CODEWITHSUNDEEP
javascriptnode.js
Trewaters
Trewaters

Reputation: 1079

What does response.on mean? Node.js

I am having trouble with a Node.js http request. (A bigger question I will ask about later if I can't figure it out).

I have code that I modified from and an example and I don't understand what the response.on means. As read more about http in Node.js (Anatomy of an HTTP Transaction) I don't see people using examples with 'response.on'. I think I know but I want to clarify. Oh I am using Express.js too.

Thanks

Below is the code I am using to try and call the BART api I need a response from.

...
// Real Time Departure from a given station
router.route('/departTimeStation')
.get(function(req, res) {
    vCmd = 'etd';
    vOrig = req.query.vOriginStation;
    vDir = 'n'; // [NOTE] - 'n' or 's', north or south, OPTIONAL
    vPlat = 1; // [NOTE] - 1 to 4, number of platform, OPTIONAL

    var xoptions = {
        host: 'api.bart.gov',
        path: '/api/etd.aspx?cmd=' + vCmd + '&orig=' + vOrig + '&key=' + config.bart.client
    };

    var xcallback = function(response) {

        response.on('data', function(chunk) {
            vParsed += chunk;
        });

        response.on('end', function() {
            parseString(vParsed, function(err, result) {
                vShow = JSON.stringify(result);
                vTemp = result;
            });
        });
    };
    http.request(xoptions, xcallback).end();
    return res.send (vTemp)
});
...

Upvotes: 4

Views: 19153

Answers (2)

Boy Code It
Boy Code It

Reputation: 1

response.on is a function, or rather method, since it is a property.

Upvotes: -5

omarjmh
omarjmh

Reputation: 13896

response.on can take a few 'events' that happen during the response life cycle,

The two you have above are response.on('data'...) which is when you get the data and response.on('end'...) is at the end of the response, simple as that!

Node Docs on response: https://nodejs.org/api/http.html#http_class_http_incomingmessage

Upvotes: 6

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