Learning React.js: Getting Started and Concepts ― Scotch

  • — React Code Goes Here — – – /script – /body – /html – In React, components mount to an element, so in this example we can use the div myDiv as it’s parent container.
  • These attributes are available in our component as this.props and can be used in our render method to render dynamic data: – var MyComponent = React.createClass({ – render: function(){ – return ( – h1Hello, {this.props.name}!
  • Below, see how we can set our component’s state: – var MyComponent = React.createClass({ – getInitialState: function(){ – return { – count: 5 – } – }, – render: function(){ – return ( – h1{this.state.count}/h1 – ) – } – }); – – Events – React also has a built…
  • Lets make our count increment below using events: – /** @jsx React.DOM */ – – var Counter = React.createClass({ – incrementCount: function(){ – this.setState({ – count: this.state.count + 1 – }); – }, – getInitialState: function(){ – return { – count: 0 – } – }, – render: function(){ -…
  • == -1; – }); – this.setState({items: updatedList}); – }, – getInitialState: function(){ – return { – initialItems: [ – “Apples”, – “Broccoli”, – “Chicken”, – “Duck”, – “Eggs”, – “Fish”, – “Granola”, – “Hash Browns” – ], – items: [] – } – }, – componentWillMount: function(){ – this.setState({items: this.state.initialItems})…

Today we are going to kick off the first installment in a new series of tutorials, Learning React, that will focus on becoming proficient and effective with Facebook’s React library. Before we start building anything meaningful, its important that we cover some base concepts first, so lets get this party started.
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Microservices with Docker, Flask, and React

  • To connect the client to the server, add a method to the class: – – We’ll use Axios to manage the AJAX call: – – You should now have: – – To connect this to Flask, open a new terminal window, navigate to the flask-microservices-users, activate the virtual environment, and…
  • Kill the Create React App server, and then run: – – We still need to call the method, which we can do in the : – – Run the server – via – and then within Chrome DevTools, open the JavaScript Console.
  • What would happen if the AJAX request took longer than expected and the component was mounted before it was complete?
  • Finally, update the method to display the data returned from the AJAX call to the end user: – – Let’s create a new component for the users list.
  • Add a new file to that folder called UsersList.jsx: – – Why did we use a functional component here rather than a class-based component?

If you’re new to React, review the Quick Start and the excellent Why did we build React? blog post. You may also want to step through the Intro to React tutorial to learn more about Babel and Webpack.
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I wish I knew these before diving into React – OpsGenie Engineering

  • By default, setState triggers a re-renderThe default behavior of React is to re-render on every state change, and most of the time it is okay to rely on this.
  • However, re-rendering unnecessarily wastes cycles which is not a good practice.Each component has a method called shouldComponentUpdate and it is called everytime you change state or pass new props from the parent component.
  • We can simply divide lifecycle into three parts:Mounting: an instance of the component is being created and inserted into the DOM.Updating: component is being re-rendered, can be caused by changes of props or state.Unmounting: component is being removed from the DOM.It is very important to understand how these methods work….
  • Compare this.props with nextProps and if there is a significant change, act on it.Two important notes here:React may call componentWillReceiveProps even if the props have not changed, so comparing this.props and nextProps is is invoked before a mounted component receives new props, this means React doesn’t call componentWillReceiveProps with initial…
  • Use React Developer ToolsReact Developer Tools lets you inspect the React component hierarchy, components’ props and state.

At OpsGenie, we had a deep dive into React for our Badges project. I learned many new things & made many mistakes. These are the things that really helped me.
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How to use React Lifecycle Methods » Andreas Reiterer

How to use #ReactJS Lifecycle Methods:  by @a_reiterer #JavaScript #Code

  • React components have several “lifecycle methods” that allow us to execute actions (e.g.: fetching data from a server) at particular times.
  • There are three particular stages in the lifecycle of a component, that are important for our lifecycle methods, which I will explain: – – When React creates an instance of a component and inserts it into the DOM (mounting), the following methods are called: – – If props or state…
  • That process is called unmounting and means that the following method is called: – – I hope I could give you a short overview of the life of a React component and the calling order of lifecycle methods.
  • Some people suggest to use it for doing some configuration of the root component that you can only do at runtime (e.g.: setting up a Firebase connection) – – Whenever this method is called, React has already rendered our component and put it into the DOM.
  • This means, it could be possible that the method returns false but React still decides to re-render the component.

Use React lifecycle methods to perform actions on mount, update and unmount of a component. Learn more about e.g. componentDidMount and when to use it
Continue reading “How to use React Lifecycle Methods » Andreas Reiterer”

How to use React Lifecycle Methods » Andreas Reiterer

  • React components have several “lifecycle methods” that allow us to execute actions (e.g.: fetching data from a server) at particular times.
  • There are three particular stages in the lifecycle of a component, that are important for our lifecycle methods, which I will explain: – – When React creates an instance of a component and inserts it into the DOM (mounting), the following methods are called: – – If props or state…
  • That process is called unmounting and means that the following method is called: – – I hope I could give you a short overview of the life of a React component and the calling order of lifecycle methods.
  • Some people suggest to use it for doing some configuration of the root component that you can only do at runtime (e.g.: setting up a Firebase connection) – – Whenever this method is called, React has already rendered our component and put it into the DOM.
  • This means, it could be possible that the method returns false but React still decides to re-render the component.

