Question

188

node.js async.eachSeries calling final callback too early

rated 0 times [ 195] [ 7] / answers: 1 / hits: 11639 / 11 Years ago, wed, february 12, 2014, 12:00:00

This is what I want: I have a large array called results. Each item in that array I want to put in my iteration function and have it saved to my mongoDB (I omitted some steps here as well which are not important). After every single one of those items has been saved to the database (or refused) I want console.log to display 'All done'. Unfortunately All done is displayed almost immediately after calling the series while everything else is still processing. How do I do this right?

I am using mongoose with a model called 'light' and for readability I omitted all err messages from the code. I use node-async for the eachSeries part

var async = require('async');    

var results = [very big array]

var iteration = function(row,callbackDone) {

  light.find({data: row.data}, function (err,entry) {

    if(entry.length) {

      callbackDone();

      return console.log(entry + ' already exists');

    }

    var newEntry = new light(row);

    newEntry.save(function (err,doc) {

      console.log(entry + ' saved');

      callbackDone();

    });

  });

};



async.eachSeries(results,iteration, function (err) {

  console.log('All done');

});

Answers

Only authorized users can answer the question. Please sign in first, or register a free account.

kenyonc

Add To Favorites

Follow

Total Points: 235

Total Questions: 106

Total Answers: 125

Location: Bangladesh

Member since Sat, Jan 23, 2021

3 Years ago

answered 11 Years ago cruzs · Accepted Answer

(An answer, not a comment, because the text was too long...)

I'm using async for something too and your question puzzled me. I tried the code below, getting the results even further down. It worked fine for me. (async 0.2.9). Even changing my timeout delays to 0.

The only thing that looked odd was the if(entry.length) block printed console information after the callback. If you were getting a lot of already exists messages I could see potentially them coming later - but that doesn't sound like what you are describing.

var async = require('async');  

var console = require('console');

var results = [ ];

results.push( {id:1,data:'a'} );

results.push( {id:2,data:'b'} );

results.push( {id:3,data:'c'} );

results.push( {id:4,data:'d'} );



function doFind( obj, callback ) {

  setTimeout( function() {

    console.log( finding id= + obj.data.id );

    obj.data.length = obj.data.id % 2;

    callback( null, obj.data );

  }, 500 );

}



function light( obj ) {

  this.id = obj.id;

  this.data = obj.data;

  this.save = function( callback ) {

    setTimeout( function() {

      console.log( saving id= + obj.id );

      callback( null, this );

    }, 500 );

  };

}



var iteration = function(row,callbackDone) {

  doFind({data: row}, function (err,entry) {

    if(entry.length) {

      callbackDone(); 

      return console.log( 'id=' + entry.id + ' already exists');

    }

    var newEntry = new light(row);

    newEntry.save(function (err,doc) {

      console.log( 'id=' + entry.id + ' saved');

      callbackDone();

    });

  });

};



async.eachSeries(results, iteration, function (err) {

  console.log('All done');

});

Results

finding id=1

id=1 already exists

finding id=2

saving id=2

id=2 saved

finding id=3

id=3 already exists

finding id=4

saving id=4

id=4 saved

All done