An Intro to ExpressJS
An Intro to ExpressJS
An Intro to ExpressJS
An Intro to ExpressJS

What is ExpressJS, Why should you learn it, where is it used? - Find out answers to all the questions you may have about ExpressJS in this blog.


What is ExpressJS?

Express is a minimalist web framework. It's a layer built on top of the NodeJS and provides you with a robust set of features that make it easy to manage servers and routes. It essentially acts as a series of middleware function calls, each of which performs a specific function. Express is not opinionated, which is why you can use it in various ways. It does not, for example, impose a specific design pattern or folder structure.

Since 2016, the open-source Express project has been managed by the NodeJS Foundation. In recent years, Express has shown a high rate of adoption, with many small-scale companies opting to use the framework. Moreover, many other web frameworks, including Kraken, LoopBack, Keystone, and Sails, also use it.

ExpressJS History

TJ Holowaychuk was the original author and founder of ExpressJS. According to ExpressJS's GitHub repository, the first release occurred on May 22, 2010. Version 0.12 is available.

In June 2014, StrongLoop acquired the rights to manage the project. Then in September 2015, IBM acquired StrongLoop; and later, in January 2016, IBM announced that it would place ExpressJS under the control of the NodeJS Foundation incubator.

Why ExpressJS?

ExpressJS is a minimal framework that supports JavaScript, a widely used language that is simple to learn and is widely supported. This minimalist web framework provides robust set of features that makes it simple to create various types of web and mobile applications in a short amount of time. ExpressJS comes built in with an Express router that provides a simple route handler for client requests. It also includes a middleware responsible for making decisions to respond correctly to the client's requests.

Without Express JS, you must write your own code to create a routing component, which is time-consuming and labor-intensive. ExpressJS provides programmers with simplicity, flexibility, efficiency, minimalism, and scalability. Moreover, because it is a Node.JS web application framework, it also offers the advantage of high performance.

Express JS performs all executions extremely quickly thanks to the Event Loop, which eliminates any inefficiency. In addition, Express JS's powerful performance and ease of coding are the most popular features among web application developers. Because it is written in Javascript, it can be used to create websites, web and mobile applications, and even mobile apps.

Here are some more reasons why developers around the world love ExpressJS:

  • Express JS was designed to make it simple to create APIs and web applications.
  • It cuts coding time in half while still producing web content.
  • Mobile applications are more efficient.
  • Another reason to use Express is that it is written in JavaScript, a simple language, even if you have no prior knowledge of any language. Express JS enables a large number of new developers to enter the field of web development.

What Does an ExpressJS Developer Do?

A JS Express developer is a software specialist who works with Node, an open-source developer tool that runs on the server-side functionality of a website. They are mainly in charge of developing and maintaining network applications.

They are also responsible for managing the data exchanged between servers and users. In addition, they develop most of the backend components and connect applications to third-party web services.

They do not always work alone. ExpressJS developers work alongside front-end developers to integrate web-based applications. Their role may be determined by the business needs of a project or the company.

The following are the typical roles and responsibilities of an ExpressJS developer within a development team:

  • Write minimal code that is clean, efficient, reusable and containing appropriate comments section.
  • Create and maintain server-side components.
  • Create and implement high-performance applications.
  • Integrate server-side logic into front-end developer-created user-facing components.
  • Include data security, content negotiation, and cybersecurity measures.
  • Ensure that the main database and a front-end HTTP port request are performing optimally.
  • Determine and put in place data storage solutions.
  • Perform diagnostic tests, bug fixes, and user technical support.
  • Prepare project reports and document software development processes.
  • Make suggestions for improvement and incorporate them into daily tasks and processes.

How to Become an ExpressJS Developer

Learn the Basics

To become an ExpressJS developer, you should have some prior knowledge of web environments and programming languages such as HTML5 and CSS, as well as an understanding of how the various code components interact. Unfortunately, Express is not formally taught in traditional higher education because it is open-source software. As a result, you should pursue self-study via online courses.

Experience with Express and Other Frameworks

One of the many reasons ExpressJS is so popular is the availability of numerous frameworks and libraries that provide extremely powerful tools for developing highly scalable, feature-rich software applications. In addition, several businesses rely on these frameworks and libraries to develop their applications. As a result, they are in high demand on the market.

Knowing how to work with modern frameworks and libraries is an essential ExpressJS developer skill. Although you can create your const port servers and HTTP request methods and modules, it is more convenient and faster to build on a reliable web application framework because it is more secure and speeds up ExpressJS application development.

