Category: JavaScript Answers

Sometimes, we want to get the response body with Node.js http.get.

In this article, we’ll look at how to get the response body with Node.js http.get.

How to get the response body with Node.js http.get?

To get the response body with Node.js http.get, we can get it from the callback we pass into http.request.

For instance, we write

const options = {
  host: 'www.example.com',
  port: 80,
  path: '/upload',
  method: 'POST'
};

const req = http.request(options, (res) => {
  console.log('STATUS: ' + res.statusCode);
  console.log('HEADERS: ' + JSON.stringify(res.headers));
  res.setEncoding('utf8');
  res.on('data', (chunk) => {
    console.log('body: ' + chunk);
  });
});

req.on('error', (e) => {
  console.log('problem with request: ' + e.message);
});

req.write('data\n');
req.write('data\n');
req.end();

to call http.request with the options object and a callback that has the res parameter.

In it, we call res.on with 'data' to listen to the data event which has the response data set as the value of chunk.

The data event is emitted when response data is received.

The response headers are in res.headers.

The response status code is in res.statusCode.

When there’s an error with the request, the 'error' event handler runs.

We listen for them with

req.on('error', (e) => {
  console.log('problem with request: ' + e.message);
});

And we call req.write to write data to the request body.

Finally, we close the handle with req.end.

Conclusion

To get the response body with Node.js http.get, we can get it from the callback we pass into http.request.

Sometimes, we want to make a HTTP GET request in Node.js Express.

In this article, we’ll look at how to make a HTTP GET request in Node.js Express.

How to make a HTTP GET request in Node.js Express?

To make a HTTP GET request in Node.js Express, we can use the axios.get method.

For instance, we write

const axios = require('axios');

const f = async () => {
  const {
    data
  } = await axios.get('https://example.com')
}

to call axios.get with the URL we want to make the GET request to.

axios.get returns a promise that resolves to the response.

Then we get the response data from the data property returned by the promise.

Conclusion

To make a HTTP GET request in Node.js Express, we can use the axios.get method.

Sometimes, we want to convert string to ObjectId with Node.js Mongoose.

In this article, we’ll look at how to convert string to ObjectId with Node.js Mongoose.

How to convert string to ObjectId with Node.js Mongoose?

To convert string to ObjectId with Node.js Mongoose, we can use the mongoose.Types.ObjectId method.

For instance, we write

const mongoose = require('mongoose');
const id = mongoose.Types.ObjectId('4edd40c86762e0fb12000003');

to call mongoose.Types.ObjectId with the ObjectId string to convert the string to an ObjectId.

Conclusion

To convert string to ObjectId with Node.js Mongoose, we can use the mongoose.Types.ObjectId method.

Sometimes, we want to replace a string in a file with Node.js.

In this article, we’ll look at how to replace a string in a file with Node.js.

How to replace a string in a file with Node.js?

To replace a string in a file with Node.js, we can use the readFile and writeFile method.

For instance, we write

const fs = require('fs')

fs.readFile(someFile, 'utf8', (err, data) => {
  if (err) {
    return console.log(err);
  }
  const result = data.replace(/string to be replaced/g, 'replacement');

  fs.writeFile(someFile, result, 'utf8', (err) => {
    if (err) {
      return console.log(err);
    }
  });
});

to call fs.readFile at path someFile.

And we read it as 'utf8 encoded file.

In the callback we pass into readFile, we get the read file content from data.

Then we call data.replace with a regex that matches the text we want to replace and replace them with 'replacement'.

Next, we call fs.writeFile to write the new result to path someFile.

Conclusion

To replace a string in a file with Node.js, we can use the readFile and writeFile method.

Sometimes, we want to read a file in Node.js.

In this article, we’ll look at how to read a file in Node.js.

How to read a file in Node.js?

To read a file in Node.js, we can use the fs.readFile method.

For instance, we write

const fs = require('fs')
const path = require('path')
const filePath = path.join(__dirname, 'start.html');

fs.readFile(filePath, {
  encoding: 'utf-8'
}, (err, data) => {
  if (!err) {
    console.log(data);
  } else {
    console.log(err);
  }
});

to call fs.readFile with the path of the file to read, an object with encoding to read the file with the given encoding, and a callback that has the read file data when the file is read.

We read the file at filePath as a text file encoded with 'utf-8'.

And then we get the file data from data.

If err is set, that means there’s an error when reading the file.

Conclusion

To read a file in Node.js, we can use the fs.readFile method.