React js is a free and open-source front-end JavaScript library for building user interfaces based on UI components. It allows creating reusable UI components that can be nested to build complex applications. A React component may maintain internal state and re-render when data changes. React uses a declarative paradigm that makes code more predictable and easier to debug.
To use React, install Node packages and create a new project using create-react-app. Components let you break up the UI into reusable pieces responsible for rendering HTML. Components can be stateful class components or stateless function components. Components can be created using ES6 class syntax or function syntax and can be nested. Choosing between class and function depends on requirements like using
ReactJS is arguably the most popular Javascript framework around for web development today. With more and more teams exploring and adopting React, here is TechTalks presentation elaborating fundamentals of React, in a code along session
This document provides an overview of React including:
- React is a JavaScript library created by Facebook for building user interfaces
- It uses virtual DOM to efficiently re-render components on updates rather than entire page
- React supports ES6 features and uses classes, arrow functions, and other syntax
- Popular tools for React include Create React App for setting up projects and React Dev Tools for debugging
React is a JavaScript library for building user interfaces. It is not a full framework and only handles the view layer. React uses a component-based approach where UI is broken into independent, reusable pieces. Components render HTML and have their own internal state. This makes components predictable and easier to debug. However, React alone is not enough to build full applications and must be used with other libraries for functionality like data fetching and routing. While React takes more time to learn initially, it can improve development speed and code quality for larger teams through its patterns and emphasis on component design.
React Js Basic Details and Descriptions
Frontend Javascript Library, to make decent SPA
The fastest way to build a segregated component based front end for software development.
This document contains an agenda and slides for a React workshop presented by Bojan Golubovic. The workshop covers the history and basics of React, including components, JSX, the virtual DOM, and React data flow. It also discusses related tools like Redux and React Router. The goal is to provide basic knowledge of React and how to build real-world applications with it.
This document provides an introduction to React.js, including:
- React is a JavaScript library for building user interfaces and was developed by Facebook. It is the VIEW component in MVC architecture.
- Key features and benefits of React include being fast, modular, scalable, flexible, and popular due to its employability. Large companies like Facebook use React.
- Core concepts of React include JSX, components, unidirectional data flow, and the virtual DOM which improves performance compared to traditional frameworks. Components are reusable pieces that make up the entire application.
React is a declarative, efficient, and flexible JavaScript library for building user interfaces. It uses virtual DOM which improves performance and can render on both client and server. React encourages a component-based approach where UI is broken into independent reusable pieces that accept external data through properties. Components manage their own state which allows the UI to update over time in response to user input. This makes React code more predictable and easier to debug than traditional two-way data binding.
React JS is a JavaScript library for building user interfaces. It uses virtual DOM and one-way data binding to render components efficiently. Everything in React is a component - they accept custom inputs called props and control the output display through rendering. Components can manage private state and update due to props or state changes. The lifecycle of a React component involves initialization, updating due to state/prop changes, and unmounting from the DOM. React promotes unidirectional data flow and single source of truth to make views more predictable and easier to debug.
The session will provide the knowledge about react page life cycle and how more precise actions or operations can be performed using react hooks concepts
- React is a JavaScript library for building user interfaces that uses a virtual DOM for faster re-rendering on state changes.
- Everything in React is a component that can have states, props, and lifecycle methods like render(). Components return JSX elements.
- Props are used for passing data to components in a unidirectional flow, while states allow components to re-render on changes.
- The render() method returns the view, accessing props and state values. Forms and events also follow React conventions.
React is an open source JavaScript library for building user interfaces. It was created by Jordan Walke at Facebook in 2011 and is now maintained by Facebook, Instagram, and a community of developers. Major companies like Facebook, Netflix, Instagram, Khan Academy, and PayPal use React to build their interfaces. React uses a virtual DOM for faster rendering and makes components that manage their own state. It uses JSX syntax and a one-way data flow that is declarative and composable.
The document discusses React's virtual DOM and how it allows for more efficient DOM updates compared to directly manipulating the real DOM. It explains that the virtual DOM is an in-memory representation of the real DOM that allows React to calculate efficient DOM changes before applying them to the real DOM. This avoids unnecessary re-renders and improves performance. It also describes how React uses a diff algorithm and DOM traversal with breadth-first search to determine the minimal number of operations needed to transform the virtual DOM before updating the real DOM in a batched way.
Introduction to React in combination with Redux. Redux helps you to develop applications in a simple way while having features like time-travel available during development.
This document provides an introduction to React.js, including:
- React.js uses a virtual DOM for improved performance over directly manipulating the real DOM. Components are used to build up the UI and can contain state that updates the view on change.
