How to loop arrays with node.js request()

Question

I went from passing single values into my node API to passing multiple values and the API stopped sending a response back.

Example of single values for fields:

tracking: "123", // Only one tracking number
carrier: "usps" // Only one carrier code

Example of multiple values for fields:

tracking: [ '9361289691090998780363', '784644233417' ],
carrier: [ 'usps', 'fedex' ]

I think I need to add some sort of loop but I cant figure out how to do this nor do I know what the proper terminology is to look this up. Is this related to aync? I'm lost.

request(options, function (error, response, body){});

Here is my code. Any help / additional information would be grateful in understanding what I am doing wrong.

html.js

// These are sent over in an AJAX call //
var trackingNumber = ['9361289691090998780363', '784644233417'];
var carrierCode = ['usps', 'fedex'];

controller.js

app.get("/api/tracking/retrieve", (req, res) => {

    var carrier = req.query.carrier;
    var tracking = req.query.tracking;

    console.log('carrier array', carrier);
    console.log('tracking array', tracking);

    var options = {
        method: "GET",
        url: 'https://api.example.com/v1/tracking',
        qs: { carrier_code: carrier, tracking_number: tracking },
        headers:
            {
                'api-key': process.env.SECRET_KEY_SE,
                'accept': 'application/json'
            }
    }

    console.log("Url: ", req.url);
    console.log("Query: ", req.query);
    // res.send("ok");

    request(options, function (error, response, body) {
        if (!error && response.statusCode == 200) {
            console.log('BODY', body)

            var trackingData = JSON.parse(body)
            console.log('trackingData: ', trackingData);
            table = 'tracking_table';
            col = [
                'user_id',
                'tracking_number',
                'carrier_code',
            ];

            val = [
                user_id,
                trackingData.tracking_number,
                options.qs.carrier_code,
            ];

            main.create(table, col, val, function (data) {
                res.json({
                    id: data.insertId,
                    user_id: user_id,
                    tracking_number: data.tracking_number,
                    carrier_code: data.carrier_code,
                });
            })
        }
    })

})

Answer 1

From your controller I can actually see that as soon as you get the request, you are sending the response back. How can you send response again?

I have commented your res.send('ok') and it works.

app.get("/api/tracking/retrieve", (req, res) => {
    var carrier = req.query.carrier;
    var tracking = req.query.tracking;
    console.log('carrier array', carrier);
    console.log('tracking array', tracking);
    var options = {
        method: "GET",
        url: 'https://api.example.com/v1/tracking',
        qs: { carrier_code: carrier, tracking_number: tracking },
        headers:
            {
                'api-key': process.env.SECRET_KEY_SE,
                'accept': 'application/json'
            }
    }
    console.log("Url: ", req.url);
    console.log("Query: ", req.query);
    // res.send("ok"); <--
    request(options, function (error, response, body) {
        if (!error && response.statusCode == 200) {
            console.log('BODY', body)
            var trackingData = JSON.parse(body)
            console.log('trackingData: ', trackingData);
            table = 'tracking_table';
            col = [
                'user_id',
                'tracking_number',
                'carrier_code',
            ];
            val = [
                user_id,
                trackingData.tracking_number,
                options.qs.carrier_code,
            ];
            main.create(table, col, val, function (data) {
                res.json({
                    id: data.insertId,
                    user_id: user_id,
                    tracking_number: data.tracking_number,
                    carrier_code: data.carrier_code,
                });
            })
        }
    })
});