Poppy Cooke

Poppy Cooke

1571729631

The Ultimate Node.js Beginner Tutorial

This tutorial is for all developers who want to program with Node.js but don’t know much about Node.js yet. Node.js is becoming more and more popular and every web developer should know at least the basics. After this tutorial you can clearly count yourself in this group.

So that you have a red thread through this Node.js Tutorial, I have you the points times summarized:

Table Of Contents

1. What is Node.js?

With Node.js the scripting language JavaScript has also found its way into server-side programming. Before Node.js JavaScript was mainly responsible for the frontend and the interaction with the visitor. With Node.js you can now develop from small CLI (Command Line) tools to complex programs and HTTP servers. Exactly this universal usability makes Node.js for me personally - and also for many other developers - so ingenious!

If you are wondering if you really need Node.js and want to be able to use it, you should read the most frequently asked questions below and decide if Node.js is the right technology for you.

Another important reason for the success are the on-board resources that come with Node.js. From the ground up, Node.js already has many features and modules that are easy to use. And to make the system even more perfect, there is the package manager - also called npm (Node Package Manager). More information can be found later in the Node.js Module section. Anyway, it’s very easy to add new features, like extensions from other developers.

That sounds promising at first, but can you imagine anything concrete about it? Probably not. At least it wouldn’t be very easy for me if I read something like this on a topic I didn’t know. Therefore read this section best at the end of this article once again and I assure you, you will know what I am talking about! ;)

2. Install Node.js

Before we can start programming, we first have to install Node.js on our computer. Now select the operating system you want to develop on. Windows or Mac…?

2.1 Windows

Under Windows you can simply download the installer and follow the installation instructions. It is best to download the LTS (Long-term support) version as it is already established and has fewer bugs than the latest version.
Windows Installer

2.2 Mac

On a Mac, just like Windows, you can download the official installer and follow the installation instructions. Also download the LTS (Long-term support) version, because it is already established and has less bugs than the latest version.
Mac Installer

2.3 Plesk (Hosting)

If you manage your domains with Plesk and want to host your app there, all you need is the Node.js extension, which you can download with a simple click.

Plesk GUI - Node.js Installation
To develop, however, you should work locally on your Mac or Windows computer. When your app is ready and you want to deploy it, you can use this guide to help you.

3. CLI

CLI stands for Command-Line Interface and means command line. On the Mac you can use the pre-installed program “Terminal” and on Windows the command prompt (cmd.exe).

Windows cmd.exe
With this we can “control” Node.js. With the command node we can now execute any JavaScript command. In the further course of this article you will now know what you can understand by the CLI.

4. Node.js Modules

The crown jewels of Node.js are its modules. At the beginning I already mentioned that Node.js has a package manager. The abbreviation and the command for the CLI is npm (Node Package Manager).

NPM is a gigantic network of development tools that can be downloaded free of charge for your application. If you work with Node.js, you’ll find that you have to rely on other developers’ modules over and over again. You don’t have to reinvent the wheel all the time.

In this example we download the express module:

npm install express

You can also install modules globally, which means it applies to your entire computer and is not only available in one project. Just append the parameter -g.

npm install -g express

When you install a module, the node_modules folder is automatically created. This folder contains all installed modules and can normally be ignored by you. We can include a module in the code later in this way:

const express = require('express');

5. First project

5.1 Create project

The time has come, we’re finally starting programming. To create a Node.js project, we simply create a normal folder in any directory. There we create an index.js, which is our start file.

Node.js Folder structure

5.2 Initialize Node.js App

Now we have to say in this folder that we want to make a Node.js app out of it, we do that with this command:

npm init

We are asked for different parameters like package name, version and description. You can fill in these fields or just leave them at their default values. We can change these settings later at any time.

npm init

5.3 package.json

A package.json file has now been created in our folder. This file contains all information about the author, version and most importantly, about all installed dependencies (modules).

// package.json

{
  "name": "app",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC"
}

5.4 Write program code

Now we can write the first JavaScript code in our index.js. Of course we can’t do without it and have to spend “Hello World”.

