Node.js Stream readable.setEncoding() Method

In this article, we will discuss the Node.js Stream readable.setencoding() method with their syntax, parameters, and examples.

What is the Node.js Stream readable.setEncoding() method?

The method "readable.setencoding()" sets the encoding type for a file. In node.js, it is used to read the "Readable" stream. While reading data from a file, the character encoding is applied to the data present in the file. This method is used mainly for text files.

Syntax:

It has the following syntax:

Here the encoding is the string, which represents the type of the encoding. Some of the character encoding to use are "utf8", "ascii", and "base64". etc.

Advantages of using this method

• It simplifies text processing by automatically converting the buffer objects to strings.
• It is often used in string manipulation and string processing.
• The data received from the stream are consistent after encoding into desired encoding type.

General applications where this method is used:

• File reading
• Processing responses from HTTP
• While reading input from the command line
• It is used in network sockets and communication protocols where text is involved.

Example 1:

Let us take an example to illustrate the setEncoding method in Node.js:

Example.txt file

Output:

Explanation:

The above program opens the example.txt file, reads the file, encodes the data into the "base64" encoding type, and displays the data in the console.

Example 2:

Let us take a simple node.js application to illustrate the setEncoding method:

Index.html

Server.js file

Console output:

Application interfaces

Steps to create and run this application:

1. First, create a folder named application.
2. Go to the application directory.
3. After that, use the command "npm init" to create a new package.json file for the project.
4. Next, install necessary packages like express and body parser using the command "npm install express body-parser".
5. After that, create an html file and name it "index.html" and paste the above html code.
6. Now, create a JavaScript file and name is "server.js" and paste the above server.js code.
7. Next, we can use the command "node server.js" to run the application.
8. Now, in browser go to http://localhost:3000 where we can see the application and interact with the website.

Explanation for html code:

This html file represents a simple web application called "Text Encoder". This page contains one "textarea" field, options to select the encoding type and a submit button. Here, the user will give some text as input for the textarea field, and the user will select the encoding type. When the user clicks on the submit button, the output is shown after encoding.

When the input form is submitted, it prevents the default submission behavior of the form, but it sends the input data to the server endpoint "/encode" using a POST request. There is some JavaScript code in the script section of the HTML page that handles the form submission. The input data is sent to the server after getting the response from the server. That response is the encoded form of the input that will be displayed on the web page. There is the style section where different styling properties are used to style the html page.

Explanation for JavaScript code:

The script imports the required modules like express, body-parser, fs, and path. After that, an express application instance is created, a body-parser is used as middleware for the application, and GET and POST routes are defined. The GET route for the URL "/" will serve the "index.html" file, and the POST route for the URL "/encode". The POST request extracts the text and encoding type from the request body. After that, it writes the data to some file and, after using the readable stream, is specified with the "encoding" method for some encoding type. Now, the encoding data is concatenated to the data variable. This data is sent back as a response. The server is listening on port 3000.