I am a rookie in Nodejs and asynchronous programming. I am having a problem executing a GET Request inside an asynchronous function. Here I am posting the whole code. I am trying to pull a list of all Urls , add them to a list and send the list for processing to another function.

My problem is with processing them. Inturn for each url I am executing a GET request to fetch the body and to look for image elements in it. I am looking to pass the Image url to a 3rd party api as a GET param. I am unable to execute the GET request as the control doesn't seem to reach there at all.

var async = require("async"),
request = require("request"),
cheerio = require("cheerio");


async.waterfall([

function(callback) {
    var url = "someSourceUrl";
    var linkList = [];
    request(url, function(err, resp, body) {
        var $ = cheerio.load(body);
        $('.list_more li').each(function() {
            //Find all urls and add them to a list
            $(this).find('a').each(function() {
                linkList.push($(this).attr('href'));
            });
        });
        callback(null, linkList);
    });
},


//pass all the links as a list to callback
function(liksListFetched, callback) {
    for (var i in liksListFetched) {
        callback(null, liksListFetched[i]);
    }
}],

//***********My problem is with the below code**************
function(err, curUrl) {
    var cuResp = "";
    console.log("Currently Processing Url : " + curUrl);

    request(curUrl, function(err, resp, body) {

        var $ = cheerio.load(body);
        var article = $("article");
        var articleImage = article.find("figure").children('img').attr('src');
        var responseGrabbed = "API response : ";
        //check if there is an IMG element
        if (articleImage === undefined) {
            console.log("No Image Found.");
            articleImage = 'none';
        }
        else {
            //if there is an img element, pass this image url to an API,
            //So do a GET call by passing imageUrl to the API as a GET param
            request("http://apiurl.tld?imageurl=" + articleImage, function(error, response, resp) {             //code doesn't seem to reach here 
                I would like to grab the response and concatenate it to the responseGrabbed var.
                console.log(resp);
                responseGrabbed += resp;
            });
        }
        console.log(responseGrabbed);// api response never gets concatenated :(
        console.log("_=_=_=_=_=_=__=_=_=_=_=_=__=_=_=_=_=_=__=_=_=_=_=_=_");
        process.exit(0);
    });
});

I appreciate if any one can help me understand the root cause. Thanks in advance.

request() is asynchronous, so when you're console logging the string, the string hasn't been built yet, you have to do the console log inside the callback :

request("http://apiurl.tld?imageurl=" + articleImage, function(error, response, resp) {                             
    responseGrabbed += resp;
    console.log(responseGrabbed);// api response never gets concatenated :(
    console.log("_=_=_=_=_=_=__=_=_=_=_=_=__=_=_=_=_=_=__=_=_=_=_=_=_");
});

Same goes for terminating the process, which should be done when all the requests have finished