Use React lifecycle methods to perform actions on mount, update and unmount of a component. Learn more about e.g. componentDidMount and when to use it
Continue reading “How to use React Lifecycle Methods » Andreas Reiterer”

How to use React Lifecycle Methods » Andreas Reiterer

  • React components have several “lifecycle methods” that allow us to execute actions (e.g.: fetching data from a server) at particular times.
  • When React creates an instance of a component and inserts it into the DOM (mounting), the following methods are called:

    If props or state of a component are changed for whatever reason, an update of the component is performed.

  • That process is called unmounting and means that the following method is called:

    I hope I could give you a short overview of the life of a React component and the calling order of lifecycle methods.

  • Some people suggest to use it for doing some configuration of the root component that you can only do at runtime (e.g.: setting up a Firebase connection)

    Whenever this method is called, React has already rendered our component and put it into the DOM.

  • This means, it could be possible that the method returns false but React still decides to re-render the component.

Use React lifecycle methods to perform actions on mount, update and unmount of a component. Learn more about e.g. componentDidMount and when to use it
Continue reading “How to use React Lifecycle Methods » Andreas Reiterer”

Ch 10 “React Native” is new to React in Action @ManningBooks @MarkTheThomas #react

Ch 10

  • React is an open source JavaScript framework that lets you quickly create user interfaces for web applications.
  • It also utilizes a component-focused design, so you can build large, robust web applications that scale well with users and developers.
  • Reasoning about an interface or application written with React ends up being much easier because it decreases overall complexity for developers working with it.
  • Large and small companies alike are using React for highly-visible, high-impact applications including Facebook.com, Netflix.com, and Airbnb.com.
  • “An up-to-date and very comprehensive book on React, not only limited to React itself but also discusses how it can be integrated with other tools and frameworks.”

React is an open source JavaScript framework that lets you quickly create user interfaces for web applications. This highly-performant tool implements a one-way data flow model, which means communication is much more top-down than side-to- side. It also utilizes a component-focused design, so you can build large, robust web applications that scale well with users and developers. Reasoning about an interface or application written with React ends up being much easier because it decreases overall complexity for developers working with it. Large and small companies alike are using React for highly-visible, high-impact applications including Facebook.com, Netflix.com, and Airbnb.com.
Continue reading “Ch 10 “React Native” is new to React in Action @ManningBooks @MarkTheThomas #react”

#React in Action teaches you to use the #reactjs framework #JavaScript @MarkTheThomas

#React in Action teaches you to use the #reactjs framework  #JavaScript @MarkTheThomas

  • Reasoning about an interface or application written with React ends up being much easier because it decreases overall complexity for developers working with it.
  • Large and small companies alike are using React for highly-visible, high-impact applications including Facebook.com, Netflix.com, and Airbnb.com.
  • React in Action introduces front-end developers to the React framework and related tools.
  • In the second section, you’ll explore the different ways that data works in React as well as learning more about components.
  • In the last section, you’ll explore React application architecture with Redux, server-side rendering, and even dabble in React Native.

React is an open source JavaScript framework that lets you quickly create user interfaces for web applications. This highly-performant tool implements a one-way data flow model, which means communication is much more top-down than side-to- side. It also utilizes a component-focused design, so you can build large, robust web applications that scale well with users and developers. Reasoning about an interface or application written with React ends up being much easier because it decreases overall complexity for developers working with it. Large and small companies alike are using React for highly-visible, high-impact applications including Facebook.com, Netflix.com, and Airbnb.com.
Continue reading “#React in Action teaches you to use the #reactjs framework #JavaScript @MarkTheThomas”

React.js best practices and conventions

An opinionated guide to #ReactJS best practices and conventions:  #JavaScript

  • The following guidelines mostly focus on component structure and JSX.
  • However, by following a few general guidelines for handling JSX in components, it’s far more readable and not such an eyesore.
  • No matter how few elements are being returned, I choose to write any JSX which contains nested elements across multiple lines with indentation to enhance readability, i.e:

    Furthermore, while the parenthesis are not technically required with a single line JSX statement, I still use them for the sake of consistency (and because unrestrained elements floating about in my JS makes my left eye twitch uncontrollably).

  • These guidelines are by no means authoritative or exhaustive, but I feel they are a good starting point for organising and standardising React components and some of the more common use cases I encounter.
  • Hopefully these guidelines provide a useful starting point for organising your React components.

An opinionated set of React.js best practices to make components more readable, more robust and easily maintainable.
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How to avoid refactoring in your first React.js application

How to avoid refactoring in your first #ReactJS app:

  • In the short blog post I will try to point out some pitfalls, which you should take care of if you want to avoid refactoring in your first React.js application.
  • A common pattern is to create several stateless components that just render data, and have a stateful component above them in the hierarchy that passes its state to its children via props.
  • I don’t see any reasons why not using ES6.
  • If we want to change the data of our big grid component, we have to re-initialize our grid as a jQuery object in React using the componentDidUpdate method.
  • Let’s imagine we need a big grid component, which does some complex things with cells.

Popularity of React.js is growing pretty fast and it seems like React became a compact and beautiful way of how to develop your applications. I have worked on a side project and felt like it is right time to try React. During development of my first project in React I had to do several refactorings. In this short blog post I will try to point out some pitfalls, which you should take care of if you want to avoid refactoring in your first React.js application.
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