What is React?

React is an independent and open-source front-end JavaScript library for building user interfaces.The current version of React 18 provides developers with improved features to create a Great User Experience. Some of the improvements are

• Automatic Batching: Groups all state updates which in turn improves performance.
• Transitions: Is now more sophisticated and differentiates between urgent and non-urgent user interactions.
• React Suspense: Allows for better Server-side rendering and improves the User Experience. as well as Performance

Let’s look at these in a bit more detail

1. Automatic Batching:
   

   Batching is one of the React features that combines all the updated states in a single update. Batched updates can be performed inside React event handlers, i.e., it only worked inside the synchronous React event handlers functions. These changes were made in React version 18 with automatic batching.In the example code below, it shows how the automatic batching helps to stop re-rendering the set Counter () function twice.

   

2. Transitions:
   

   Transition is an advanced concept introduced in React 18 that helps to differentiate between urgent and non-urgent updates.

   • Urgent Update: It reflects direct interaction like typing, clicking, pressing etc. This visual feedback is high priority for users.
   • Non-urgent Update: Non-urgent updates are not vital to the user like searching, which can be marked as no-urgent updates.

   For such use cases, startTransitions and useTransitions methods are used.

   • useTransitions: useTransitions is a hook concept that begins transitions, in addition to a value to track the pending state.
   • startTransitions: startTransitions is a method to initialize start transition where hooks can’t be used. Below is the example for startTransition where you can put your code which is non-vital to the end user.
     

3. Suspense:
   

   Suspense lets you declaratively specify the loading state for some of the component tree if it’s not prepared to be displayed. Suspense in React version 18 functions better when combined with transitions API. while you suspend the time of transition, React will halt already-visible content from being altered by a fallback. Rather, React will stop or delay the rendering until enough data has loaded to prevent an inferior loading state.
   Below is the example for Suspense that explains how to use a fallback property of it to show the loading state to the end-user.

   Concurrency

   Concurrency is the most important addition in React version 18. It is a confidential mechanism that makes it possible for React to prepare multiple versions of UI.

   For these, React uses a “dispatcher” internally which is responsible to compile and combine the callbacks.

   Before React 18, the user did not have any way to control the appeal order of these functions. Since the release of React version 18, React is providing some authority to this event loop to the user with a Transition API.

   How to upgrade to React version 18?

   You will need to install React 18 and DOM using npm/yarn.

   npm install react react-dom

   npm install react@latest react-dom@latest

   

   After upgrading to version 18, the following changes need to be made in the Index.js file:

   Note: – There is an error in the console while upgrading to version 18.
   
   To fix this console issue, the index.js is converted to the latest React version 18, which recommends a new root API. This new root API provides a user-friendly system for executing roots. The new root API also enables the new concurrent re-renders which fastens the coexisting features.
   
   Our React developers have experience of building complex applications using React technology. They use the latest Dev tools such as React-Redux, React Hooks, React Router, React Bootstrap etc. If you would like to develop a mobile or web application using React technology, then please feel free to contact us.

What is React? 

You may not judge a book by its cover, but a web application gets assessed by the visual aesthetics of the User Interface (UI) and its functionalities. React is a JavaScript library that provides front-end developers an incredible framework and hence is getting increasingly popular. Aside from the encapsulated and reusable components, the customization features enable developers to build complex UI with simple views. Creating secure, responsive, and interactive web applications is no longer a challenging task but an exciting innovation with the sophisticated React.js framework.  

If you foresee a career or aspire to become a sought-after web app developer, you want to get well-versant with ReactJS.  

Which are the must-have skills you need to stack up? (Pun intended!)

Top 9 Must-Have React Developer Skills in 2022 

1. Hypertext Markup Language (HTML)+ Cascading Style Sheets (CSS)

Honing any skill always starts with getting the basics right. If you are a front-end developer, get familiar with HTML and CSS languages before moving into ReactJS. The more thorough you are, the firmer the foundation for constructing a well-developed page, website, and eventually an application. Well-scripted codes deliver a cleaner user experience.

