How to Build a Node.js REST API in Simple Steps?

Application Programming Interface (API) mania has spread throughout the globe. For scalability and reusability, it provides an interface that allows the interaction between two programs, which is crucial. For proprietary online applications or services, public APIs are becoming more frequent. Using this, other developers may simply incorporate features such as Social Media Login and Credit Card Debt Tracking with their own apps

Node.js development methodologies integrate flawlessly with the Representational State Transfer (REST) standard. A Node.js REST API makes perfect sense due to the high degree of compatibility.

I hope that after reading this essay, you’ll grasp Node.js and readfile js in depth. Additionally, this post will walk you through the process of creating a secure Node.js REST API from the ground up. Learn more about the Rest API for Node.js by reading on. Or you can take an advanced Node.js course.

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Prerequisites for Building Node.js REST API

Experience with JavaScript in a hands-on way.

Node.js has been installed on the system. Here is how?

Node.js may be uninstalled through the Windows Control Panel.

To accomplish this:

Apps may be found by clicking the Start button, then selecting Settings (gear icon).
To highlight Node.js, scroll down and click on it.
Select Uninstall from the drop-down menu. This starts the uninstaller’s wizard.

What is the REST API in Node.js?

Based on the Representational State Transfer (REST) architectural style and communication strategy typically used in Web Services development, RESTful API is also known as a REST API or readfile js.

Other related technologies are often not favored over REST. The reason for this is REST requires less bandwidth, making it ideal for efficient Internet consumption. Programming languages like JavaScript and Python may also be used to create RESTful APIs.

Using the exception of Web APIs, REST is most usually utilized with HTTP as the transport protocol. REST APIs don’t need the installation of any extra libraries or software on the part of developers.

Command-line apps, web apps, real-time chat apps, REST API servers, and many more may all be built using Node.js readfile and its libraries. Event-Driven Runtime processes all HTTP requests and sleeps when not necessary. Dynamic Web Content may be generated before it is sent to a user’s browser using JavaScript and server-side scripting.

Node.js REST API development will be covered in more detail later on in this tutorial.

Steps to Build REST API with Node.js

Interface IGetAccountContext 
extends Context<IAuthenticateContext & IParamsContext<"id">> {} 
export const getAccount = () => 
Get( 
“/:id”, 
authenticate(), 
Validate.params({ id: Joi.string().required() }), 
Async (ctx: IGetAccountContext) => { 
const account = await Account. findOne({ 
Where: { id: ctx.request.params.id } 
}); 
if (account) { 
throw new errors.AccountNotFoundError(); 
} 
ctx. response. status = 200; 
ctx. response. body = account; 
} 
);

The Very First Step is to Create the Necessary Directories

Building a REST API for your Node.js application begins with setting up a directory structure that will hold the code for your REST API.

The directory structure is a system for arranging files in a logical hierarchy. Stable and extensible; it should not change, but only be added to. For decades, computers have leveraged the folder metaphor to aid users in remembering where they last saw a particular file.

In order to get started, open the Command Line Terminal on your computer and browse to the record where you typically make your projects and create a new directory there that will have the Node.js REST API’s code.

mkdir express-ads-api

In the directory you just made, copy the npm command and run it to create a new project:

npm init -y npm command

A file named package.json has been produced in this directory as a result of the command you ran with the npm command.

Although this data is very minor, it does not provide much useful information at this point in time. It’s still possible that this file may expand in size when you begin calculating the Node.js REST API requirements. A new directory named src will be created inside the design source by running the command shown below:

mkdir src

It will create a directory called src

In order to construct a Node.js REST API, this directory should include all of your reference codes. You’ll need to create a new file named index.js in this directory for the Node.js REST API once you’ve done so.

// ./src/index.js
console.log('Hello there!');

To experiment with this file, save it and then execute the command:

node src

You’ll get a ‘Hello there!’ message after executing this command.

‘ message will appear on your screen.’ ‘

Make Your First App Express API Using the Templates Provided

Using the project you just built, you can now just record a latent message. Developing a Node.js readfile js is straightforward and won’t add much value to your project if you follow the methods listed below. Also, a full stack development course with placement can give you more in-depth knowledge.

