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);
});
});
});
}
});

• Aron: Firstly you have a syntax error. Please fix that first.

Answer 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

Answer 2

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

• Himanshu sharma: can you tell how closures can do so? .I don't think closures can do so.

Answer 3

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
})

Answer 4

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.