- The Flux architecture is described using React with unidirectional data flow from Actions to Stores to Views via a Dispatcher. This ensures state changes in a predictable way.
- Setting up React with tools like Browserify/Webpack for module bundling is discussed, along with additional topics like PropTypes, mixins, server-side rendering and React Native.
ReactJS is a JavaScript library for building user interfaces using reusable and interactive UI components. It uses a virtual DOM for rendering UI components and follows a unidirectional data flow architecture. Major companies using ReactJS include Facebook, Instagram, AirBnB, and Khan Academy. ReactJS advantages include its use of components, JSX syntax, and debugging tools. Components are the basic building blocks and use props, state, and lifecycles. Flux is a common architecture used with ReactJS that involves a central store for managing data in a unidirectional flow.
React Interview Question & Answers PDF By ScholarHatScholarhat
React is a popular JavaScript library for building user interfaces. It utilizes a virtual DOM for efficient rendering and a component-based approach that promotes reusability and modularity. Some key features of React include its reusable UI components, fast virtual DOM, and rich ecosystem of tools and libraries. Understanding core concepts like components, props, state, and unidirectional data flow is important for developing large-scale React applications.
ReactJs Training in Hyderabad | ReactJS Trainingeshwarvisualpath
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React JS is a JavaScript library for building reusable UI components. It uses a virtual DOM for efficient rendering. Components are the building blocks of React, and can be either functional or class-based. Functional components are simpler while class components can maintain state. Props are passed down from parent to child components while state is local. The virtual DOM improves performance by only updating the real DOM with actual changes.
React JS is a declarative, efficient, and flexible JavaScript library for building reusable UI components. It uses a virtual DOM which works like a lightweight copy of the real DOM to improve performance by only updating what changes. Components are independent and reusable bits of code that serve the same purpose as functions but return HTML. There are two main types of components - functional components which are simple functions, and class components which can maintain their own state and work together.
React components are the building blocks of React applications. There are two types of components in React - functional components and class components. Functional components are simple JavaScript functions that return JSX, while class components are ES6 classes that can maintain internal state and pass data between other components. Components render reusable pieces of UI and the entire application UI is composed of different individual components.
React JS is a frontend library for building user interfaces using components. It uses a virtual DOM and declarative programming. Components can be either functional or class-based. Functional components return JSX, while class components can maintain internal state. Events are handled by passing callbacks, and forms use controlled components by storing values in component state.
React Best Practices All Developers Should Follow in 2024.pdfBOSC Tech Labs
Stay ahead with these crucial React best practices for 2024. Learn how to optimize your React applications for performance, maintainability, and scalability.
React JS; all concepts. Contains React Features, JSX, functional & Class comp...Karmanjay Verma
This ppt contains all concepts of React JS. This contains React Features JSX, functional & Class component, Hooks. PPT includes sample code also for each defination in comment.
For more detail and source code
https://github.com/KPCodeLearning/React-Learning-App
https://kpcodelearning.github.io/React-Learning-App/
https://www.linkedin.com/in/karmanjayverma/
Getting Started with React, When You’re an Angular DeveloperFabrit Global
If you’re an Angular developer looking into expanding your stack with React, this presentation will come in handy! It is an insightful introduction to React in comparison with Angular, where you will find all the basic knowledge you need to get started.
We’ll deep-dive into tech details such as:
● Virtual DOM
● JSX
● Functional vs Class-Based Components
● State
● How to Style
● Requests
● Upgrading: Redux and Flux and more!
You can also check out the full article version here: https://blog.fabritglobal.com/product-development/getting-started-with-react-angular-developer/
Mildaintrainings offers advanced ReactJS Interview Questions 2019 that helps you in cracking your interview & acquire your dream career as ReactJS Developer. Visit in this link :- https://mildaintrainings.com/blogs/react-js-interview-questions-answers/
If you want to get trained in React and wish to develop interesting UI’s on your own, then check out the ReactJS with Redux Certification Training by MildainTrainings, a trusted online learning company with a network of more than 50,000 satisfied learners spread across the globe.
The document provides an overview of React including:
- React is a declarative, efficient JavaScript library for building user interfaces using components.
- Components are the building blocks of React apps and allow complex apps to be built from simple reusable pieces.
- The document then discusses JSX, components, props, state, and installing React using Create React App.
How to increase the ui performance of apps designed using react MoonTechnolabsPvtLtd
Performance optimization of an application designed using React is a vital factor to consider, especially if you hope to increase the speed of the solution. Here you’ll find a few easy-to-implement techniques to take the performance standards of your app to the next level.
