JWT Decoding jwt-decode is a small browser library that helps decoding JWTs token which are Base64Url encoded. NOTE: This library doesn't validate the token, any well formed JWT can be decoded. You should validate the token in your server-side logic Instalation Run npm install jwt-decode or yarn add jwt-decode to install the library. Usage import jwt_decode from "jwt-decode";

INTRODUCTION In the first 4 weeks of this bootcamp we learned how to design and build backend part Rest API to be used by any client want to integrate. After that we talked about Front-end and SPA using ReactJS, but we didn't integrate Front-end with Rest API. To integrate front-end with back-end Rest API we have to make http requests. Today we will learn how to integrate front-end with backend Rest API using axios library, so we will implement CRUD operations. AXIOS Axios is a Javascript library used to make HTTP requests from node.js or XMLHttpRequests from the browser and it supports the Promise API that is native to JS ES6. It can be used intercept HTTP requests and responses and enables client-side protection against XSRF. It also has the ability to cancel requests.

Component Lifecycle Each component has several lifecycle methods that you can override to run code at particular times in the process. Mounting Mounting means putting elements into the DOM. React has four built-in methods that gets called, in this order, when mounting a component: constructor() getDerivedStateFromProps() render()

What is ReactJS? Free & open source Java script library Used for building user interfaces or UI components. Developed and maintained by Meta in addition community of individual developers and companies. Used for building SPA. Why ReactJS? Small learning curve.

Security how to make sure our web applications are secure. Env. files and configuration Environment variables allow us to manage the configuration of our applications separately from our codebase. Common examples of configuration data that are stored in environment variables include: HTTP port database connection string

MongoDB What is MongoDB? MongoDB is a document-oriented NoSQL database used for high volume data storage. Instead of using tables and rows as in the traditional relational databases, MongoDB makes use of collections and documents. Documents consist of key-value pairs which are the basic unit of data in MongoDB. Collections contain sets of documents and function which is the equivalent of relational database tables. Main Features Each database contains collections which in turn contains documents. Each document can be different with a varying number of fields. The size and content of each document can be different from each other. The document structure is more in line with how developers construct their classes and objects in their respective programming languages. Developers will often say that their classes are not rows and columns but have a clear structure with key-value pairs. The rows (or documents as called in MongoDB) doesn’t need to have a schema defined beforehand. Instead, the fields can be created on the fly. The data model available within MongoDB allows you to represent hierarchical relationships, to store arrays, and other more complex structures more easily.

INTRODUCTION Node.js is an open-source and cross-platform JavaScript runtime environment. Node.js runs the V8 JavaScript engine, the core of Google Chrome, outside of the browser. This allows Node.js to be very performant. A Node.js app runs in a single process with single thread. Node.js runs non-blocking, asynchronous programming, which is very memory efficient. Node.js provides a set of asynchronous I/O primitives in its standard library that prevent JavaScript code from blocking How Node.js handles a file request

INTRODUCTION Javascript Stack that is used for easier and faster deployment of full-stack web applications. The four open-source technologies in the MERN stack include MongoDB, Express, React and Node.JS which are all open source technologies that you can use to build your next full-stack application. The acronym “MERN” stands for MongoDB, Express, React and Node.JS. NODEJS EXPRESS JS MONGODB REACTJS