Http Get Request in Node.Js Express

HTTP GET Request in Node.js Express

Here is a snippet of some code from a sample of mine. It's asynchronous and returns a JSON object. It can do any form of GET request.

Note that there are more optimal ways (just a sample) - for example, instead of concatenating the chunks you put into an array and join it etc... Hopefully, it gets you started in the right direction:

const http = require('http');
const https = require('https');

/**
 * getJSON:  RESTful GET request returning JSON object(s)
 * @param options: http options object
 * @param callback: callback to pass the results JSON object(s) back
 */

module.exports.getJSON = (options, onResult) => {
  console.log('rest::getJSON');
  const port = options.port == 443 ? https : http;

  let output = '';

  const req = port.request(options, (res) => {
    console.log(`${options.host} : ${res.statusCode}`);
    res.setEncoding('utf8');

    res.on('data', (chunk) => {
      output += chunk;
    });

    res.on('end', () => {
      let obj = JSON.parse(output);

      onResult(res.statusCode, obj);
    });
  });

  req.on('error', (err) => {
    // res.send('error: ' + err.message);
  });

  req.end();
};

It's called by creating an options object like:

const options = {
  host: 'somesite.com',
  port: 443,
  path: '/some/path',
  method: 'GET',
  headers: {
    'Content-Type': 'application/json'
  }
};

And providing a callback function.

For example, in a service, I require the REST module above and then do this:

rest.getJSON(options, (statusCode, result) => {
  // I could work with the resulting HTML/JSON here. I could also just return it
  console.log(`onResult: (${statusCode})\n\n${JSON.stringify(result)}`);

  res.statusCode = statusCode;

  res.send(result);
});

UPDATE

If you're looking for async/await (linear, no callback), promises, compile time support and intellisense, we created a lightweight HTTP and REST client that fits that bill:

Microsoft typed-rest-client

Nodejs + Express: How to get an element which made an HTTP GET request?

You need to pass the information about the row/item that makes the GET request, that is a must.

Now with Express there are a couple of ways to do this: Express routing.

1. Defining route params: req.params

GET Request: /documents/table/file/345 (345 is the row identifier name or id etc)

At nodejs express end:

router.get("/documents/table/file/:id", (req, res) => {
  /*request parameter with this kind of route sits in req.params*/
  console.log(req.params);
  const requestedId = req.params.id;
});

2. Sending as query string parameters: req.query

GET Request: /documents/table/file?id=345

At nodejs express end:

router.get("/documents/table/file/", (req, res) => {
  /*request parameter with this kind of route sits in req.query*/
  console.log(req.query);
  const requestedId = req.query.id;
});

Making external get request with Express

The accepted answer is good, but in case anyone comes across this question later, let's keep in mind that as of February, 2020, request is now deprecated.

So what can we do? We can use another library. I would suggest Axios.

Install it and do something like:

const axios = require('axios')

const url = "https://example.com"

const getData = async (url) => {
  try {
    const response = await axios.get(url)
    const data = response.data
    console.log(data)
  } catch (error) {
    console.log(error)
  }
}

getData(url)

NodeJS express make get request

If you want simple requests, don't use the express module, but for example request :

var request = require('request');
request('http://www.google.com', function (error, response, body) {
  if (!error && response.statusCode == 200) {
    console.log(body) // Print the google web page.
  }
})

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