The document discusses React, a JavaScript library for building user interfaces. It begins by explaining what React is, its core principles of being declarative, efficient and flexible. It then covers React basics like using JSX syntax, maintaining a virtual DOM, one-way data flow and building reusable components. The document also provides examples of adding state and properties to components. Finally, it discusses thinking in React and walks through building a searchable product table as an example.
Learn Stateful and Stateless components in ReactJS RajasreePothula3
ReactJS, known simply as React, is an open-source JavaScript library that is ideal for developing user interfaces, specifically for single-page applications. It empowers developers to create reusable UI components, which makes developing complex UIs more manageable and efficient. But who is it for, exactly?
React Interview Questions and Answers by ScholarhatScholarhat
React Interview Questions and Answers provides a comprehensive collection of commonly asked questions about React to help prepare for interviews. It covers key topics like what React is, components, JSX, props, state, lifecycle methods, hooks, event handling, and higher-order components. The document aims to boost confidence and knowledge for acing React interviews.
React and its component structure
● What are Hooks?
● React Hooks and their capabilities
● Migrating Your Existing Apps to React Hooks
● Combine Existing React Hooks into New Custom Hooks
● Benefits of using React Hooks
● Best Practices
The following features are associated with reacting to lifecycle methods.Wikiance
A JavaScript library for building fast and interactive interfaces for mobile and web applications, React is built for web and mobile development.A front-end component-based library that only handles the application's view layer.
The DealBook is our annual overview of the Ukrainian tech investment industry. This edition comprehensively covers the full year 2023 and the first deals of 2024.
Coordinate Systems in FME 101 - Webinar SlidesSafe Software
If you’ve ever had to analyze a map or GPS data, chances are you’ve encountered and even worked with coordinate systems. As historical data continually updates through GPS, understanding coordinate systems is increasingly crucial. However, not everyone knows why they exist or how to effectively use them for data-driven insights.
During this webinar, you’ll learn exactly what coordinate systems are and how you can use FME to maintain and transform your data’s coordinate systems in an easy-to-digest way, accurately representing the geographical space that it exists within. During this webinar, you will have the chance to:
- Enhance Your Understanding: Gain a clear overview of what coordinate systems are and their value
- Learn Practical Applications: Why we need datams and projections, plus units between coordinate systems
- Maximize with FME: Understand how FME handles coordinate systems, including a brief summary of the 3 main reprojectors
- Custom Coordinate Systems: Learn how to work with FME and coordinate systems beyond what is natively supported
- Look Ahead: Gain insights into where FME is headed with coordinate systems in the future
Don’t miss the opportunity to improve the value you receive from your coordinate system data, ultimately allowing you to streamline your data analysis and maximize your time. See you there!
Quantum Communications Q&A with Gemini LLM. These are based on Shannon's Noisy channel Theorem and offers how the classical theory applies to the quantum world.
Are you interested in dipping your toes in the cloud native observability waters, but as an engineer you are not sure where to get started with tracing problems through your microservices and application landscapes on Kubernetes? Then this is the session for you, where we take you on your first steps in an active open-source project that offers a buffet of languages, challenges, and opportunities for getting started with telemetry data.
The project is called openTelemetry, but before diving into the specifics, we’ll start with de-mystifying key concepts and terms such as observability, telemetry, instrumentation, cardinality, percentile to lay a foundation. After understanding the nuts and bolts of observability and distributed traces, we’ll explore the openTelemetry community; its Special Interest Groups (SIGs), repositories, and how to become not only an end-user, but possibly a contributor.We will wrap up with an overview of the components in this project, such as the Collector, the OpenTelemetry protocol (OTLP), its APIs, and its SDKs.
Attendees will leave with an understanding of key observability concepts, become grounded in distributed tracing terminology, be aware of the components of openTelemetry, and know how to take their first steps to an open-source contribution!
Key Takeaways: Open source, vendor neutral instrumentation is an exciting new reality as the industry standardizes on openTelemetry for observability. OpenTelemetry is on a mission to enable effective observability by making high-quality, portable telemetry ubiquitous. The world of observability and monitoring today has a steep learning curve and in order to achieve ubiquity, the project would benefit from growing our contributor community.
Performance Budgets for the Real World by Tammy EvertsScyllaDB
Performance budgets have been around for more than ten years. Over those years, we’ve learned a lot about what works, what doesn’t, and what we need to improve. In this session, Tammy revisits old assumptions about performance budgets and offers some new best practices. Topics include:
• Understanding performance budgets vs. performance goals
• Aligning budgets with user experience
• Pros and cons of Core Web Vitals
• How to stay on top of your budgets to fight regressions
Scaling Connections in PostgreSQL Postgres Bangalore(PGBLR) Meetup-2 - MydbopsMydbops
This presentation, delivered at the Postgres Bangalore (PGBLR) Meetup-2 on June 29th, 2024, dives deep into connection pooling for PostgreSQL databases. Aakash M, a PostgreSQL Tech Lead at Mydbops, explores the challenges of managing numerous connections and explains how connection pooling optimizes performance and resource utilization.
