UNDERSTANDING NODE.JS BY BUILDING COMMAND LINE APPS

In this tutorial, I’ll be showing how to build command line applications using Node.js.

JavaScript is very popular for building all kinds of applications, from frontend applications to backend and mobile applications. The language keeps evolving and now you can build command line applications or control hardware devices like drones with JavaScript.

Prerequisites

This tutorial assumes the following:

Node.js and NPM installed on your computer
Basic knowledge of JavaScript and Node.js

What we’ll be building

In this tutorial, we’ll be learning how to build simple command line application. We’ll be building a command line weather application using Node.js. With our command line weather application, we’ll be able to get the current weather in any city in the world. We’ll also be able to get a forecast for any specified city using a different command line parameters.

Getting started

Let’s start by setting up our project and installing dependencies:

    $ mkdir weatherCLI
    $ cd weatherCLI
    $ npm init -y

This will create an empty directory called weatherCLI that will hold all our project files. After our project directory has been created, we change the directory to the project directory and initialize our project. A package.json file will be created and now we can proceed to install our project dependencies:

    $ npm install commander node-fetch --save

Commander is a Node.js library that makes writing command line applications easy. We’ll be leveraging the library to build our command line application. node-fetch is also a light-weight module that allows us make requests to external services to fetch data. We’ll use it to fetch weather data from APIXU.

Obtaining API keys

To obtain our API keys, we need an account on APIXU. Once you’ve created an account, login to the dashboard to find your API key that looks like 4a8****3e``*e248ac1*****``04.

Building the command line app

First, let’s create our project files. Create a src directory, and within it, create two files:

    $ touch src/index.js src/commands.js

Once the files are created, we’ll go ahead to create our commands for the app by adding the code below inside src/commands.js:

    // src/commands.js

    const fetch = require("node-fetch");
    const APIXU_KEY = "<YOUR APIXU KEY>";

We import the node-fetch library, then we create an APIXU_KEY variable, which holds our API key.

Next, we’ll go ahead to create two functions: fetchNow() to fetch the current weather for any specified city and weatherForecast() to fetch the forecast of any specified city likewise:

    // src/commands.js

    const fetchNow = async (city) => {
      const response = await fetch(`https://api.apixu.com/v1/current.json?key=${APIXU_KEY}&q=${city}`);
      const data = await response.json();

      const now = {
        location: data.location.name,
        country: data.location.country,
        longitude: data.location.lon,
        latitude: data.location.lat,
        temparature: data.current.temp_c,
        condition: data.current.condition.text
      }

      console.log(now)
    };

The fetchNow function is an asynchronous function that will return a Promise. It takes the passed cityas a parameter in order to make the complete API request. The await operator can only be used inside an asynchronous function and it returns the fulfilled value of the Promise, or the value itself if it’s not a Promise.

The now object holds just the necessary information we need from the data returned from the API request. The same thing applies to the weatherForecast function:

    // src/commands.js

    const weatherForecast = async (city) => {
        const response = await fetch(`https://api.apixu.com/v1/forecast.json?key=${APIXU_KEY}&q=${city}`);

      const data = await response.json();

      console.log(data.forecast)
    };

After defining all functions, we need to export them so they can be used in our command line program:

    // src/commands.js

    module.exports = {
      fetchNow,
      weatherForecast
    };

Our main application file src/index.js will hold the main application logic. Add the code below inside src/index.js:

    // src/index.js

    const program = require('commander');
    const { fetchNow, weatherForecast } = require('./commands');

We import the commander library and also the defined functions from src/commands.js. After the dependencies have been imported, we’ll define our program parameters:

    // src/index.js

    program
      .version('0.0.1')
      .description('Command line Weather Application')

    program
      .command("now <city>")
      .alias('n')
      .description('see the current weather in the specified city')
      .action(city => fetchNow(city));

    program
      .command("forecast <city>")
      .alias('f')
      .description('see the weather forcast of a specified city')
      .action(city => weatherForecast(city));

Let’s go over what each piece of the code above does:

.version allows us define the current version of our command line application
.command defines how the parameter should be passed to the program with any extra arguments
.alias defines an alternative short form parameter that can be passed to the program instead of typing a longer one.
.description is the description of the alias
.action will call whatever function is passed to it. The action runs the functions and displays whatever is returned from the function. The action is also responsible for handling interactions with the user if the command line application is an interactive application.

In order to read all parameters and arguments passed to our program, we have to parse the inputs after the program command. Add the snippet below as the last line inside weatherCLI.js:

    // src/index.js

    program.parse(process.argv)

Running and testing the CLI application

To run and test our application, run the command below:

    $ node src/index.js now lagos

It will return the current weather in Lagos as in the image below:

To fetch the weather forecast for Lagos, run:

    $ node src/index.js f lagos

Also, we can run additional commands as below:

    $ node src/index.js --help

This will return the application usage menu.