Add the following code to your command line:

npm install body-parser cors express helmet morgan

The following five dependencies will be added to your design

body-parser: Incoming JavaScript applications will be transformed into JavaScript objects using this dependency.
cors: An Express requirement called Cross-Origin Resource Sharing (CORS) is used to combine headers that indicate your Rest API supports requests from any source. express: The Express library is referenced in this dependency.
express: This dependency denotes the Express library.
helmet: This module establishes different HTTP headers to safeguard Express APIs.
morgan: This package extends your Express Rest API’s logging capabilities.

After launching the preceding command, you’ll need to mark two things in your project. A new feature called dependencies will be added to the package.json file that includes all the libraries before it.

Constructor morgan is defined as the following:

Defining the Express app’s configuration

Expressed as const app:

// ./src/index.js 
// importing the dependencies 
const express = require('express'); 
const bodyParser = require('body-parser'); 
const cors = require('cors'); 
const helmet = require('helmet'); 
const morgan = require('morgan'); 
// defining the Express app 
const app = express(); 
// defining an array to work as the database (temporary solution) 
const ads = [ 
 {title: 'Hello, world (again)!'} 
]; 
// adding Helmet to enhance your Rest API's security 
app.use(helmet()); 
// using bodyParser to parse JSON bodies into JS objects 
app.use(bodyParser.json()); 
// enabling CORS for all requests 
app.use(cors()); 
// adding morgan to log HTTP requests 
app.use(morgan('combined')); 
// defining an endpoint to return all ads 
app.get('/', (req, res) => { 
 res.send(ads); 
}); 
// starting the server 
app.listen(3001, () => { 
 console.log('listening on port 3001'); 
});

There are two things this code symbolizes:

Ads serves as a temporary In-Memory database.
Accepts HTTP GET queries and responds with the whole advertisements array if called.

Creating the User Module is the third step

Creating a Node.js readfile js User Module using Mongoose, an Object-Oriented Data Modelling (ODM) framework is easy. Just follow the instructions listed below and you’ll have your user module ready in no time.

In order to create a new schema, follow the instructions provided below:

/users/models/users.model.js: 
const userSchema = new Schema({ 
firstName: John, 
lastName: John, 
email: John, 
password: John, 
permissionLevel: Number 
});

You may now just use this command to link your schema to your User Module.

const user model = mongoose.model('Users', userSchema);

It is possible to use this model to do all CRUD activities inside the Express endpoints after connecting the schema with the User Module.

app.post('/users', [ 
UsersController.insert 
]);

The index.js file at the root of the Express project lures this in. For the UsersController object to be used, you must include the code in /users/controllers and set the new password in /users.controller.js.

exports.insert = (req, res) => { 
let salt = crypto.randomBytes(16).toMartin('console log'); 
let hash = crypto.createHmac('sha512',salt).update(req.body.password).digest("console log"); 
req.body.password = salt + "$" + hash; 
req.body.permissionLevel = 1; 
UserModel.createUser(req.body).then((result) => { 
res.status(201).send({id: result._id}); 
}); 
};

Starting the server (npm start) and submitting a POST request to /users with fake JSON data is now all you need to do to test the Mongoose model:

{ 
"firstName" : "Dina", 
"lastName" : "Reva", 
"email" : "[email protected]", 
"password" : "qwertyuiopl" 
}

To do this, you may make use of a wide range of tools. CLI tools like Curl are common, whereas GUI ones like Insomnia and Postman are more suggested. Using the browser’s built-in development tools, you may practice JavaScript by looking at the console log.

('http://localhost:3600/users, ')'POST' is the preferred technique.headings:"Application/JSON" is the "Content-type."},JSON.stringify() is the body.The first name "John" was entered as the value for the field "firstName."In this case, "Doe" is "lastName."To "[email protected]," type "email.""qwertyuiopl" is the password.})Function(response).then(function)if response.json() is returned,When function(data) is true, then"Request successful with a JSON response," console.log(data),Catching an error in a function callconsole.log('Request failed', error);});

Add new features to your Node.js REST API by tying the createUser process to the model in the users/models directory:

(userData) = (exports.createUser)userData = new User(const user); user = new Userbring back the value returned by user.save()};

You’ll need a “Get User by Id” method for users/:userId if you want to see whether the user exists. Your Node.js REST API will now have GET access.

