Javascript Function returning no object

Question

I'm learning how to do a crawler (using 'cheerio') for a personal project. The crawling itself is working fine, but somehow the object I'm constructing (eventDetails) is not being returned. You can see below that the object, declared at the function level, is properly populated withing the request, but not outside it. Can you please help? Thanks.

function crawlEventDetails(eventLink){
    var eventDetails = new Object();
    //console.log(eventLink);
    request(urlDomain + eventLink, function(err, response, html) {
        if(err){
            console.log(err);
        }
        else {
            var $ = cheerio.load(html);
            eventDetails.date = $('.detail.textsmall').eq(0).text();
            eventDetails.time = $('.detail.textsmall').eq(1).text();
            eventDetails.place = $('.detail.textsmall').eq(2).text();
            eventDetails.price = $('.detail.textsmall').eq(3).text();
            console.log(eventDetails); //OK!
        }
    });
    console.log(eventDetails); //empty!
    return eventDetails; // empty!
}

Take some time to understand callback functions. There are lot of resources available on net. — priyadarshi swain, Nov 25 '17 at 19:28
Yes, I had tried to use callbacks and/or study async/await without success. I'll do more research, thanks. — user3250118, Nov 25 '17 at 21:05

score 1 · Answer 1 · answered Nov 25 '17 at 19:24

You are returning the object before the async function can complete. Look at sending a handler instead. i.e.:

function crawlEventDetails(eventLink, handler){
    var eventDetails = new Object();
    //console.log(eventLink);
    request(urlDomain + eventLink, function(err, response, html) {
        if(err){
            console.log(err);
        }
        else {
            var $ = cheerio.load(html);
            eventDetails.date = $('.detail.textsmall').eq(0).text();
            eventDetails.time = $('.detail.textsmall').eq(1).text();
            eventDetails.place = $('.detail.textsmall').eq(2).text();
            eventDetails.price = $('.detail.textsmall').eq(3).text();
            console.log(eventDetails); //OK!

            handler(eventDetails); // Send aka "return" to handler
        }
    });
}

// call `crawlEventDetails()` function, and 
// send an anonymous function to handle the response
crawlEventDetails(something, function(details){
    console.log(details);
});

I tried this once, I'll let you know if I manage it do it work. Thanks. — user3250118, Nov 25 '17 at 21:11

Javascript Function returning no object

1 Answers1