Ensure you know how to: 

• Write the code for semantic HTML tags and use them 
• Use CSS for Inline styling  
• Build responsive CSS layouts with the box-sizing properties 
• Use Flexbox for creating beautiful and reusable components
• Implement CSS reset to avoid cross-browser differences 
• Apply the three main design principles—fluid grid system, flexible images, and media queries
  

2. JSX (JavaScript XML) + Babel
   

Simply put, JSX is the syntax extension of JavaScript that allows you to write HTML in React. JSX expressions simplify writing component codes and rendering tree-like structures of React elements. Essentially, JSX helps developers create simpler and elegant pieces of code even when they are large blocks. Developers familiar with HTML and CSS will appreciate the ease of building React applications with JSX.  

However, to implement JSX, you require the transcompiler—Babel that converts the ECMAScript2015 (ES6) + source code into a backward-compatible version of JavaScript. The toolchain helps you use modern JavaScript language features. 

3. JavaScript Fundamentals + ECMAScript 6 (ES6)

React is fundamentally JavaScript, and that is why knowing the programming language features and having substantial experience working with it is necessary for a front-end developer. The 6th version of the ECMAScript that standardized the JavaScript has certain modern features to take note of: 

• Arrow Functions 
• Variables (let, const, var) 
• Array Methods  
• Destructuring 
• Modules
• Ternary Operator 
• Spread Operator 

The new features will enable you to write asynchronous code making the process more efficient. 

4. Hooks

Hooks is a super-cool feature that makes a coder’s life far easier. Ask any experienced React developer, and they would tell you what a nightmare it was to refactor class components and render props with verbose code before Hooks got released in 2018. Hooks simplified the methods of updating the state and implementing the lifecycles of function components.  

Working with Hooks will help you improve the user interface with enhanced code readability, reusability, and testability.  

5. Virtual Document Object Model (VDOM) and Event Handling Facility

The biggest drawback of the actual DOM was that any manipulation of a single element in the tree structure would trigger the framework to rebuild every object. The more updates to the DOM, the slower the operations got, making it very cumbersome for developers. That problem got resolved only after the innovation of the Virtual DOM (VDOM). The React VDOM virtually handles all the changes made to the objects but updates only the necessary changes to those particular objects in the actual DOM when everything is finalized, thus saving you precious time.  

6. NodeJS + Node Package Manager (NPM)

Using NodeJS is NOT a prerequisite for ReactJS web app development but can definitely accelerate projects if utilized in combination. While ReactJS takes care of the front-end aesthetics of the web application, Node is a JavaScript language that is ideal for backend development. NodeJS helps maintain continuous streaming and server load balance for real-time data-intensive web applications. The full-stack JS framework improves scalability and speeds up code execution.  

Use the NPM cloud registry for managing all NodeJS package repositories or dependencies and the JavaScript libraries.  

7. Redux

One of the most important aspects of web applications is that they are expected to behave consistently across client, server, and native environments and must be easy to test, too.  You need Redux, the state management library for ReactJS to centralize and manage the global state of the application or to maintain specific patterns while updating the state.  

8. Technical Application Skills

Aside from having a command of the JavaScript language and system architecture, you must have knowledge and expertise of certain other tools crucial for writing clean code for the front-end development of ReactJS applications.  

• Build tools for component visualization 
• Modular bundle analyzer  
• Development automation tools 
• Tools for reporting crashes and managing testers, or beta version distribution tool. 
• Testing utilities or code evaluation tool to confirm if it complies with the JS 
• Form building API or libraries 
• Debugging extensions

9. Soft Skills

Even as you check every box for technical skills, your soft skills are equally important. You might want to cultivate these soft skills that employers or clients will value in a front-end developer: – 

• Creativity 
• Emotional intelligence 
• Clarity in communication  
• Learning/ Growth mindset 
• A keen eye for detail/observation  
• Critical/Analytical thinking 
• Time management, especially with deadlines 
• People management/ interpersonal skills 
• Accountability 
• Problem-solving attitude 
• Team player’s spirit 

 What Is the Future for React Developers? 

