -1){ 
           filteredRows.push(row); 
           console.log(group,row); 
           var fakeErr = new Error(); 
           fakeErr.break = true; 
           return callback2(fakeErr); 
          } 

          callback2(); 

         }, function(err) { 

           if (err && err.break){ 
            console.log("should break the inner loop and continue for the next outer loop") 
            callback1(); 
           } 
           else 
            callback1(err); 
          }); 
        }, function(err) { 

          if (err) 
          callback(err, null); 

          callback(null, filteredRows); 
        }); 

预期输出：

var filteredRows = [ RowDataPacket { 
           id: 1, 
           title: 'this is jg case', 
           description: 'this is reply to jg case', 
           type: 2, 
           created: Thu Mar 03 2016 12:50:20 GMT+0530 (IST), 
           group_id: '1,8', 
           AOI: '1,8' }, 
           RowDataPacket { 
           id: 3, 
           title: 'this is jg case', 
           description: 'this is again another reply to jg case', 
           type: 1, 
           created: Thu Mar 03 2016 12:58:01 GMT+0530 (IST), 
           group_id: '3,8', 
           AOI: '1,8' }          
          ]; 

Answer 1

，而不是你的代码：

return callback2(fakeErr); 

您更改为：

callback2(fakeErr); 
return; 

你应该回到这里，如果不是，你的程序接收两个平行的回调

if (err) 
    callback(err, null); 
    // return here 
    return; 

callback(null, filteredRows); 

Answer 2

each()运行的迭代，你不能“打破循环”（当你这样做时，下一次迭代已经运行），则必须使用eachSeries()来控制异步流程：

// process rows in parallel 
async.each(rows, function(row, callback1) { 
    var eachRow = row.group_id.split(',').map(Number); 
    // for each row, process each group one at a time so you can break the loop 
    async.eachSeries(eachRow, function(group, callback2) { 
    // stuff 
    }); 
    // stuff 
});