Key Takeaways:
* Understand why connection pooling is essential for high-traffic applications
* Explore various connection poolers available for PostgreSQL, including pgbouncer
* Learn the configuration options and functionalities of pgbouncer
* Discover best practices for monitoring and troubleshooting connection pooling setups
* Gain insights into real-world use cases and considerations for production environments
This presentation is ideal for:
* Database administrators (DBAs)
* Developers working with PostgreSQL
* DevOps engineers
* Anyone interested in optimizing PostgreSQL performance
Contact info@mydbops.com for PostgreSQL Managed, Consulting and Remote DBA Services
Transcript: Details of description part II: Describing images in practice - T...BookNet Canada
This presentation explores the practical application of image description techniques. Familiar guidelines will be demonstrated in practice, and descriptions will be developed “live”! If you have learned a lot about the theory of image description techniques but want to feel more confident putting them into practice, this is the presentation for you. There will be useful, actionable information for everyone, whether you are working with authors, colleagues, alone, or leveraging AI as a collaborator.
Link to presentation recording and slides: https://bnctechforum.ca/sessions/details-of-description-part-ii-describing-images-in-practice/
Presented by BookNet Canada on June 25, 2024, with support from the Department of Canadian Heritage.
AC Atlassian Coimbatore Session Slides( 22/06/2024)apoorva2579
This is the combined Sessions of ACE Atlassian Coimbatore event happened on 22nd June 2024
The session order is as follows:
1.AI and future of help desk by Rajesh Shanmugam
2. Harnessing the power of GenAI for your business by Siddharth
3. Fallacies of GenAI by Raju Kandaswamy
How to Avoid Learning the Linux-Kernel Memory ModelScyllaDB
The Linux-kernel memory model (LKMM) is a powerful tool for developing highly concurrent Linux-kernel code, but it also has a steep learning curve. Wouldn't it be great to get most of LKMM's benefits without the learning curve?
This talk will describe how to do exactly that by using the standard Linux-kernel APIs (locking, reference counting, RCU) along with a simple rules of thumb, thus gaining most of LKMM's power with less learning. And the full LKMM is always there when you need it!
GDG Cloud Southlake #34: Neatsun Ziv: Automating AppsecJames Anderson
The lecture titled "Automating AppSec" delves into the critical challenges associated with manual application security (AppSec) processes and outlines strategic approaches for incorporating automation to enhance efficiency, accuracy, and scalability. The lecture is structured to highlight the inherent difficulties in traditional AppSec practices, emphasizing the labor-intensive triage of issues, the complexity of identifying responsible owners for security flaws, and the challenges of implementing security checks within CI/CD pipelines. Furthermore, it provides actionable insights on automating these processes to not only mitigate these pains but also to enable a more proactive and scalable security posture within development cycles.
The Pains of Manual AppSec:
This section will explore the time-consuming and error-prone nature of manually triaging security issues, including the difficulty of prioritizing vulnerabilities based on their actual risk to the organization. It will also discuss the challenges in determining ownership for remediation tasks, a process often complicated by cross-functional teams and microservices architectures. Additionally, the inefficiencies of manual checks within CI/CD gates will be examined, highlighting how they can delay deployments and introduce security risks.
Automating CI/CD Gates:
Here, the focus shifts to the automation of security within the CI/CD pipelines. The lecture will cover methods to seamlessly integrate security tools that automatically scan for vulnerabilities as part of the build process, thereby ensuring that security is a core component of the development lifecycle. Strategies for configuring automated gates that can block or flag builds based on the severity of detected issues will be discussed, ensuring that only secure code progresses through the pipeline.
Triaging Issues with Automation:
This segment addresses how automation can be leveraged to intelligently triage and prioritize security issues. It will cover technologies and methodologies for automatically assessing the context and potential impact of vulnerabilities, facilitating quicker and more accurate decision-making. The use of automated alerting and reporting mechanisms to ensure the right stakeholders are informed in a timely manner will also be discussed.
Identifying Ownership Automatically:
Automating the process of identifying who owns the responsibility for fixing specific security issues is critical for efficient remediation. This part of the lecture will explore tools and practices for mapping vulnerabilities to code owners, leveraging version control and project management tools.