The post-Covid world has grown more digital than ever before. We rely on web/mobile applications for everything from buying groceries to improving physical and mental health. The growing majority of organizations are now showing a preference for ReactJS while creating a digital platform for their business since it provides a speedy, scalable, easy-to-maintain, and extremely SEO-friendly environment. Consequently, there is a noticeable upsurge in the demand for developers with a robust ReactJs skillset. And there’s no trough to this wave anytime soon!  

 Build on the 9 ReactJS skills, related technical skills, and 11 soft skills shared here. 

Create engaging web applications.  

And find yourself in the league of the most sought-after ReactJS developers of 2022.   

MetaSys React team makes the best use of all the new exciting features of React like React Hooks, React Bootstrap, React Redux and React Router to build complex web and mobile applications. So if you have any such requirement, then please feel free to contact our React Programmers.  

In a React application, we can pass data from parent component to child components using the prop. However, this is limited to certain type of properties such as Theme, locale preference, etc., which need to be used at global level in the application. With React Context, we can use the data or props without explicitly passing them as props to the component.

Context has three main elements. We need to understand these elements to utilize Context to the fullest.

1. Context Object – The Context object is designed to share data globally in the application.
2. Context Provider – The Context object comes with a provider that can be used to consume Context data in the React component.
3. Context Consumer – The Context Consumer is wrapped inside the Context provider, and it is used to get access to the Context data.

In this article, let us see how to create a Theme Context using typescript step by step.

1.Create Theme Context Object. Export ThemeContext and set the Context default value to ‘undefined’.

2.Create the Theme object by using two Themes, for instance, here we are going to use ‘dark’ and ‘light’.

3.Create Theme Context provider.

4.We created the Theme Context Provider by setting the Default Theme and function to change the Theme.

5.Subscribe Theme Context by wrapping the component with Context provider.

6.Use or set the Context data as shown in the screenshot below.

The concept of Context is simple yet effective. In this article, we covered how to use Context in the React Application with Theme Context example using TypeScript.

Should you have any queries, please contact MetaSys Software React experts, who have abundant experience in engineering applications using latest dev-tools such as React-Redux, React Hooks, React Router, React Bootstrap, etc.

You can reach out to us with any coding queries too! We would be happy to help!

Happy Coding!

My intention behind writing this blog is to help React-native developers create their own package. If any developer wants to share his own package on the NPM registry, then he needs to make it public. This allows developers to contribute to the NPM ecosystem. Steps to create and publish a react-native NPM package are as follows:

There are 3 phases to create and publish a package.

1. Creating the NPM package.
2. Testing the NPM package on the react-native app.
3. Publishing on the NPM website.

1. Creating the NPM package:

First create a folder where package information like package.json, .babelrc, webpack.config.js, etc will be stored. We will introduce these files soon.

Now navigate into that folder directory using terminal and run command – npm init

You will be prompted for the package name, version, main, keyword, etc. You can skip questions (by pressing enter) (it is easy to modify later). At this point, a package.json file will be created.

Now, open the package.json file in your IDE (code editor) and install all the dependencies as below using – npm install dependency-name.

Below is an example of package.json file.

Note: “main” should be the same as above.

Now create a file .babelrc and add the following lines. Babel is a compiler to convert JavaScript code into ES5 JavaScript.

Let’s create a file named webpack.config.js and add the lines below.
Remember, webpack is the builder. It compresses code into ‘build’ that can be deployed in the React-Native app. Make sure “entry” is either ./src/index.js or ./index.js depending upon your file structure.

Now, create a folder src, add the index.js file and add your component.

Whenever you make any change to your package, you have to create the build again using command – npm run build. After that, you must re-install it in the react-native app.

Once you configure the above steps, your folder structure should look as follows

2. Testing the package on React-Native app:

To test or use your package, you will need a React-Native app. Create a React-Native app by executing the run command npm create-react-app “your app name” and open it in your IDE.