// index.js

console.log('Hello World');

5.5 Test application

The first code is written and we want to start our program. This is what we do with this command:

node index.js

We get this result, cool! 🥳

Node Hello World

6. Automatic App Restarts (Nodemon)

It’s really annoying when we have to manually restart our Node.js app after every little change to the code, isn’t it? Right, so there is the module nodemon, which we install globally. This module detects file changes and restarts the Node.js app within milliseconds. This speeds up our workflow enormously.

npm install -g nodemon

After the installation we start Nodemon with this command and immediately our app is started and restarted automatically when changes are made.

nodemon index.js

If you now save your files within the project folder, the Node.js app will automatically restart.

Nodemon Example

7. Browser output

Now we already want to set up our first small web server in order to be able to deliver content in the browser. Therefore we install the module express with the following command:

npm install express

And we adjust our index.js like this:

// index.js

const express = require('express');
const app = express();

app.get('/', (request, response) => {
  response.send('Our first Node.js webserver');
});

app.listen(3000, () => console.log('Server running on port 3000'));

To help you understand everything, here is an explanation line by line:
Line 3: Integration of the express module.
Line 4: Initialization of the express module in the variable app.
Line 6: We intercept the page call from / to our server to perform an action.
Line 7: We send the text “Our first Node.js webserver” back to the requestor as an answer.
Line 9: We start our web server on port 3000 and display a message in the console.

If we ask for browser now our computer on the port 3000, we get this result:

Browser tab Node.js Example

Simple, isn’t it? That’s why Node.js is so brilliant. You only need seven lines of code for your own web server.

If we now adjust our route a little bit, we can return data that has already been transferred:

// index.js

const express = require('express');
const app = express();

app.get('/:yourName', (req, res) => {
  res.send('Your name: ' + req.params.yourName);
});

app.listen(3000, () => console.log('Server running on port 3000'));

Here :yourName stands for a variable string that we can pass in our URL and with req.params.yourName we can read it and send the name back to the user.

If we now call http://localhost:3000/test, we get the string with the given name as response. So you can already read and send data with really little code.

8. FAQ

When do I use Node.js?

Node.js is primarily used for “normal” dynamic websites and backend APIs (RestAPIs). In addition, Node.js is often used in applications that need to process data in real time (e.g. chats).

Is Node.js a programming language?

Definitely no. Node.js connects the scripting language JavaScript and a network component. Since Node.js was developed on the Google V8 JavaScript engine, Node.js masters the basics of network technology such as the HTTP, DNS and TCP protocols.

Is it easy to learn Node.js?

Since Node.js is not a framework and not a programming language, you have to ask yourself if it is easy to learn JavaScript. Surveys have shown that JavaScript is one of the easiest scripting languages to learn.

What is middleware?

A middleware is a part-program, i.e. a function that is executed between two components. For example, if the user calls /settings, the actual program code should only be executed if the user is logged on. To do this, you write a middleware function and call this function before. This is done so that the same code (checking the login) can be used several times, but only has to be written once.

How and where can I host a Node.js app?

For example, you can host Node.js Apps for free at Heroku.

What does the package.json do?

The package.json at Node.js Apps contains information about the name, the author, and much more. Most important are the dependencies. This is a list of the modules (dependencies) your app uses. You can also use scripts to define commands to run or test your app.

What does the node_modules folder do?

The node_modules folder contains all modules included in your node.js. This folder contains standard modules, but also all modules that you have additionally installed and that are listed in the package.json under scripts. You don’t need to push the node_modules folder into your git repository or live hosting, because the npm install command will download all modules into the folder again.

Conclusion

Pooh! Quite a lot of information at once, isn’t it? Nevertheless I hope that you got a good impression of what is possible with Node.js and I made you curious for more. If so, you are welcome to continue looking around on webdeasy.de and read even more exciting articles about web development. You are welcome to write any unsettled questions in the comments! :)

#node #nodejs #node.js #web-development

What is GEEK

Buddha Community

The Ultimate Node.js Beginner Tutorial

very cool

NBB: Ad-hoc CLJS Scripting on Node.js

Nbb

Not babashka. Node.js babashka!?

Ad-hoc CLJS scripting on Node.js.

Status

Experimental. Please report issues here.

Goals and features

Nbb's main goal is to make it easy to get started with ad hoc CLJS scripting on Node.js.