Three Tips to Scale the Shift Left Program:
Finally, the lecture will offer three practical tips for organizations looking to scale their Shift Left security programs. These will include recommendations on fostering a security culture within development teams, employing DevSecOps principles to integrate security throughout the development
Video traffic on the Internet is constantly growing; networked multimedia applications consume a predominant share of the available Internet bandwidth. A major technical breakthrough and enabler in multimedia systems research and of industrial networked multimedia services certainly was the HTTP Adaptive Streaming (HAS) technique. This resulted in the standardization of MPEG Dynamic Adaptive Streaming over HTTP (MPEG-DASH) which, together with HTTP Live Streaming (HLS), is widely used for multimedia delivery in today’s networks. Existing challenges in multimedia systems research deal with the trade-off between (i) the ever-increasing content complexity, (ii) various requirements with respect to time (most importantly, latency), and (iii) quality of experience (QoE). Optimizing towards one aspect usually negatively impacts at least one of the other two aspects if not both. This situation sets the stage for our research work in the ATHENA Christian Doppler (CD) Laboratory (Adaptive Streaming over HTTP and Emerging Networked Multimedia Services; https://athena.itec.aau.at/), jointly funded by public sources and industry. In this talk, we will present selected novel approaches and research results of the first year of the ATHENA CD Lab’s operation. We will highlight HAS-related research on (i) multimedia content provisioning (machine learning for video encoding); (ii) multimedia content delivery (support of edge processing and virtualized network functions for video networking); (iii) multimedia content consumption and end-to-end aspects (player-triggered segment retransmissions to improve video playout quality); and (iv) novel QoE investigations (adaptive point cloud streaming). We will also put the work into the context of international multimedia systems research.
Data Protection in a Connected World: Sovereignty and Cyber Securityanupriti
Delve into the critical intersection of data sovereignty and cyber security in this presentation. Explore unconventional cyber threat vectors and strategies to safeguard data integrity and sovereignty in an increasingly interconnected world. Gain insights into emerging threats and proactive defense measures essential for modern digital ecosystems.
UiPath Community Day Kraków: Devs4Devs ConferenceUiPathCommunity
We are honored to launch and host this event for our UiPath Polish Community, with the help of our partners - Proservartner!
We certainly hope we have managed to spike your interest in the subjects to be presented and the incredible networking opportunities at hand, too!
Check out our proposed agenda below 👇👇
08:30 ☕ Welcome coffee (30')
09:00 Opening note/ Intro to UiPath Community (10')
Cristina Vidu, Global Manager, Marketing Community @UiPath
Dawid Kot, Digital Transformation Lead @Proservartner
09:10 Cloud migration - Proservartner & DOVISTA case study (30')
Marcin Drozdowski, Automation CoE Manager @DOVISTA
Pawel Kamiński, RPA developer @DOVISTA
Mikolaj Zielinski, UiPath MVP, Senior Solutions Engineer @Proservartner
09:40 From bottlenecks to breakthroughs: Citizen Development in action (25')
Pawel Poplawski, Director, Improvement and Automation @McCormick & Company
Michał Cieślak, Senior Manager, Automation Programs @McCormick & Company
10:05 Next-level bots: API integration in UiPath Studio (30')
Mikolaj Zielinski, UiPath MVP, Senior Solutions Engineer @Proservartner
10:35 ☕ Coffee Break (15')
10:50 Document Understanding with my RPA Companion (45')
Ewa Gruszka, Enterprise Sales Specialist, AI & ML @UiPath
11:35 Power up your Robots: GenAI and GPT in REFramework (45')
Krzysztof Karaszewski, Global RPA Product Manager
12:20 🍕 Lunch Break (1hr)
13:20 From Concept to Quality: UiPath Test Suite for AI-powered Knowledge Bots (30')
Kamil Miśko, UiPath MVP, Senior RPA Developer @Zurich Insurance
13:50 Communications Mining - focus on AI capabilities (30')
Thomasz Wierzbicki, Business Analyst @Office Samurai
14:20 Polish MVP panel: Insights on MVP award achievements and career profiling
In this follow-up session on knowledge and prompt engineering, we will explore structured prompting, chain of thought prompting, iterative prompting, prompt optimization, emotional language prompts, and the inclusion of user signals and industry-specific data to enhance LLM performance.
Join EIS Founder & CEO Seth Earley and special guest Nick Usborne, Copywriter, Trainer, and Speaker, as they delve into these methodologies to improve AI-driven knowledge processes for employees and customers alike.
What Not to Document and Why_ (North Bay Python 2024)Margaret Fero
We’re hopefully all on board with writing documentation for our projects. However, especially with the rise of supply-chain attacks, there are some aspects of our projects that we really shouldn’t document, and should instead remediate as vulnerabilities. If we do document these aspects of a project, it may help someone compromise the project itself or our users. In this talk, you will learn why some aspects of documentation may help attackers more than users, how to recognize those aspects in your own projects, and what to do when you encounter such an issue.