You can install your package in two ways

1. Upload it on the NPM website and then install it using npm i “package name”.
2. Locally install it through a relative path of NPM package to react-native app npm i ../react-test-library

Note: We will try to avoid the first option because whenever there is any change in your NPM package, you have to re-publish it on the NPM website and re-install it on your project.

So we will test it locally first and then upload it on the NPM website.

To check your package, you have to install it through the relative path as shown in the above example and import your component from your package.

src/App.js

To see the result of the installed package, run the command in your react-native app – npm start.

Now, let’s see the final step.

3. Publishing on the NPM website:

For publishing any package, you should have an account on the NPM website (if not you can create one). While uploading the same package, the package version should be unique each time.

Steps to upload your package –

1. Using the terminal, navigate to your package directory.
2. Run command – npm login. Enter a username, password, and email id.
3. Run command – npm publish.

Once your package has been published, you can check it on the NPM website.

At last, you are able to create your own library. In case of any queries feel free to share your feedback in the comments section below.

Happy Coding…

There are two main aspects to internationalization, firstly the detection of the user’s local language, and secondly the modification of the content, including translation of the text, and switching relevant items such as currency.

This article addresses how to implement the internationalization of a React application using the library ‘React-intl’. The first step is to create a new React project and add the intl package:

• Create a React project using the commands –

$ npx create-react-app project_i18n

         $ cd project_i18n

• Add the ‘react-intl’ package.

Configuration of the package consists of four main steps: creating the locales, creating the provider, and finally creating a common translator. In the remainder of this article, I will elaborate on these steps.

1. Create the locales –

a.Create a folder with the name ‘i18n’ in your code folder.

b.Create a file ‘locale.js’ and export the locales object.

2. Create the provider –

a.Now, let’s create the Provider to hook the IntlProvider to the application.

In the above image, IntlProvider is imported from react-intl and a wrapper is created for the application, setting the default locale and passing the message content according to the locale.

b.To create the messages for the respective languages, create a folder called ‘MessageContent’ and create the locale files for messages within that folder.
Let us create two different message objects.
For English: – en-US.js –

For French:- fr-CA.js –

c. Create an ‘js’ file under the MessageContent folder to export the messages.
MessageContent-> index.js –

3. Create a common translator –

a.Let us create a common Translate function to translate the message according to the locale.
i18n-> translate.js –

b.Create ‘index.js’ under the ‘i18n’ folder to export the locales and provider as default.
i18n-> index.js –

c.Finally, let us wrap the application with IntlProvider and set the locale in App.js.
src-> App.js –

Example for French Locale –

fr-CA.js

export default {

[LOCALES.FRENCH]: { ‘hello’: ‘Bonjour’, ‘userName’: ‘le nom d\’ utilisateur est {uname}’

}

};

translate.js

const translate = (id, value={}) => <FormattedMessage id={id} values={{…value}}/>

d. We are looking for the following output:

translate(‘hello’)  => Bonjour

translate(‘userName’, {‘uname’: ‘Sam’}) => le nom d’ utilisateur est Sam

Internationalization can be achieved in react application by using ‘React-intl’ with minimal development efforts for handling multiple languages.

MetaSys has developed custom React solutions for clients across various industries and geographies. If you have any questions on internationalization in your React projects, then please feel free to contact us. Happy coding!

React Native and Flutter are currently competing with each other to become the leading product, and although both have their advantages, it is not yet clear which one will come out on top. This article compares the technologies by examining their features, and their respective advantages and disadvantages. We hope this can help you in choosing which technology to use for your application.

Before looking at the technical differences, let us briefly have a look at their positions in the market so far. In order to do this, we can use Google trends to look at the interest in the technologies since 2015, when React Native was launched.

The trend shows that both technologies have been gaining popularity steadily, and that although React Native is much older, Flutter is catching up quickly.

About Flutter

• Flutter is a free, open-source portable UI toolkit for creating web, desktop, and natively compiled mobile apps in a single codebase.
• It was created by Google in 2017.
• It uses a language named Dart.

