JS u browser-u

JS u browser-u

JS izvan browsera

JS izvan browser-a

libuv

Generating a basic web server using Node.js and npm

Web Server

A web server is software designed to respond to requests over the internet by loading or processing data

HTTP - Hypertext transfer protocol

• Web servers follow Hypertext Transfer Protocol (HTTP)
• HTTP is a protocol which allows the fetching of resources
  • such as HTML documents
  • foundation of any data exchange on the Web
  • client-server protocol
  • requests are initiated by the recipient, usually the Web browser

GET and POST

• One way that a client  and server communicate is through HTTP verbs
• Verbs indicate what type of request is being made
  • the user is trying to load a new web page
  • the user is updating information in their profile page
• Two most widely used HTTP methods are GET and POST

Request-response cycle

Creating a Node.js module

Node.js modul

• A Node.js application is made up of many JavaScript files
• Each JavaScript file or folder containing a code library is called a module 

JavaScript objects and adding properties

export object and require function

Constructing a Node.js application with npm

npm

• npm - a package manager for Node.js
• npm is responsible for managing the external packages
  • install
  • remove
  • modify

npm

npm

• npm install <package>
  

  • --save
  • --global

• npm install <package>

  • -S
  • -g

• npm install <package>

  • --save-dev
  • --save-prod

Installing a Node.js package with npm

package.json

• Every Node.js application or module contains a package.json file
  • defines the properties of the project
• positioned at the root level of the project
• specifies:
  • the version of current release
  • the name of application
  • the main application file

package.json

Instalacija paketa

Instalacija paketa

Processing request and generating response

JavaScript functions

• Function is a "subprogram" that can be called by code external (or internal in the case of recursion) to the function
• In JavaScript, functions are first-class objects
  • they can have properties and methods like any object
  • what distinguishes them from other objects is that functions can be called
  • they are Function objects.

JavaScript arrow functions

• Arrow functions are anonymous functions with their own special syntax that accept a fixed number of arguments, and operate in the context of their enclosing scope - i.e. the function or other code where they are defined.

HTTP Status Codes

Callback function

• A callback is an anonymous function that’s set up to be invoked as soon as another function completes
  • benefit of using callbacks is that server
    doesn’t have to wait for the original function to complete processing before running other
    code

Callback function

Running a web server in your browser