Evolving Patterns in React

  • A good way of bypassing this is to use props destructuring together with JSX spread , as you can see here: – – So now, you can change the props needed for and be sure that those props are not referenced in multiple components.
  • If you are using Redux, you will recognize that the function is a HOC — takes your component and adds a bunch of props to it.
  • Let’s implement a basic HOC that can add props to existing components.
  • Each HOC will introduce an additional React Component in your DOM/vDOM structure.
  • Render props can be used in situations where you need some reusable logic inside the component and you don’t want to wrap your component in a HOC.

Let’s take a closer look at some of the patterns that are emerging in the React ecosystem. These patterns improve readability,…
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React State From the Ground Up

#ReactJS State From the Ground Up #JavaScript

  • State, in React, is a plain JavaScript object that allows you keep track of a component’s data.
  • The initial state of the App component has been set to a state object which contains the key username, and its value using .
  • Initializing a component state can get as complex as what you can see here: – – An initialized state can be accessed in the method, as I did above.
  • Your component should look like this; – – A state can be passed as props from a parent to the child component.
  • This method will be used to update the state of the component.

As you begin to learn React, you will be faced with understanding what state is. State is hugely important in React, and perhaps a big reason you’ve looked into using React in the first place. Let’s take a stab at understanding what state is and how it works. What is State? State, in React, is a plain JavaScript
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5 Reasons Why I Love React Native – codeburst

“5 Reasons Why I Love #ReactNative” — @AdhithiRavi

  • If you know Javascript, it is easy to learn.I started writing my first React Native app, with zero prior experience in mobile application development.
  • Web developers can leverage their knowledge in Javascript to write React Native apps.
  • Don’t ever waste time recompiling.This is one of my most favorite aspects of developing React Native Apps.
  • Android Date Picker— Underlying Native WidgetiOS Date Picker — Underlying Native WidgetThese are some aspects of React Native that makes the developer’s life much easier and we don’t need to reinvent the wheel here.
  • With React Native build Android, iOS and Windows Apps all in Javascript.5.

React Native is very popular these days, and thousands of apps are already built using React Native. Big names like Facebook, AirBnB, Uber, and many other companies have embraced React Native and are…
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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.

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How to NOT React: Common Anti-Patterns and Gotchas in React

Awesome post on #reactjs common problems and solutions

  • Democlass app extends Component { – constructor(props) { – super(props); – this.state = { – name: ” – }; – this.updateValue = this.updateValue.bind(this); – }updateValue(evt) { – this.setState({ – name: evt.target.value – }); – }render() { – return ( – form – input onChange={this.updateValue} value={this.state.name} / – /form – )…
  • Now you can write components like this — – class App extends Component { – constructor(props) { – super(props); – this.state = { – name: ” – };// Look ma!
  • updateValue = (evt) = { – this.setState({ – name: evt.target.value – }); – }render() { – return ( – form – input onChange={this.updateValue} value={this.state.name} / – /form – ) – } – }Read More —2.
  • However, using certain set of values such as array indexes may break your application or render wrong index) = – Display – {…element} – key={index} – / – ) – }ProblemsWhen children have keys, React uses the key to match children in the original tree with children in the subsequent…
  • The docs also mention this — – Because this.props and this.state may be updated asynchronously, you should not rely on their values for calculating the next state.Another problem is when you have multiple setState calls in a single function, as shown above on line 16 and 20.

What is an anti-pattern? Anti-patterns are certain patterns in software development that are considered bad programming practices. The same pattern may have been considered correct at one point in…
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donavon/react-af – Next #reactjs features, today

donavon/react-af - Next #reactjs features, today

  • One problem that React component library developers face is that they don’t control the version of React that they run on — this is controlled by the consuming application.
  • emulates newer features of React on older versions, allowing developers to concentrate on the business problem and not the environment.
  • You can now code your library components as though they are running on a modern React (not all features supported… yet), even though your code may be running on an older version.
  • Here are the modern React features that you can use, even if yur code is running on older version of React 15 or React 16.
  • Starting with React 16.2, there is a new component that allows you to return multiple children.

GitHub is where people build software. More than 27 million people use GitHub to discover, fork, and contribute to over 80 million projects.
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React Authentication in Depth – Hacker Noon

React Authentication in Depth:  #React #Reactjs #ReactNative #JavaScript

  • First, let’s go ahead and create our React project using Create React App, and change into the new project’s directory: – create-react-app react-auth – cd react-authNext, let’s install React Router and Glamor using either npm or yarn: – yarn add react-router-dom glamoror – npm i react-router-dom glamor –saveAdding the identity providerYou…
  • Next we’ll add user-signin (Amazon Cognito) and deploy the new configuration: – awsmobile user-signin enable – awsmobile pushawsmobile user-signin enable will enable Amazon Cognito in our project with default settings, including 2 factor authentication with SMS (we will add TOTP later).
  • If you would like more control over how your authentication provider is created, you can either pass the -p flag to specify a more detailed configuration (awsmobile user-signin enable -p), or you can go to Amazon Cognito to directly create and configure the service in the console.To see a more…
  • : 2 factor authentication for new user sign up – confirmSignUp(username: string, authenticationCode: string) – signIn — signs in an existing user – signIn(username: string, password: 2 factor authentication for user sign in – confirmSignIn(user: object, authenticationCode: string) – Now, let’s wire this up!
  • When the user signs up using the signUp method, they will receive an authorization code via SMS, and will need to input this value into the form and we will then confirm that this code is correct by calling confirmSignUp: – – Let’s now create the inputs, buttons, and the…

How to do implement world 2 factor authentication (both SMS and TOTP) using React, React Router, and Amazon Cognito In this post, we’ll walk through how to implement real world user sign up and sign…
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