    $ node src/index.js --version

This will return the application version as specified earlier in src/index.js.

Conclusion

From the tutorial, we can see how easy it is to create command line applications using the Node.js Commander library. We’ve been able to create a command line application that can display the current weather of any city in the world using the APIXU. You can work more on the display formats so the displayed data looks interesting to users and also add a network loader while the application is fetching the weather reports.

The complete code for this tutorial is available on GitHub.

#node-js

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UNDERSTANDING NODE.JS BY BUILDING COMMAND LINE APPS

Aria Barnes

1622719015

Why use Node.js for Web Development? Benefits and Examples of Apps

Front-end web development has been overwhelmed by JavaScript highlights for quite a long time. Google, Facebook, Wikipedia, and most of all online pages use JS for customer side activities. As of late, it additionally made a shift to cross-platform mobile development as a main technology in React Native, Nativescript, Apache Cordova, and other crossover devices.

Throughout the most recent couple of years, Node.js moved to backend development as well. Designers need to utilize a similar tech stack for the whole web project without learning another language for server-side development. Node.js is a device that adjusts JS usefulness and syntax to the backend.

What is Node.js?

Node.js isn’t a language, or library, or system. It’s a runtime situation: commonly JavaScript needs a program to work, however Node.js makes appropriate settings for JS to run outside of the program. It’s based on a JavaScript V8 motor that can run in Chrome, different programs, or independently.

The extent of V8 is to change JS program situated code into machine code — so JS turns into a broadly useful language and can be perceived by servers. This is one of the advantages of utilizing Node.js in web application development: it expands the usefulness of JavaScript, permitting designers to coordinate the language with APIs, different languages, and outside libraries.

What Are the Advantages of Node.js Web Application Development?

Of late, organizations have been effectively changing from their backend tech stacks to Node.js. LinkedIn picked Node.js over Ruby on Rails since it took care of expanding responsibility better and decreased the quantity of servers by multiple times. PayPal and Netflix did something comparative, just they had a goal to change their design to microservices. We should investigate the motivations to pick Node.JS for web application development and when we are planning to hire node js developers.

Amazing Tech Stack for Web Development

The principal thing that makes Node.js a go-to environment for web development is its JavaScript legacy. It’s the most well known language right now with a great many free devices and a functioning local area. Node.js, because of its association with JS, immediately rose in ubiquity — presently it has in excess of 368 million downloads and a great many free tools in the bundle module.

Alongside prevalence, Node.js additionally acquired the fundamental JS benefits:

quick execution and information preparing;
exceptionally reusable code;
the code is not difficult to learn, compose, read, and keep up;
tremendous asset library, a huge number of free aides, and a functioning local area.

In addition, it’s a piece of a well known MEAN tech stack (the blend of MongoDB, Express.js, Angular, and Node.js — four tools that handle all vital parts of web application development).

Designers Can Utilize JavaScript for the Whole Undertaking

This is perhaps the most clear advantage of Node.js web application development. JavaScript is an unquestionable requirement for web development. Regardless of whether you construct a multi-page or single-page application, you need to know JS well. On the off chance that you are now OK with JavaScript, learning Node.js won’t be an issue. Grammar, fundamental usefulness, primary standards — every one of these things are comparable.

In the event that you have JS designers in your group, it will be simpler for them to learn JS-based Node than a totally new dialect. What’s more, the front-end and back-end codebase will be basically the same, simple to peruse, and keep up — in light of the fact that they are both JS-based.

A Quick Environment for Microservice Development

There’s another motivation behind why Node.js got famous so rapidly. The environment suits well the idea of microservice development (spilling stone monument usefulness into handfuls or many more modest administrations).

Microservices need to speak with one another rapidly — and Node.js is probably the quickest device in information handling. Among the fundamental Node.js benefits for programming development are its non-obstructing algorithms.

Node.js measures a few demands all at once without trusting that the first will be concluded. Many microservices can send messages to one another, and they will be gotten and addressed all the while.

Versatile Web Application Development

Node.js was worked in view of adaptability — its name really says it. The environment permits numerous hubs to run all the while and speak with one another. Here’s the reason Node.js adaptability is better than other web backend development arrangements.

Node.js has a module that is liable for load adjusting for each running CPU center. This is one of numerous Node.js module benefits: you can run various hubs all at once, and the environment will naturally adjust the responsibility.

