Node.js for loop with http requests

Question

for api request I go trough some arrays:

'mail', '20.03.2017 05:32', '11.07.2017 03:44', '2', '0', '2', '0', '4', '3', '46' ]

for each array I do 3 nested request But now I have the problem that my index for the requests is sometimes wrong. I think that my loop is faster than the request. How can I take the following way:

Start for loop index = 1
make api call 1 with index 1
wait for api call 1 response
make api call 2 with index 1
wait for response of api call 2
make api call 3 with index 1
wait for response of api call 3
index++
make api call 1 with index 2 ......

for (var i = 1; i <= (csvData.length-1); i++){


var options = { method: 'GET',
  url: 'https://api.pipedrive.com/v1/persons/find',
  qs: 
   { term: csvData[i][0],
     start: '0',
     search_by_email: '1',
     api_token: '' },
  headers: 
   { 'postman-token': '',
     'cache-control': 'no-cache' } };

request(options, function (error, response, body) {
  if (error) throw new Error(error);

  
  var user = JSON.parse(body);
    console.log("-->User gefunden<--");
    console.log("-->User: "+user.data[0].name+"<--");


    var options = { method: 'GET',
  url: 'https://api.pipedrive.com/v1/deals/find',
  qs: 
   { term: user.data[0].name,
     api_token: '' },
  headers: 
   { 'postman-token': '',
     'cache-control': 'no-cache' } };

request(options, function (error, response, body) {
  if (error) throw new Error(error);

  var deal = JSON.parse(body);


var options = { method: 'PUT',
  url: 'https://api.pipedrive.com/v1/deals/'+deal.data[0].id,
  qs: { api_token: '' },
  headers: 
   { 'postman-token': '',
     'cache-control': 'no-cache',
     'content-type': 'application/json' },
  body: { stage_id: csvData[i-1][9]},
  json: true };

request(options, function (error, response, body) {
  if (error) throw new Error(error);

});

});


});


}


});

Firstly you have a syntax error. Please fix that first. – Aron Jul 24 '17 at 12:32 — Aron, Jul 24 '17 at 12:32

score 1 · Answer 1 · answered Jul 24 '17 at 13:07

1

You need to use : -

async.eachOfSeries(coll, iteratee, callback) as parent loop and

async.eachSeries() as a child loop.

for more details see async library :

https://caolan.github.io/async/docs.html#eachOfSeries

answered Jul 24 '17 at 13:07

Krishan Kant Sharma

363
3
12

score 0 · Answer 2 · answered Jul 24 '17 at 12:36

0

You need to use closures How do JavaScript closures work?. You cannot guarantee values when it comes to async.

answered Jul 24 '17 at 12:36

kawadhiya21

2,458
21
34

can you tell how closures can do so? .I don't think closures can do so. – Himanshu sharma Jul 24 '17 at 12:42

score 0 · Answer 3 · answered Jul 24 '17 at 12:45

Use the series method of the Async library.

async.series(['mail', '20.03.2017 05:32', '11.07.2017 03:44', '2', '0', '2', '0', '4', '3', '46' ].map( elem => { 
  return done => { // Building an array of functions to pass to Async. They will be executed one after the other, when done() is called
       callYourApi( elem, result => done(null,result) ) // 1st argument = error, null == no error
  }
},
(err, results) => { // Global callback when all the calls are finished (or when an error occured in the chain)
  // results is now an array of all the "result" of every call
})

score 0 · Answer 4 · answered Jul 24 '17 at 12:49

Buddy .

firstly the syntax you are doing is wrong.

IF you want 1 request than 2 request than 3 request

you have to do like this

request(options1,function(){

request(options2,function(){
  request(options3,function(){
      // callback here
      });
});


});

and apply async or promises instead of for loop.

check async or promise in node.

Node.js for loop with http requests

4 Answers4