How to handle state in React. – React Ecosystem – Medium

How to handle state in React. The missing FAQ.

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#Reactjs #javascript

  • Each one corresponding to the way you create the component: – // Using React.createClass – var Counter = React.createClass({ – getInitialState: function() { – return {counter: 0}; – }, – …});// Using ES6 classes – class Counter extends React.Component { – constructor(props) { – super(props); – this.state = {counter: 0};…
  • Let’s exemplify: – // Don’t duplicate data from props in state – // Antipatternclass Component extends React.Component { – constructor(props) { – super(props); – this.state = {message: props.message}; – } – – render() { – return div{this.state.message}/div; – } – }The problem with the above example is it will only…
  • You can do better just by avoiding this situation: – // Better exampleclass Component extends React.Component { – render() { – return div{this.props.message}/div; – } – }The same applies when you hold state based on props calculation: – // Don’t hold state based on props calculation – // Antipatternclass Component…
  • // Antipatternclass Component extends React.Component { – constructor(props) { – super(props); – this.state = {count: 0}; – } – – render() { – return div{this.state.count}/div; – } – – componentDidMount() { – const interval = setInterval(() = ( – this.setState({count: this.state.count + 1}) – ), 1000); this.setState({interval}); – } componentWillUnmount()…
  • Let’s experiment a little bit to see what happens: – class Component extends React.Component { – constructor(props) { – super(props); – this.state = {count: 0}; – this.onClick = this.onClick.bind(this); – } – – render() { – return div } – – onClick() { – this.setState({count: this.state.count + 1}); – }…

Recently there has been a lot of debate about how to manage the state in React. Some claim that setState() doesn’t work as you might expect. That you have to externalize the state using a Flux-like…
Continue reading “How to handle state in React. – React Ecosystem – Medium”

React Tutorial: A Comprehensive Guide to learning React.js in 2018

  • These components are defined either in pure JavaScript or they can be defined in what the React team calls “JSX”.
  • The reason the React team went with this approach is because, since the virtual DOM is a JavaScript representation of the actual DOM, React can keep track of the difference between the current virtual DOM(computed after some data changes), with the previous virtual DOM (computed befores some data changes).
  • In more layman’s terms, because manipulating the actual DOM is slow, React is able to minimize manipulations to the actual DOM by keeping track of a virtual DOM and only updating the real DOM when necessary and with only the necessary changes.
  • The process looks something like this, – – Some user event which changes the state of your app → Re-render virtual DOM -> Diff previous virtual DOM with new virtual DOM -> Only update real DOM with necessary changes.
  • Signal to notify our app some data has changed→ Re-render virtual DOM -> Diff previous virtual DOM with new virtual DOM -> Only update real DOM with necessary changes.

Continue reading “React Tutorial: A Comprehensive Guide to learning React.js in 2018”

A Comprehensive Guide to React.js in 2018

  • These components are defined either in pure JavaScript or they can be defined in what the React team calls “JSX”.
  • The reason the React team went with this approach is because, since the virtual DOM is a JavaScript representation of the actual DOM, React can keep track of the difference between the current virtual DOM(computed after some data changes), with the previous virtual DOM (computed befores some data changes).
  • In more layman’s terms, because manipulating the actual DOM is slow, React is able to minimize manipulations to the actual DOM by keeping track of a virtual DOM and only updating the real DOM when necessary and with only the necessary changes.
  • The process looks something like this, – – Some user event which changes the state of your app → Re-render virtual DOM -> Diff previous virtual DOM with new virtual DOM -> Only update real DOM with necessary changes.
  • Signal to notify our app some data has changed→ Re-render virtual DOM -> Diff previous virtual DOM with new virtual DOM -> Only update real DOM with necessary changes.

This is the original guide for learning to build apps with React.js. Recently upgraded to support React 16.3 and friends.
Continue reading “A Comprehensive Guide to React.js in 2018”

The Future of State in React

The Future of State in React -   . . . . #chstech #reactjs #javascript

  • React’s new Context API will be the go-to solution for sharing state simply™️.
  • In this post, I’ll describe Context by creating a simple theme-switching component: – – Since Context won’t be live until React 16.3, I’ll be using the polyfill.
  • Creating a Context instance is as simple as calling a function with a default value .
  • Context’s has less emphasis on global state than Redux and can be used to as little or as large a scale that you’d want: just like MobX.
  • In the following snippet, I set up a React Component that manages the state that our Provider will pass to those willing to consume it: – – Consumers must be descendants of its context’s Provider for it to access the value it wants.

Continue reading “The Future of State in React”

React Tutorial: A Comprehensive Guide to learning React.js in 2018

  • These components are defined either in pure JavaScript or they can be defined in what the React team calls “JSX”.
  • The reason the React team went with this approach is because, since the virtual DOM is a JavaScript representation of the actual DOM, React can keep track of the difference between the current virtual DOM(computed after some data changes), with the previous virtual DOM (computed befores some data changes).
  • In more layman’s terms, because manipulating the actual DOM is slow, React is able to minimize manipulations to the actual DOM by keeping track of a virtual DOM and only updating the real DOM when necessary and with only the necessary changes.
  • The process looks something like this, – – Some user event which changes the state of your app → Re-render virtual DOM -> Diff previous virtual DOM with new virtual DOM -> Only update real DOM with necessary changes.
  • Signal to notify our app some data has changed→ Re-render virtual DOM -> Diff previous virtual DOM with new virtual DOM -> Only update real DOM with necessary changes.