 About React Native

• React Native is also a free, open-source mobile application framework.
• It enables the developers to use its parent framework React with the native platform.
• React was created by Facebook in March 2015.
• React Native is virtually identical to React.

Head to head comparison between Flutter and React Native

Let’s list a few of the major advantages and disadvantages of each technology.

Flutter

Advantages:

• Fast apps
• User-friendly design
• Perfect for MVC structure

Disadvantages:

• Large Apps can be difficult to program
• Limited libraries in comparison with React Native
• Currently small developer community (though growing)

React Native

Advantages:

• Active large community
• Uses widely popular JavaScript language
• Robust Performance
• Easy to learn

Disadvantages:

• Lots of abandoned libraries and packages
• App size is bigger than Natively developed Apps
• Fewer testing features compared to Flutter

Which technology should we choose in 2020?

React Native has a huge base of achievements to showcase its success in the market, compared to the new player. However, Flutter has a lot of potential and as of now there is a chance that it can become the leading technology for cross platform mobile app development and web applications. We hope that this article has highlighted some of the key differences and can help you choose the best technology for your app development.

Happy Coding…

To illustrate the advantages of this approach, have a look at the UI structure shown below.

Let’s say the functionality required is that when a user interacts with the big component, the application has to update the small component and the header. In other words, we need to sync the header and small component as well as manage the states of all the other components. Without a state management library such as the one provided by Redux, coding this implementation can easily become very complicated.

Using the state functionality in React allows only the use of local, component level states.

You can store the states using setState method, and fetch the stored state using state.[STATE_NAME]. However, these states are local, and only available within the class component in which it is declared.

To store the states at the application level, i.e. the global level, in order to access them from different components, we can use React-Redux.

Let’s see how React-Redux works

You will see three main elements in the Redux architecture – Store, Dispatch Actions and Reducers.

Store: holds the states at the application level, and allows any component to get data from the store in the form of Redux States.

Dispatch Action: a function of the Redux Store to trigger a state change.

Reducers: It handles the value change in Redux State.

How to configure React Redux in a React JS project –

The following packages are needed to be installed to configure  Redux in the project –

1. Redux: the core package of React Redux.
2. React-redux: needed for React bindings.
3. Redux-thunk: a middleware which allows you to call action creators, and which returns a function instead of the action object.

These dependencies can be installed by using the following NPM command –
“npm install redux react-redux redux-thunk –save”

After these dependencies are installed, a store can be created and initialized with data/null values as per the requirements. This can be done by creating the file store.js in the project.

First however, you need to create reducer.js to handle the next states. Below is the example of reducer.js to initialize the state. Here, it is just returning the initial value from the reducer.

Below is a slightly more complex example of the code in reducer.js to update the states based on the action executed from the component.

In the above example, it adds the data to the state upon the dispatch action (ADD_DATA). Now let’s create the action to dispatch. You can create a file with the name action.js, that contains the code shown below.

Once the action is created, now you can create a store and then connect the store to the application. You can create a file with the name store.js, that contains the code shown below.

To connect the store to the application, you will have to use the entry point. In the index.js (i.e. entry point of the app), import the store as shown below –

These are all the Redux configurations for an application. Refer the the image below to use it in your component –

React Redux can handle large amounts of data at the application level with cleaner components and is particularly useful for big applications.

Without redux, to transfer data from component 1 to component 5, you need to pass it through middle components. This increases the props for components and creates more complexity and the components are less clean.

Using React-Redux, you can get or set the data to the store from any of the components directly by mapping the redux states to component props. In this case, you do not need to pass props to the middle components. This allows for much cleaner components and increased clarity in the code.

If you are looking to build a mobile or web application using React technology, then please feel free to contact us.

React Hooks are functions that allow you to hook into React lifecycle and state features. They primarily serve as an alternative for classes. They can help in keeping your components clean and perform better. Hooks are a recent  addition in React version 16.8.0.

In this article, we are going to show you how to convert a React class into a functional component using the useState Hook.