However, numerous Node.JS web application frameworks are available, including Mevn Stack, ExpressJS, MeteorJS, and Adonis.JS, to name a few. As a result, selecting the best JS web application framework for your development is critical. ExpressJS is extremely popular and serves as the "de facto" web application framework that all developers are expected to be familiar with. So start with single page applications and work your way up.

Understanding of Middlewares

The ExpressJS framework provides numerous features for developing server-side applications. Middleware is a required component of any Express NodeJS web application. Middleware, as the name implies, occurs somewhere in the middle and is used in many languages and tools, including Express as Middleware Express. It facilitates communication between two entities by acting as a bridge.

Middleware functions in an application's request-response cycle access the request object (req), the response object (res), and any other middleware function that should be called next. These req and res objects can be modified by Middleware functions for tasks such as handling request bodies, modifying response headers, and so on.

Assume you want to use an API to add products to your backend database. By validating the user's details, you can create a middleware that checks if the user attempting to perform this action has the proper credentials. As a result, understanding Middlewares will enable you to write more robust and dependable ExpressJS applications.

Version Control Tools and Package management

Every ExpressJS developer should be familiar with source control tools such as git and Github to work collaboratively with other team members. These tools offer collaborative code tracking and iteration features that are useful when working on complex projects, allowing you to track and make source code changes while resolving conflicts in the codebase.

Furthermore, package management is an important part of the ExpressJS community. Fortunately, ExpressJS includes the NPM CLI, a command-line interface that allows software developers to easily share libraries and manage dependencies. Because you'll be working with packages all the time as an ExpressJS developer, you should be familiar with them.

Database Management and Template engines

Creating an ExpressJS application with HTTP methods support necessitates understanding how to store dynamic data in a persistence layer, such as a database. As the complexity of your application grows, so does data interaction.

Working with businesses or applications that deal with large amounts of data necessitates a solid understanding of HTTP and database management. You should be able to define table schemas, update records, integrate multiple databases if necessary, and ensure database security as an ExpressJS developer.

Make security a priority.

Web security has always been a concern, but the recent increase in cyber-attacks and breaches is now more critical than ever. As a result, data protection is now expected of any production application that users entrust with sensitive information. As a result, some data protection techniques must be applied to ExpressJS HTTP programs and web apps to maintain the application's security.

As an ExpressJS developer, you must understand how to provide secure authentication in your web application and efficiently encrypt sensitive data in ExpressJS. In addition, you should be familiar with dependency audits to identify and resolve potential security issues in your dependencies.

Advantages of ExpressJS

Free and open-source 

Express is free and open-source under the MIT license, so you won't have to spend any money on it. This allows you to save money on tooling. Furthermore, most frameworks are no longer free.

Because this is open-source software, developers worldwide collaborate to make it better and more powerful. SaaS Boilerplate, Builder Book, and BitMidi are some of the most popular open-source projects built on the express framework.

Great Performance for Web and Mobile Applications

One of the most impressive features of Express is that it allows you to create high-performance web applications, which improves the user experience. User experience is critical to retention and repeat purchases, as most entrepreneurs and technology leaders understand.

Express is a minimalist framework that provides a thin layer of basic web app features and includes expert-written code. As a result, when you use Express in your project, you are using high-quality code that results in an excellent performance.

You can always improve your web app's performance by optimizing your code and resources. Image optimization for the web is one of the most effective ways to improve the speed and responsiveness of your website.

Minimalist web framework

Express makes it simple to write code while providing the performance of NodeJS. This framework includes useful tools and features that make life much easier. The ease of use is critical and if the development tool is difficult to use, the developer will have to waste a lot of time figuring out how to use it properly, which ExpressJS avoids.

Creating APIs is easy with Express.

Another great reason to use Express is that it makes it simple to create APIs. This enables backend developers, particularly those new to JavaScript, to ramp up quickly.

Rapid development

One of the reasons people use web frameworks is to build their apps more quickly. Using frameworks simplifies and speeds up the development process. You don't have to write code from scratch for every feature you want to develop using a modern framework like Express.

Express provides pre-built functions, libraries, and tools that help to accelerate the web development process. This tool's frameworks, such as Feathers, Poet, LoopBack, and Kites, can help you quickly complete many mundane development tasks.