These are slides as presented at North Bay Python 2024, with one minor modification to add the URL of a tweet screenshotted in the presentation.
Interaction Latency: Square's User-Centric Mobile Performance MetricScyllaDB
Mobile performance metrics often take inspiration from the backend world and measure resource usage (CPU usage, memory usage, etc) and workload durations (how long a piece of code takes to run).
However, mobile apps are used by humans and the app performance directly impacts their experience, so we should primarily track user-centric mobile performance metrics. Following the lead of tech giants, the mobile industry at large is now adopting the tracking of app launch time and smoothness (jank during motion).
At Square, our customers spend most of their time in the app long after it's launched, and they don't scroll much, so app launch time and smoothness aren't critical metrics. What should we track instead?
This talk will introduce you to Interaction Latency, a user-centric mobile performance metric inspired from the Web Vital metric Interaction to Next Paint"" (web.dev/inp). We'll go over why apps need to track this, how to properly implement its tracking (it's tricky!), how to aggregate this metric and what thresholds you should target.
2. | What is Reacts js |
React is a free and open-source front-end JavaScript library for building
user interfaces based on UI components. It is created by Facebook. A React
application is made of multiple components, each responsible for rendering
a small, reusable piece of HTML. Components can be nested within other
components to allow complex applications to be built out of simple
building blocks. A component may also maintain an internal state – for
example, a TabList component may store a variable corresponding to the
currently open tab. React uses a declarative paradigm that makes it easier
to reason about your application and aims to be both efficient and
flexible. It designs simple views for each state in your application, and
React will efficiently update and render just the right component when
your data changes. The declarative view makes your code more predictable
and easier to debug.
3. | How to Use & Environment Setup |
React. js is an open-source JavaScript library that is used for building
user interfaces specifically for single-page applications. It's used for
handling the view layer for web and mobile apps. React also allows us to
create reusable UI components.
Prerequisites: Download Node packages with their latest version.
Example: Create a new React project by using the command below:
Syntax: npx create-react-app app_name
And to run the React app we can use the command “npm start” and it’ll load
the react app in local host i.e. localhost:3000
4. | Components |
React components let you break up the user interface into separate pieces that can
then be reused and handled independently. A React component takes an optional
input and returns a React element which is rendered on the screen.
A React component can be either “stateful” or “stateless.”
“Stateful” components are of the class type, while “stateless” components are of
the function type.
5. | Creating a Simple Component |
In React, you don’t need to create a class or functional-based component
with lines of code just to print "Hello World." The component can be
created with ES6 syntax in a single line, In this example, the ES6 arrow
function has been used. This is the smallest component we can create for a
React app.
In the example on the left hand side, the
component is created in the same file and
consumed within the render() function as
<HelloWorld /> So when you run this
example, the output will be the static
string.
6. | Creating a Class-Based Component |
In React, a component can also be written using ES6 classes syntax, using
the arrow function i.e. “=>” Class-based components are a widely used
approach to creating components in React if an app requires the state to
be used.
Create a class-based component like this:
As you can see in the above
example, Component is being
imported from the package react,
which allows us to convert the
class into the component using ES6
syntax. Apart from
the component keyword, the file
also has an additional section
called render () that is the
function used to render the
various HTML elements into the DOM
once the business logic has been
implemented.
You can embed another class-based
child component into any class-
based component as, explained in
7. | Creating a Function-Based Component |
You can also create a component in React using the function-based approach, which
uses the normal JavaScript function. To use a function-based component, export
the function using the export keyword. The functional component can look like
this:
As you can see in the example, a
function-based component is created
called FunctionComponent, and from
return (), the element is returned just
as it would be from a class-based
component. One thing to notice in the
example is that the arrow function has
been used to create the component;
hence, we can also use the keyword
function, as explained below.
You can choose any one of the options shown
to create a function-based component that
can be exported and consumed into other
components.
8. | Choosing Component |
Well, it completely depends on your
structural requirements, but there
are advantages to each. Use a class
component if you want to use local
state, different lifecycle hooks,
multiple event handlers, or dynamic
state values based on user activity.
Use a function component when you
don’t need to write business logic
and just need to render specific UI
elements based on the props value,.
Using hooks, you can use state into
the function component as well.
| Conclusion |
In this part, you have learned that what a component is and
how to create a component using the class-based approach and
the function-based approach. You can choose either of those
two options to create a component based on the business
requirements of your ReactJs app.
9. | Introducing Hooks |
Hooks are a new addition in React 16.8. They let you use state and other React
features without writing a class. This new function useState is the first “Hook”
we’ll learn about.