Node.js permits even apportioning: you can part your application into various situations. You show various forms of the application to different clients, in light of their age, interests, area, language, and so on. This builds personalization and diminishes responsibility. Hub accomplishes this with kid measures — tasks that rapidly speak with one another and share a similar root.

What’s more, Node’s non-hindering solicitation handling framework adds to fast, letting applications measure a great many solicitations.

Control Stream Highlights

Numerous designers consider nonconcurrent to be one of the two impediments and benefits of Node.js web application development. In Node, at whatever point the capacity is executed, the code consequently sends a callback. As the quantity of capacities develops, so does the number of callbacks — and you end up in a circumstance known as the callback damnation.

In any case, Node.js offers an exit plan. You can utilize systems that will plan capacities and sort through callbacks. Systems will associate comparable capacities consequently — so you can track down an essential component via search or in an envelope. At that point, there’s no compelling reason to look through callbacks.

Final Words

So, these are some of the top benefits of Nodejs in web application development. This is how Nodejs is contributing a lot to the field of web application development.

I hope now you are totally aware of the whole process of how Nodejs is really important for your web project. If you are looking to hire a node js development company in India then I would suggest that you take a little consultancy too whenever you call.

Good Luck!

Original Source

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WebClues Infotech

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Hire Dedicated Node.js Developers - Hire Node.js Developers

If you look at the backend technology used by today’s most popular apps there is one thing you would find common among them and that is the use of NodeJS Framework. Yes, the NodeJS framework is that effective and successful.

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Node JS Development Advantages - How Your App Will Benefit From This JavaScript Framework

Web development has been controlling the JavaScript system features for many years. Many big online sites use Java Script for their everyday operations. And recently there has been a change and a shift towards cross-platform mobile application development. The main software frameworks in work these days are React native, apache Cordova, native script and hybrid tools. In the last ten years, Node.JS has been used as a backend development framework. Developers nowadays want to learn and use the same technologies for one entire website. They do not want to learn an entire language for server development. And Node.JS is able to adapt all the functions and syntaxes to the backend services from JavaScript. If you do not know the languages or syntaxes for Node JS development, you can look for an online guide. These guides have a detailed overview of the additional functions and basic systems. You will also find simple tasks in these guides. To read more click on the link.

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sophia tondon

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Top 10 NodeJs app Development Companies- ValueCoders

Node.js is a prominent tech trend in the space of web and mobile application development. It has been proven very efficient and useful for a variety of application development. Thus, all business owners are eager to leverage this technology for creating their applications.

Are you striving to develop an application using Node.js? But can’t decide which company to hire for NodeJS app development? Well! Don’t stress over it, as the following list of NodeJS app development companies is going to help you find the best partner.

Let’s take a glance at top NodeJS application development companies to hire developers in 2021 for developing a mind-blowing application solution.

Before enlisting companies, I would like to say that every company has a foundation on which they thrive. Their end goals, qualities, and excellence define their competence. Thus, I prepared this list by considering a number of aspects. While making this list, I have considered the following aspects:

Review and rating
Enlisted by software peer & forums
Hourly price
Offered services
Year of experience (Average 8+ years)
Credibility & Excellence
Served clients and more

I believe this list will help you out in choosing the best NodeJS service provider company. So, now let’s explore the top NodeJS developer companies to choose from in 2021.

#1. JSGuru

JSGuru is a top-rated NodeJS app development company with an innovative team of dedicated NodeJS developers engaged in catering best-class UI/UX design, software products, and AWS professional services.

It is a team of one of the most talented developers to hire for all types of innovative solution development, including social media, dating, enterprise, and business-oriented solutions. The company has worked for years with a number of startups and launched a variety of products by collaborating with big-name corporations like T-systems.

If you want to hire NodeJS developers to secure an outstanding application, I would definitely suggest them. They serve in the area of eLearning, FinTech, eCommerce, Telecommunications, Mobile Device Management, and more.

Ratings: 4.9/5.0
Founded: 2006
Headquarters: Banja Luka, Bosnia, and Herzegovina
Price: Starting from $50/hour

Visit Website - https://www.valuecoders.com/blog/technology-and-apps/top-node-js-app-development-companies

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Amelia Williams

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Node JS Development Company| Node JS Web Developers-SISGAIN

Top organizations and start-ups hire Node.js developers from SISGAIN for their strategic software development projects in Illinois, USA. On the off chance that you are searching for a first rate innovation to assemble a constant Node.js web application development or a module, Node.js applications are the most appropriate alternative to pick. As Leading Node.js development company, we leverage our profound information on its segments and convey solutions that bring noteworthy business results. For more information email us at hello@sisgain.com

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