Express also allows you to create your middleware functions, which can reduce the number of lines of code required, saving you time and effort. This framework also includes a set of pre-built middleware functions for quick app development. In addition, you can use third-party middleware functions to easily extend the functionalities of your Express app to build things even faster.

Modern JS web application framework

Express is a popular and modern web app development framework that includes all of the latest features and capabilities. It makes it simple to create modern, powerful applications.

Because Express is a newer technology than Laravel and others, creating a modern, responsive app with this framework is easier. In addition, Express is a NodeJS framework, and because NodeJS is a modern technology, Express can produce high-quality, stable web apps.

Strong community support

Express has strong community support from members working hard to improve the framework. It currently has 261 contributors on its GitHub page. Furthermore, many people have effectively assisted aspiring Express developers in learning the framework by producing high-quality blog posts, tutorials, and answers to Express-related questions.

How to Install ExpressJS?

Before using the Express framework, you'll need to install it in your project directory. This is a straightforward process that requires NodeJS and npm.

The Node Package Manager is used to install Express. This is done by entering the following command into the CLI:

npm install Express

This requests the Node package manager to download the required express modules and install them accordingly.

Components of ExpressJS

The JavaScript runtime in the browser contains an implementation of JavaScript that allows developers to create web applications. The web browser's runtime includes three critical components:

  • The Core: The JavaScript base implementation includes all the input and output functions that developers can use.
  • Document Object Model (DOM): For XML and HTML, this is what the browser renders as a hierarchy of nodes to be displayed to the client or user. The Document Object Model is a language-independent interface for XML and HTML that maps out the entire document as a tree-like hierarchy of nodes. The HTML code snippet below is an excellent example of a node hierarchy:
    <!DOCTYPE html>
    <html>
      <body>
        <h1>Hello World</h1>
        <p>My first paragraph.</p>
      </body>
    </html>
  • Browser Object Model (BOM): This is how developers can manipulate the browser window. Using the BOM, developers can access and manipulate browser features outside of the context of the DOM or the page being rendered.

Development Best Practices

Use gzip compression

Gzip compression can significantly reduce the size of the response body, increasing the speed of a web app. Use the compression middleware to compress data with gzip in your Express app. Here is an example that uses gzip compression:

const compression = require('compression')
const express = require('express')
const app = express()
app.use(compression())

The best way to implement compression on a high-traffic website in production is at the reverse proxy level (see Use a reverse proxy).

Don't use synchronous functions

Synchronous functions and methods prevent the executing process from continuing until they return. A single call to a synchronous function may return in a few microseconds or milliseconds, but on busy websites, these calls accumulate and reduce app performance. So avoid using them in production.

Although Node and many modules provide both synchronous and asynchronous versions of their methods, the asynchronous version should be utilized in production at all times. This is because a synchronous function can only be justified on startup.

Do logging correctly

There are two reasons to implement logging for your app: debugging and activity logging (essentially, everything else). It is common development practice to use either console.log() or console.error() to print the log messages to the terminal. However, because these functions are synchronous when the destination is a terminal or a file, they are not suitable for production use unless the output is piped to another program.

For debugging

If you're logging for debugging purposes, use a special debugging module like debug instead of console.log(). This module lets you use the DEBUG environment variable to control which debug messages, if any, are sent to console.error().

For app activity

Instead of using console.log() to log app activity (such as tracking traffic or API calls), use a logging library such as Winston or Bunyan.

Handle exceptions properly

When an uncaught exception occurs, Node apps crash. If you do not handle exceptions and take appropriate actions, your Express app will crash and go offline. However, if you follow the instructions in the section Ensure your app automatically restarts, your app will recover from a crash. On the other hand, Express apps typically have a quick startup time. However, if you want to avoid crashing in the first place and to do so, you must properly handle exceptions.

Use the following techniques to ensure you handle all exceptions:

  • Use try-catch
  • Use promises

The callback function must follow the error-first callback convention to handle the error appropriately. The next() function is the easiest way to propagate problems down the middleware chain in Express.

Promises will handle any explicit or implicit exceptions in asynchronous code blocks that use then(). Simply include .catch(next) at the end of the promise chains. Here is an example that uses promises:

app.get('/', (req, res, next) => {
  // do some sync stuff
  queryDb()
    .then((data) => makeCsv(data)) // handle data
    .then((csv) => { /* handle csv */ })
    .catch(next)
})

app.use((err, req, res, next) => {
  // handle error
})

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