No Breaking Changes
Before we continue, note that Hooks are:
• Completely opt-in. You can try Hooks in a
few components without rewriting any
existing code. But you don’t have to learn
or use Hooks right now if you don’t want
to.
• 100% backwards-compatible. Hooks don’t
contain any breaking changes.
• Available now. Hooks are now available
with the release of v16.8.0.
There are no plans to remove classes from
React.
Hooks let you use more of React’s features
without classes.
10. Hooks don’t replace your knowledge of React concepts. Instead, Hooks provide a
more direct API to the React concepts you already know: props, state, context,
refs, and lifecycle. As we will show later, Hooks also offer a new powerful way
to combine them.
With Hooks, you can extract stateful logic from a component so it can be tested
independently and reused. Hooks allow you to reuse stateful logic without
changing your component hierarchy. This makes it easy to share Hooks among many
components or with the community.
In many cases it’s not possible to break components into smaller ones because the
stateful logic is all over the place. It’s also difficult to test them. This is
one of the reasons many people prefer to combine React with a separate state
management library. However, that often introduces too much abstraction, requires
you to jump between different files, and makes reusing components more difficult.
To solve this, Hooks let you split one component into smaller functions based on
what pieces are related (such as setting up a subscription or fetching data),
rather than forcing a split based on lifecycle methods. You may also opt into
managing the component’s local state with a reducer to make it more predictable.
| Hooks |
11. | Advantages Of Hooks |
For React developers, Hooks convey ample benefits as follows:
• It revolutionizes the way you write components
• You can write concise and clearer code.
• Hooks are simpler to work with and test. Code would appear cleaner and easier to read.
• A related logic could be tightly coupled inside a custom hook.
• It simplifies how to make code more composable and reusable.
• Unlike HOCs, they don’t create another element in DOM.
• Hooks would work more efficiently with the future React optimizations. For example, it would work
ahead of time compilation as well as components folding.
• Components folding may be implemented in the future. It suggests that for code elimination at
compile-time, hooks are simple to reuse the stateful logic.
12. | State and Props |
State
The state is an updatable structure that is used to contain data or information about the component and
can change over time. The change in state can happen as a response to user action or system event. It is
the heart of the react component which determines the behaviour of the component and how it will render.
A state must be kept as simple as possible. It represents the component's local state or information. It can
only be accessed or modified inside the component or by the component directly.
Props
Props are read-only components. It is an object which stores the value of attributes of a tag and work
similar to the HTML attributes. It allows passing data from one component to other components. It is similar
to function arguments and can be passed to the component the same way as arguments passed in a
function. Props are immutable so we cannot modify the props from inside the component.
15. | Redux |
React Redux is the official React binding for Redux. It allows React components to
read data from a Redux Store, and dispatch Actions to the Store to update data.
Redux helps apps to scale by providing a sensible way to manage state through a
unidirectional data flow model. React Redux is conceptually simple. It subscribes
to the Redux store, checks to see if the data which your component wants have
changed, and re-renders your component.
Now Redux is basically a global store. It doesn’t matter where you push things in
to the Redux store as you can see in the above picture you have access to it
everywhere you can access this from every single component so its actually two
way communication you can push anything into the global store at any point and
you can also pull things from that global store at any point.
Why is Redux good with React?
This is because React was designed with the concept of states and lifecycles.
And in React, state can also not be modified directly, it can only be done
via the function setState. This makes it easier for Redux concepts to be
applied because they share they same understanding and behavior of a state
object.
17. How Redux works?
The way Redux works is simple. There is a central store that holds the entire state of
the application. Each component can access the stored state without having to send
down props from one component to another.
There are three core components in Redux — actions, store, and reducers.
What are Redux actions?
Simply put, Redux actions are events. They are the only way you can send data from
your application to your Redux store. The data can be from user interactions, API
calls, or even form submissions. Actions are plain JavaScript objects that must have a
type property to indicate the type of action to be carried out, and a payload object
that contains the information that should be used to change the state. Actions are
created via an action creator, which in simple terms is a function that returns an
action. And actions are executed using the store.dispatch() method which sends the
action to the store.
What are Redux reducers?
Reducers are pure functions that take the current state of an application, perform
an action, and return a new state. The reducer handles how the state (application
data) will change in response to an action. “A pure function is a function that
will always return the same value if given the same parameters. i.e. the function
depends on only the parameters and no external data.” It is based on the reduce
function in JavaScript, where a single value is calculated from multiple values
after a callback function has been carried out.
18. What is Redux Store?
The store is a “container” (really a JavaScript object) that holds the application
state, and the only way the state can change is through actions dispatched to the
store. Redux allows individual components connect to the store and apply changes to
it by dispatching actions. It is highly recommended to keep only one store in any
Redux application. You can access the state stored, update the state, and register
or unregister listeners via helper methods.