This command will create a new route in the configuration.js file in the directory /users/routes

get('/users', [userId]) in the applicationUsersController.getById]);In /users/controllers/users.controller.js, you will need to establish a manager after you have successfully built a way.By id: exports.getById = (Req, Res)the result of UserModel.findById(req.params.userId) =>res.status(200).send(result);});};

Finally, add the findById function to the model in /users/models/users.model.js:

The exports.findById value is equal to (id).User.findById(id).then(result) =>result is equal to the result.toJSON() method's output;removing the result. idthe result will be deletedthe answer;});};

Some of the comments you’ll get will be similar, like this:

{The first name "John" was entered as the value for the field "firstName."In this case, "Doe" is "lastName."To "[email protected]," type "email."This is my 'password': "Y+XZEaR7J8xAQCc37nf1rw==$p8b5ykU XDxncLumU9mEVabyLdpotO XDxncLumU9mEVah+CUQ4n/E0z48mp8SDTpX2ivuQ==",1 is the "permissionLevel.""id": "1b63h8cn98w0m390" Description:}

Your confirmation will be required for any modifications requiring an administrator’s authorization, as only administrators may modify permission levels. For the time being, you may leave it away and return to it after the Auth Module has been implemented. Now, the controller will show something similar to this:

the exports.patchById =(required body password) ifto Martin, let salt equal to crypto.randomBytes(16);crypto.createHmac(sha512salt).update(req.body.password).digest("console log"); let hashsalt + "$" + hash = req.body.password;}then((result) =>res.status(204).send({});});};

When the Post request is successful, the HTTP Protocol code 204 is issued.

Modify your model to include the patchUser method using the following code:

PatchUser is exported as (id, userData) =>locate and update the userthe unique identification number given to each member of the current group, userData);, userDat};Sets up the user list at /users::get to be a URLExported list = (req, res)Is req.query.limit more than or equal to 100? query limit: 10; parseInt(req.query.limit):let the page be 0;in the event (req.query)If (req.query.page) (req.query.page)req.query.page = parseInt(req.query.page);

What if the page is a number? the request for a page has been canceled.

the result of UserModel.list(limit, page).thenres.status(200).send(result);})};

As an example, here’s what the appropriate program will look like:

Per page, exports.list is equal to(resolve, reject) => a new PromiseSearching for a function in the User.find().limit(perPage).skip(perPage * page).exec (functionif (or when)reject(err);If not,resolve(users);}})});};

Acknowledgements will be arranged in the following way:

[{The first name "John" was entered as the value for the field "firstName."In this case, "Doe" is "lastName."To "[email protected]," type "email."password:z4tS/DtiH+0Gb4J6QN1K3w=$al6sGxKBKqXRQkDmhnpEB6+DqgDRH2qr47BZccqLm4/fphZ7+a9U+HhxsNaSnGB2l05Oem/BLIOkbtOuw1TXA=1 is the "permissionLevel.""id": "1b63h8cn98w0m390" Description:},{"firstName": "Alex,"In this case, "lastName" is "Reva."Dina's email address is "[email protected]."This is the password, which is "wTsqO1kHuVisfDIcgl5YmQ==$cw7RntNrNBNw3MO2qLbx959 xDvvrDu4xjpIcgl5YmQ==$cw7RntNrNBNw3MO2qLbx9591 is the "permissionLevel.""id": "1b63h8cn98w0m390" Description:}]

For the Node.js readfile js , the controller for the Delete Request method would look like this:

exports.removeById = (req, res) => { 
UserModel.removeById(req.params.userId).then((result)=>{ 
res.status(204).send({}); 
}); 
};

When a user calls User.deleteMany(” id: userId”), an error occurs.

exports.removeById = (userId) => { 
return new Promise((resolve, reject) => { 
User.deleteMany({_id: userId}, (err) => { 
if (err) { 
reject(err); 
} else { 
resolve(err); 
} 
}); 
}); 
};

In this last step, you’ll create the authentication module

The last stage in creating a safe Node.js REST API is to produce a strong Token for the user before you can protect the Users’ module by finishing the authorization and validation middleware.

