Container Components and Stateless Functional Components in React – Zsolt Nagy

  • Let’s introduce functional components:

    has become a function with a argument, returning the return value of the method of the original implementation.

  • Implications of the structure of stateless functional components:

    In the introduction, I mentioned that stateless functional components come with performance benefits.

  • Typically, container components have the following properties:

    The rule of thumb for choosing the appropriate syntax for React components is the following:

    then it is advised to use stateless functional components.

  • Let’s put theory into practice, and transform all the stateless component in our chat application into functional components.
  • Reviewing the conditions for modeling a component with a function, we can see that there is absolutely nothing preventing us from creating a functional equivalent of the class.

We will now introduce another way to define simple components. You will not only write less code, but you will also benefit from performance optimizations done by React. Let’s introduce functional components:
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React Fundamentals with Wes Bos Tickets, Fri, Sep 8, 2017 at 9:00 AM

  • This workshop is aimed at understanding the fundamentals of React.
  • Throughout the day, participants will work to build an application by incrementally learning each fundamental concept in React.
  • By taking the time to implement it into an application, participants will get a hands-on approach to understanding why and how React works.
  • Refunds for HackerYou workshops will only be given if we are notified 7 days prior to the event.

Eventbrite – HackerYou presents React Fundamentals with Wes Bos – Friday, September 8, 2017 at HackerYou, Toronto, ON. Find event and ticket information.
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Simple tutorial to understand props vs state in React.js by @jjude

Simple tutorial to understand #props vs #state in #ReactJS - @jjude

  • Like parameters in functions, you can pass properties into react.js component.
  • If you want to understand the basics of React.js component, read Create React.js component with Typescript.
  • The property will be an input from the invoking component with the inital value for the Timer.
  • Let us see how to invoke this Timer component with an initial value.
  • Whenver a component calls , React.js calls its corresponding function.

Use props to send information to a component. Use state to manage information created and updated by a component.
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8 things to learn in React before using Redux

  • A component can manage a whole lot of state, pass it down as props to its child components and pass a couple of functions along the way to enable child components to alter the state in the parent component again.
  • Component A is the only component that manages local state but passes it down to its child components as props.
  • In addition, it passes down the necessary functions to enable B and C to alter its own state in A.

    Now, half of the local state of component A is consumed as props by component C but not by component B.

  • When you lift the local state management down to component C, all the necessary props don’t need to traverse down the whole component tree.
  • When a library such as Redux “connects” its state managements layer with React’s view layer, you will often run into a higher order component that takes care of it (connect HOC in react-redux).

Facts about React that should be known before using Redux (or MobX). Most important: Learn React first, then opt-in Redux…
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Extracting Logic from React Components

Extracting Logic from #ReactJS Components:  by @Jack_Franklin #Javascript

  • Right now to test formatting of amounts I have to create and mount a React component, but I should be able to just call that function and check the result.
  • Let’s create which will house the function that is currently in our component.
  • To test this, we can replace the body of ’s so that it just calls the new function from our module:

    Notice that I’ve still left the function defined on ; when pulling code apart like this you should do it in small steps; doing it like this decreases the chance of inadvertently breaking the code and also makes it easier to retrace your steps if something does go wrong.

  • Sure, the function is very straightforward for now, but as it grows we can now test it very easily without any need to fire up a React component to do so.
  • By looking through our components and finding standalone functions that we can pull out, we’ve greatly simplified our component whilst increasing our test coverage and clarity of our application greatly.

In the previous screencast we took a React component that was doing too much and refactored it, splitting it into two components that are easier to maintain, use and test. Although I’d recommend watching that video first, you don’t need to have watched it to read this blog post. You can find all the code on GitHub if you’d like to run it locally.
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Beginners Guide into ReactJS

  • See React as HTML inside Javascript which brought about JSX(Javascript XML) we’ll discuss more on that later.
  • A React component is a single object that not only outputs HTML like a traditional template would, but also includes all the code needed to control that output.
  • As you can see, the component approach means that both HTML and JavaScript code live in the same file.
  • In React, mutable state is typically kept in the state property of components, and only updated with , They are referred to has

    Let’s quickly go through the below code.

  • The render method consist of a form element that has an input field and also a submit button below, The input field has the onChange function that takes in , this method takes in as a parameter which happens to be the DOM event handler, and gets the result from , is one of the component API methods which is use to update state value, with this as a user types into the input field, the value will be updated in state.

Dive into React with this Quick Start Guide. Differences between Props and State
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Intro to React – Christopher Hague – Medium

Intro to React  #learning #react #javascript #programming #learningtocode #reactjs

  • Here is another representation of how we can conceptualize our component hierarchy:- Application – Search Bar – Product Table – Category – ProductThe Trickle Down EffectHow does our application use each of the components to interact with one another?
  • In the same way that functions rely on arguments to operate on and manipulate data, components rely on props that are given as a they being declared.Using the example from above, it becomes easier to conceptualize how the Product and Category components are rendering the appropriate information onto the screen.
  • When the Product Table component is declared within the Application component, the Application will pass down this information related to all of the products to the Product Table as props.
  • As such, the Search Bar component will inherit a set of functions that define how the products in the API will be filtered based on the user input.The Category and Product components will then rely on the props passed down from Product Table to render the list of items, using the Search Bar component to filter the products based on the search terms and render only those products to the screen.
  • Conversely, if the search bar is empty then each product in the collection will be rendered.Divide and ConquerNow that we have some idea of how we want each of our components to function, let’s sketch each of them out below to get some idea of how the code for the app might look:class Category extends React.Component { // renders categories}class Product extends React.Component { // renders products}class ProductTable extends React.Component { // declares a Category and Product component, passing props to each of them Category category={product.category} key={product.category} / Product product={product} key={product.name} / // renders Category, Product}class SearchBar extends React.Component { // renders SearchBar // filters based on search terms}class Application extends React.Component { // renders SearchBar and ProductTable components, passing props to each of them SearchBar / ProductTable products={this.props.products} /}Now that we have all of our components defined, rendering the application to the screen becomes as simple as using the ReactDOM.render function and passing the Application component to it.ReactDOM.render( Application products={PRODUCTS} /,

React is a declarative, component-based JavaScript library used for building user interfaces. It was created by Facebook employee Jordan Walke and was first deployed on Facebook and Instagram in 2011…
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