Redux middleware
Redux allows developers to intercept all actions dispatched from components before
they are passed to the reducer function. This interception is done via middleware.
Building on the example login component discussed in the last section, we might want
to sanitize the user’s input before it reaches our store for further processing. This
can be achieved via Redux middleware. Technically, middleware are functions that call
the next method received in an argument after processing the current action. These
are called after every dispatch.
Why use Redux?
When using Redux with React, states will no longer need to be lifted up. This makes
it easier for you to trace which action causes any change. As you can see in the
example above, the component does not need to provide any state or method for its
children components to share data among themselves. Everything is handled by Redux.
This greatly simplifies the app and makes it easier to maintain. This is the primary
reason why you should use Redux, but it’s not the only benefit. Take a look at the
list below for a summary of what you stand to gain by using Redux for state
management.
19. | Firebase |
It is a mobile application development platform from Google with powerful features
for developing, handling, and enhancing applications. Firebase is a backend
platform for building web and mobile applications.
Firebase is fundamentally a collection of tools developers can rely on, creating
applications and expanding them based on demand.
Firebase aims to solve three main problems for developers:
• Build an app, fast
• Release and monitor an app with confidence
• Engage users,
Developers relying on this platform get access to services that they would have to
develop themselves, and it enables them to lay focus on delivering robust
application experiences.
Some of the Google Firebase platform’s standout features include databases,
authentication, push messages, analytics, file storage, and much more.
Since the services are cloud-hosted, developers can smoothly perform on-demand
scaling without any hassle. Firebase is currently among the top app development
platforms relied upon by developers across the globe.
20. | Advantages |
1. Free to start
2. Development speed
3. End-to-end app development platform
4. Powered by Google
5. Developers can focus on frontend development
6. It’s serverless
7. It offers machine learning capabilities
8. Generates traffic to your apps
9. Error monitoring
10.Security
1. It’s not Open-Source
2. Vendor Lock-In
3. Firebase does not work in many countries
4. Only NoSQL databases are available
5. Slow Queries
6. Not all services are free to start
7. It’s not cheap and pricing is difficult to forecast
8. Runs only on Google Cloud
9. Dedicated Servers & Enterprise Support are not an option
10.Does not provide GraphSQL APIs
| Limitations |
21. Firebase Privacy
Firebase Privacy Policy supports GDRP – General Data Protection Regulation from
European Union and CCPA- California Consumer Privacy act. Also, Firebase complies
with multiple ISO and SOC certifications, including 27001, 27017, 27018, SOC1,
SOC2, and SOC3. Firebase feeds service data to Google for non-Firebase services.
This option is selected by default; to avoid it; users must uncheck the box.
Firebase Build Features
Build is an expansive feature set of Firebase with various components that enable
developers to stay on top of their application development requirements.
Authentication is a Firebase feature offering ready-to-use UI libraries, backends,
and convenient SDKs for user application authentication. Authentication is
supported through phone numbers, passwords, and providers such as Google, Twitter,
Facebook, and others. Authentication enjoys integration with different Firebase
services, and it makes use of OpenID Connect and OAuth 2.0 and allows custom
backend integration.
Hosting Firebase has various scalable and agile hosting features for Microservices,
web apps, and several other content types. Content can be hosted across different
categories, and users have the ability to avail SSL protection and single-click
rollbacks. (34)
22. | Advantages of React JS|
•Intuitive
ReactJS is extremely intuitive to work with and provides interactivity to the layout of any
UI. Plus, it enables fast and quality assured application development that in turn saves
tome for both - clients and developers.
•Declarative
ReactJS enables significant data changes that result in automatic alteration in the selected
parts of user interfaces. Owing to this progressive functionality, there is no additional
function that you need to perform to update your user interface.
•Provides Reusable Components
ReactJS provides reusable components that developers have the authority to reuse and create
a new application . Reusability is exactly like a remedy for developers. This platform gives
the developers the authority to reuse the components build for some other application having
the same functionality. Thereby, reducing the development effort and ensuring a flawless
performance.
•JavaScript library
A strong blend of JavaScript and HTML syntax is always used, which automatically simplifies
the entire process of writing code for the planned project. The JS library consists several
functions including one that converts the HTML components into required functions and
transforms the entire project so that it is easy to understand.
•Components Support
ReactJS is a perfect combination of JavaScript and HTML tags. The usage of the HTML tags and
JS codes, make it easy to deal with a vast set of data containing the document object model.
During this time, ReactJS works as a mediator which represents the DOM and assists to decide
which component needs changes to get the exact results.