Continue reading “React Tutorial: A Comprehensive Guide to learning React.js in 2018”

Why’s React Native so promising?

Why is #ReactNative so promising? Read Valentin's blog post to find out!

  • React Native looks a lot like React: roughly the same syntax, classes, JSX, state, props… but React Native is a framework, which means you have more features than just rendering in React Native.
  • To do that, the Facebook team created a bunch of APIs to interact with the camera, the keyboard, the vibrations… – – One of the big advantages of using React Native is that, while the core app runs in a JavaScript Engine, it uses JSX to render native code.
  • You use classes, ES6, states and the like, with a few notable differences: – – Not much to say here except that Redux, the React developers’ favourite state management library, also works with React Native with absolutely no difference in the way you’ll dev.
  • Here’s an example of a small Menu component: – – This article is not about HOCs; just know they allow a greater flexibility around the way you compose your components and you can use them in React Native.
  • With React Native you can compose your styles and properties, combine them and then have them applied onto your component.

Continue reading “Why’s React Native so promising?”

The Future of State in React

The Future of #State in #reactjs   #javascript #developers

  • React’s new Context API will be the go-to solution for sharing state simply™️.
  • In this post, I’ll describe Context by creating a simple theme-switching component: – – Since Context won’t be live until React 16.3, I’ll be using the polyfill.
  • Creating a Context instance is as simple as calling a function with a default value .
  • Context’s has less emphasis on global state than Redux and can be used to as little or as large a scale that you’d want: just like MobX.
  • In the following snippet, I set up a React Component that manages the state that our Provider will pass to those willing to consume it: – – Consumers must be descendants of its context’s Provider for it to access the value it wants.

The days of relying on state-management libraries for non-local state are coming to a close. You wont need Redux anymore. Not even MobX. React’s new Context API will be the go-to solution for sharing state simply™️.
Continue reading “The Future of State in React”

Vue.js vs. React.js: Comparing Two JavaScript UI Component Libraries

  • At a time where large MVC (model-view-controller) frameworks were cutting edge, two-way data binding was considered a feature, and SSR was mostly used for static webpages, React reversed the trend, focusing on building applications from encapsulated view components, one-way data binding, and using SSR on dynamic web pages via the…
  • Dependency tracking gives Vue’s virtual DOM a slight edge over React out of the box, because it can selectively re-render the child components that are actually affected by a change in state by default — no additional coding required.
  • In React, JSX breaks with the convention of keeping JavaScript and HTML separate, by providing a declarative XML-like syntax that allows you to create self-contained UI components that encapsulate all the instructions required to render them within the view: – – The React code above will render into a simple…
  • Under the React umbrella, we have Flux, the application architecture pattern Facebook developed as a state management solution to avoid issues like the infamous phantom unseen message bug, and Redux, a framework agnostic library for providing a simplified implementation of the Flux pattern, which replaces MVC (model-view-controller).
  • Both Vue and React are cutting edge UI component libraries that make use of a virtual DOM, embrace the components based future of web development, support SSR, and Universal JavaScript.

In this article, we’ll explore some of the key differences between the React.js and Vue.js JavaScript libraries, and learn which might be the best fit for your next web project.
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React State vs Props explained – codeburst

  • Let me define a React component a plain javascript function side by side.class DummyComponent extends React.Component { render () { return divHey/div }}const DummyFunction = () = console.log(‘Hey’)We defined a React component named DummyComponent and returned a div containing text Hey similarly, we defined a function named DummyFunction and output…
  • Let’s take a look at State.React Component StateA state in React Component is its own local state, the state cannot be accessed and modified outside the component and can only be used inside the component which is very similar to, you already guessed it a function own local scope.
  • Let’s demonstrate this with an example.class DummyComponent extends React.Component { state = { name: ‘Manoj’ } render() { return divHello {this.state.name}/div; } }const DummyFunction = () = { let name = ‘Manoj’; console.log(`Hey ${name}`)}As you can see a component state can be compared to a function local scope.
  • Let’s take a look how we can use props in react.class DummyComponent extends React.Component { render() { return divHello {this.props.name}/div; } }// when using the componentDummyComponent name=”Manoj” /DummyComponent name=”Ajay” /We used one react component in multiple places here but with a different name.
  • Props, on the other hand,make components reusable by giving components the ability to receive data from the parent component in the form of props.We also get to know that React components are pretty similar to normal JS functions so from the next time keep this thing in mind 😉 .

Before jumping to state vs props we have to compare a React component with a javascript plain function. Let me define a React component & a plain javascript function side by side. We defined a React…
Continue reading “React State vs Props explained – codeburst”

The Pros and Cons of ReactJS for your Online Business

The Pros and Cons of ReactJS for your #OnlineBusiness via @janlgordon

  • With React, it is possible for webmasters and online business owners to develop large web-based applications that change data while reloading pages.
  • Webmasters can also use React together with other forms of frameworks or JavaScript libraries like Angular in MVC.
  • It makes it possible to reuse components that didn’t produce changes, and this makes programming more comfortable and precise for online business owners.
  • The great news for webmasters is that Google might still find the React component when just the client-side is rendered.
  • ReactJS is a great framework for online business.

This isn’t quite a ReactJS guide for the layman. But it is a useful for business owners, if only to glean enough to know how to talk with your techie
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