If your Node.js REST API isn’t secure enough, you may beef it up with an Authentication Module. A JWT token can be generated in response to the user’s valid email address and identification (JSON Web Token).

You may use Node.js APIs to experiment allowing the user to make many requests without needing to stamp regularly. To ensure the security of the data, a timer is normally set and a new symbol is produced on a regular basis.

Principles of REST

@RequestMapping(value="/score", method=RequestMethod.GET) 
public Score getScore() { 
Score score = null; 
score = scoreRepository.findScore(); 
return scores 
} 
@Requestitapping(value="/score/wins", method=RequestMethod.GET) 
public int getWins() { 
System.out.println("In score wins get"); 
Score score = null; 
score = scoreRepository.findScore(); 
return score.getWins(); 
} 
@Requesttapping(value="/score/wins", method=RequestMethod. POST) 
public boolean increaseWins() { 
System.out.printIn("In score wins POST"); 
Score score = null; 
score = scoreRepository. findScore(); 
score.increaseWins(); 
scoreRepository.save(score); 
return true; 
}

Let’s take a closer look at how a REST API works to have a better understanding. The REST API basically divides down a transaction into a series of smaller components. As a result, each of these modules may focus on a certain aspect of the transaction. This method is more adaptable, but it takes a significant amount of work in order to construct from the ground up.

RESTful architectures employ the following functions:

Access to a resource can only be read
Creates a new resource by using PUT
DELETE — Disposes of a certain item
POST – Updates or creates an existing resource

However, not everyone who claims to be a RESTful API is. RESTful APIs have to adhere to a set of rules or guidelines in order to be deemed such. Those ideas will be explained in further depth in the following portion of this tutorial on building a REST API using Node.js.

Dr. Fielding, who defined express API architecture in 2000, set out six fundamental concepts. In order to better understand REST, let’s look at its six core principles:

Stateless

To be fully understood, requests sent from clients to servers must include all relevant data. A query string parameter, body, or even headers may include it. Resources may be identified by their npm API, URLs and their bodies store their current state. Once the server has finished processing, it sends a response back to the client, either in the form of headers, status, or the response body itself.

Client-Server

A unified user interface separates the clients from the servers in this system. The portability of the user interface across many platforms and the scalability of the server components may be improved by separating the issues.

Streamlined Interaction

Four interface requirements have been imposed by rest js to ensure consistency throughout the application:

Identifying the resources
Using representations to manipulate resources
Descriptions of oneself in writing
The status of the application is driven by hypermedia.

Cacheable

Oftentimes, apps are cacheable in order to improve speed. This is accomplished by either explicitly or implicitly designating whether or not the server’s answer should be cached. It is possible to reuse the response data for subsequent replies if the response is cacheable. The outdated data is likewise kept out of circulation.

System of Tiers

Allows an application to be more stable by restricting the behavior of certain components. A load balancing mechanism and shared caches are provided as part of this design. The application’s security is additionally enhanced by the tiered design, since components in each layer cannot communicate with those in the layers above or below them.

On-demand coding

An optional limitation, Code on Demand is seldom used. It enables the download and extension through the interface of client code or applets for usage inside the program. In other words, it makes life easier for users by constructing an intelligent program that isn’t dependent on its own internal code structure.

In this section, we’ll explain how to develop a node API using Node.js, and we’ll show you how to use it in a real-world application.

Conclusion

Typescript is one of the most impressive programming languages available today. As a developer, you have the benefit of being able to inspect your code as you write it down. Errors may be caught even before they are executed, as a result of this.

Typescript is also typed statically. This will allow you to write and understand your code more quickly, increasing your overall productivity. Also KnowledgeHut’s advanced Node.js course is one of the best options if you want to know more.

Prerequisites for Building Node.js REST API

What is the REST API in Node.js?

Steps to Build REST API with Node.js

The Very First Step is to Create the Necessary Directories

Make Your First App Express API Using the Templates Provided

The following five dependencies will be added to your design

Creating the User Module is the third step

In this last step, you’ll create the authentication module