Node.JS make multiple POST requests untill response is empty - node.js

Question

I'm making a POST request to API that has limited number of characters in response. In order to get full response I need to make multiple POST requests and then append them all to one file. I'm not that familiar with asynchronous programming so I can't think of a solution for my problem. Here is snippet of my code:
var request = require('request');
var fs = require('fs');
var options = {//options for POST request body};
request(options, function (error, response, body) {
if (!error && response.statusCode == 200) {
fs.appendFileSync("./response.json", JSON.stringify(body), 'utf8');
var resp = JSON.parse(fs.readFileSync('./response.json', 'utf8'));
options.offset = resp.parameters.length; //this is length of my data so far, next request will have this number in it and response will be new data offseted by this number
}
});
And after this request I need to make another one untill body.length is zero. So I guess what I need is to call request function from its own callback. How do I achieve this? Thanks!

Answer 1

Like JM-AGMS said, wrap the request function call in another function to have the callback of one request trigger the next request.
A recursive solution would look somewhat like this:
var request = require('request');
var fs = require('fs');
var options = {/*options for POST request body*/};
function loop(options) {
request(options, function (error, response, body) {
if (!error && response.statusCode == 200) {
if (body.length !== 0) {
fs.appendFileSync("./response.json", JSON.stringify(body), 'utf8');
var resp = JSON.parse(fs.readFileSync('./response.json', 'utf8'));
loop({ ...options, offset: resp.parameters.length });
}
}
});
}