Hooks don’t work inside classes because they let you use React without classes. We will use the built-in hooks instead of React lifecycle methods. Eg. useState, useEffect, useRef etc.

We are covering useState, useEffect, useRef React hooks in this article. useState() is used to replace the constructor functions and state declarations. While useEffect() is used to replace componentDidMount() and componentDidUpdate(). You can use useEffect as many times as you need to in single component. And the last one, useRef has another cool usage besides DOM refs, it is also a generic container whose current property is mutable, it also can hold any value similar to an instance property of a class.

Steps to convert a React class component into a functional component using React Hooks –

Step 1. Change ‘class ComponentName extends Component’ With ‘function ComponentName(props)‘

Step 2. Remove “this.” And “this.state” from the entire component.

Step 3. import React, { useState } from ‘react’

Step 4. Remove the constructor. Add its logic as shown above in the image for initializing the state variables with the help of useState hook.

Let’s understand conversion into useState, useEffect and useRef with examples –

• useState() Hook –

The parameter of the useState hook is the initial value of the state. This hook provides the array with two values – the first is the name of the state and the second is the function name which updates the value of that state.

Eg.

const [num, setNum] = useState(0); //declaration

setNum(10) //use

Here num is the state name, setCount is the function that you can use anywhere in the component to update that state.

Here are some examples of setting or initializing state variables for different data types –

//Set an Integer

const [num, setNum] = useState(0);

setNum(10);

//Set a String

const [name, setUsername] = useState(‘John’);

setUsername(‘Smith’);

//Set a Boolean

const [isValid, setIsValid] = useState(false);

setIsValid(true);

//Set and Array

const [items, setItems] = useState([]);

setItems([0,1,2,3,4]);

setItems([{id:0, color:”red”},{id:1, color:”green”},{id:2, color:”blue”}]);

//Set and Object

const [form, setValues] = useState({

id: 0,

firstName: ‘’,

lastName: ‘’,

subscribe: false

})

setValues({

…form,

firstName: ‘Jamie’,

subscribe: true

})

• Replace lifecycle methods (compentDidMount, componentWillUnmount,

 componentWillReceiveProps, componentDidUpdate) with useEffect

e.g.

const [items, setItems] = useState([]);

const [num, setNum] = useState(0);

1. compentDidMount

useEffect(()=>{

setItems(items);

}, [])   // Here empty array indicates don’t look for any updates

b.componentWillUnmount

useEffect(()=>{

return () => {console.log(‘unmounting the component’)}

},[])

c. componentDidUpdate/componentWillReceiveProps

This will get executed when your ‘num’ state variable and ‘id’ props will get updated.

useEffect(()=>{

if (!isEmpty(num))

{

console.log(‘num changed = ’,num);

setItems(items);

}

if(!isEmpty(props.id))

{

console.log(‘props.id changed = ’,props.id);

}

},[num, props.id])

• Use of useRef

const [num, setNum] = useState(0);

const prevNumRef = useRef();

useEffect(()=>{

prevNumRef.current = num;

})

const prevNum = prevNumRef.current;

return <h1>Current value : {num}, previous value = {prevNum}</h1>

Advantages

1.With React hooks, the component will be cleaner and easier to read (fewer lines of code). Hooks are easier to work with and to test.

2.It is easy to make code reusable. They don’t create another element in DOM like HOCs in React do.

3. useState – it allows to update different states with specific functions. The ability to move the state update logic as a separate hook.

Disadvantages

1.useEffect hook allows to merge three lifecycle methods such as componentDidMount, componentWillUnmount and componentDidUpdate into one and the issue with useEffect is the second parameters ,i.e. the array that we need to pass to define this behaviour. It is not explicit enough.

2.React Hooks are new additions to React. So to convert and test a complex class can be a time-consuming task initially .

3.Since it is relatively a new addition it may not be compatible with all third party libraries. But this is rapidly changing .

This is all about React Hooks in a nutshell. If you are looking to build any a mobile or web application using React technology, then please contact us.

Happy coding!