Additional goals and features are:

  • Fast startup without relying on a custom version of Node.js.
  • Small artifact (current size is around 1.2MB).
  • First class macros.
  • Support building small TUI apps using Reagent.
  • Complement babashka with libraries from the Node.js ecosystem.

Requirements

Nbb requires Node.js v12 or newer.

How does this tool work?

CLJS code is evaluated through SCI, the same interpreter that powers babashka. Because SCI works with advanced compilation, the bundle size, especially when combined with other dependencies, is smaller than what you get with self-hosted CLJS. That makes startup faster. The trade-off is that execution is less performant and that only a subset of CLJS is available (e.g. no deftype, yet).

Usage

Install nbb from NPM:

$ npm install nbb -g

Omit -g for a local install.

Try out an expression:

$ nbb -e '(+ 1 2 3)'
6

And then install some other NPM libraries to use in the script. E.g.:

$ npm install csv-parse shelljs zx

Create a script which uses the NPM libraries:

(ns script
  (:require ["csv-parse/lib/sync$default" :as csv-parse]
            ["fs" :as fs]
            ["path" :as path]
            ["shelljs$default" :as sh]
            ["term-size$default" :as term-size]
            ["zx$default" :as zx]
            ["zx$fs" :as zxfs]
            [nbb.core :refer [*file*]]))

(prn (path/resolve "."))

(prn (term-size))

(println (count (str (fs/readFileSync *file*))))

(prn (sh/ls "."))

(prn (csv-parse "foo,bar"))

(prn (zxfs/existsSync *file*))

(zx/$ #js ["ls"])

Call the script:

$ nbb script.cljs
"/private/tmp/test-script"
#js {:columns 216, :rows 47}
510
#js ["node_modules" "package-lock.json" "package.json" "script.cljs"]
#js [#js ["foo" "bar"]]
true
$ ls
node_modules
package-lock.json
package.json
script.cljs

Macros

Nbb has first class support for macros: you can define them right inside your .cljs file, like you are used to from JVM Clojure. Consider the plet macro to make working with promises more palatable:

(defmacro plet
  [bindings & body]
  (let [binding-pairs (reverse (partition 2 bindings))
        body (cons 'do body)]
    (reduce (fn [body [sym expr]]
              (let [expr (list '.resolve 'js/Promise expr)]
                (list '.then expr (list 'clojure.core/fn (vector sym)
                                        body))))
            body
            binding-pairs)))

Using this macro we can look async code more like sync code. Consider this puppeteer example:

(-> (.launch puppeteer)
      (.then (fn [browser]
               (-> (.newPage browser)
                   (.then (fn [page]
                            (-> (.goto page "https://clojure.org")
                                (.then #(.screenshot page #js{:path "screenshot.png"}))
                                (.catch #(js/console.log %))
                                (.then #(.close browser)))))))))

Using plet this becomes:

(plet [browser (.launch puppeteer)
       page (.newPage browser)
       _ (.goto page "https://clojure.org")
       _ (-> (.screenshot page #js{:path "screenshot.png"})
             (.catch #(js/console.log %)))]
      (.close browser))

See the puppeteer example for the full code.

Since v0.0.36, nbb includes promesa which is a library to deal with promises. The above plet macro is similar to promesa.core/let.

Startup time

$ time nbb -e '(+ 1 2 3)'
6
nbb -e '(+ 1 2 3)'   0.17s  user 0.02s system 109% cpu 0.168 total

The baseline startup time for a script is about 170ms seconds on my laptop. When invoked via npx this adds another 300ms or so, so for faster startup, either use a globally installed nbb or use $(npm bin)/nbb script.cljs to bypass npx.

Dependencies

NPM dependencies

Nbb does not depend on any NPM dependencies. All NPM libraries loaded by a script are resolved relative to that script. When using the Reagent module, React is resolved in the same way as any other NPM library.

Classpath

To load .cljs files from local paths or dependencies, you can use the --classpath argument. The current dir is added to the classpath automatically. So if there is a file foo/bar.cljs relative to your current dir, then you can load it via (:require [foo.bar :as fb]). Note that nbb uses the same naming conventions for namespaces and directories as other Clojure tools: foo-bar in the namespace name becomes foo_bar in the directory name.

To load dependencies from the Clojure ecosystem, you can use the Clojure CLI or babashka to download them and produce a classpath:

$ classpath="$(clojure -A:nbb -Spath -Sdeps '{:aliases {:nbb {:replace-deps {com.github.seancorfield/honeysql {:git/tag "v2.0.0-rc5" :git/sha "01c3a55"}}}}}')"

and then feed it to the --classpath argument:

$ nbb --classpath "$classpath" -e "(require '[honey.sql :as sql]) (sql/format {:select :foo :from :bar :where [:= :baz 2]})"
["SELECT foo FROM bar WHERE baz = ?" 2]

Currently nbb only reads from directories, not jar files, so you are encouraged to use git libs. Support for .jar files will be added later.

Current file

The name of the file that is currently being executed is available via nbb.core/*file* or on the metadata of vars:

(ns foo
  (:require [nbb.core :refer [*file*]]))

(prn *file*) ;; "/private/tmp/foo.cljs"

(defn f [])
(prn (:file (meta #'f))) ;; "/private/tmp/foo.cljs"

Reagent

Nbb includes reagent.core which will be lazily loaded when required. You can use this together with ink to create a TUI application:

$ npm install ink

ink-demo.cljs:

(ns ink-demo
  (:require ["ink" :refer [render Text]]
            [reagent.core :as r]))

(defonce state (r/atom 0))

(doseq [n (range 1 11)]
  (js/setTimeout #(swap! state inc) (* n 500)))

(defn hello []
  [:> Text {:color "green"} "Hello, world! " @state])

(render (r/as-element [hello]))

Promesa

Working with callbacks and promises can become tedious. Since nbb v0.0.36 the promesa.core namespace is included with the let and do! macros. An example:

(ns prom
  (:require [promesa.core :as p]))

(defn sleep [ms]
  (js/Promise.
   (fn [resolve _]
     (js/setTimeout resolve ms))))

(defn do-stuff
  []
  (p/do!
   (println "Doing stuff which takes a while")
   (sleep 1000)
   1))

(p/let [a (do-stuff)
        b (inc a)
        c (do-stuff)
        d (+ b c)]
  (prn d))
$ nbb prom.cljs
Doing stuff which takes a while
Doing stuff which takes a while
3

Also see API docs.

Js-interop

Since nbb v0.0.75 applied-science/js-interop is available:

(ns example
  (:require [applied-science.js-interop :as j]))

(def o (j/lit {:a 1 :b 2 :c {:d 1}}))

(prn (j/select-keys o [:a :b])) ;; #js {:a 1, :b 2}
(prn (j/get-in o [:c :d])) ;; 1

Most of this library is supported in nbb, except the following:

  • destructuring using :syms
  • property access using .-x notation. In nbb, you must use keywords.

See the example of what is currently supported.

Examples

See the examples directory for small examples.

Also check out these projects built with nbb:

API

See API documentation.

Migrating to shadow-cljs

See this gist on how to convert an nbb script or project to shadow-cljs.

Build

Prequisites:

  • babashka >= 0.4.0
  • Clojure CLI >= 1.10.3.933
  • Node.js 16.5.0 (lower version may work, but this is the one I used to build)

To build:

  • Clone and cd into this repo
  • bb release

Run bb tasks for more project-related tasks.

Download Details:
Author: borkdude
Download Link: Download The Source Code
Official Website: https://github.com/borkdude/nbb 
License: EPL-1.0

#node #javascript

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.

If you wish to have a strong backend for efficient app performance then have NodeJS at the backend.

WebClues Infotech offers different levels of experienced and expert professionals for your app development needs. So hire a dedicated NodeJS developer from WebClues Infotech with your experience requirement and expertise.

So what are you waiting for? Get your app developed with strong performance parameters from WebClues Infotech

For inquiry click here: https://www.webcluesinfotech.com/hire-nodejs-developer/

Book Free Interview: https://bit.ly/3dDShFg

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Aria Barnes

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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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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Vincent Lab

Vincent Lab

1605177692

How to Use Template Engines for Beginners in Node.js

In this video, I will be showing you what a templating engine is by showing you 3 different templating engines the ones we will look at it is pug, mustache and ejs.

#node js tutorial #node js templating #node js templates #nodejs for beginners #mustache templating #mustache.js