Techniques for decomposing React components – DailyJS – Medium

Techniques for decomposing #ReactJS components:  by @Dvtng #JavaScript

  • Here are three techniques to get you started, from the simplest to most advanced.Split the render() methodThis is the most obvious technique to apply: when a component renders too many elements, splitting those elements into logical sub-components is an easy way to simplify.A common and quick way to split the render() method is to create additional “sub-render” methods on the same class:While this can have its place, it is not a true decomposition of the component itself.
  • As a bonus, when React’s new Fiber architecture arrives, the smaller units will allow it to perform incremental rendering more effectively.Templatize components by passing React elements as propsIf a component is becoming too complex due to multiple variations or configurations, consider turning the component into a simple “template” component with one or more open “slots”.
  • Utilise the ability of React to pass elements, not just data, as props, to create a flexible template component.Another component can then have the sole responsibility of figuring out what to fill the metadata and actions slots with.Keep in mind that in JSX, anything that’s between the opening and closing tags of a component is passed as the special children prop.
  • In the comments example, this would likely be the text of the comment itself.Extract common aspects into higher-order componentsComponents can often become polluted by cross-cutting concerns that aren’t directly related to its main purpose.Suppose you wanted to send analytics data whenever a link in a Document component is clicked.
  • The obvious solution might be to add code to Document’s componentDidMount and componentWillUnmount lifecycle methods, like so:There are a few problems with this:The component now has an extra concern that obscures its main purpose: displaying a document.If the component has additional logic in those lifecycle methods, the analytics code also becomes obscured.The analytics code is not reusable.Refactoring the component is made harder, as you’d have to work around the analytics code.Decomposition of aspects such as this one can be done using higher-order components (HOCs).

React components have a lot of power and flexibility. With so many tools at your disposal, it is incredibly easy for components to grow over time, become bloated and do too much. As with any other…
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A stronger (typed) React Apollo – Apollo GraphQL

A stronger (typed) React Apollo:  #ReactJS #GraphQL

  • Helping developers understand what they can use in their React components was our first priority when we set up flow types for Apollo.Let’s take for example a simple React component wrapped with the graphql HOC from React Apollo.
  • This component will display a hero from Star Wars and their friends with data returned from a GraphQL endpoint:The above code pulls some data from a GraphQL API using a query and includes lifecycle information, such as loading and error information.
  • We tell Flow what the shape of the result will look like from the server when the graphql enhancer wraps a component.
  • If you already are a user of Flow and have your data typed already, with a couple of imports and a single type addition, you can type any component that is wrapped with graphql!Currently Flow does not support the ES7 decorator syntax so you won’t be able to get all of the benefits of stronger type support if you are using decorators.
  • Let’s make a change to our initial component that converts it to use a prop called episode:We can define the props that our exported component will need (InputProps) and attach them to our enhancer using the second type generic of OperationComponent.

Static typing can be low-hanging fruit to improve your app. As data flows throughout the application, it is easy to forget its shape, and even for what it’s used. Although you could have unit tests…
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React + D3.js: Balancing Performance & Developer Experience

#ReactJS + D3.js: Balancing performance & developer experience  #JavaScript

  • The idea is still to use D3’s helpers and JSX to render SVG elements, except that now the elements rendered by React are rendered without attributes, and D3 is used to add their attributes.
  • Each of these methods can use typical D3 code to position, style, and transition elements.There are some caveats to this approach:As declared in the post introducing this idea, exit() transitions are not supported without bringing in React’s TransitionGroup.Since React does not keep track of attributes, we have to manually implement state comparison to detect when the component should update in order to call the update() method performing D3 transitions.
  • I believe this is due to the need to split the code according to the line of ownership between React and D3, instead of splitting it into logical units.Solution 3 — Feed D3 a fake DOM that renders to stateThis is the solution I found the most elegant so far, and it is what powers the demo at the beginning of this post.
  • That fake DOM is manipulated by D3 and then automatically rendered as React elements stored into the component’s state where React can pick up changes and kick-off an update, including lifecycle methods and reconciliation as you would expect.I found this approach elegant because both D3 and React are used without alienation.Except for feeding the faux DOM node to D3 instead of using a selector as you normally would, vanilla D3 code can be used.
  • Hence, you get to enjoy the typical render performance of React components.SVG elements are automatically transformed into React elements and are inspectable in the devtools.The implementation is compatible with server-side rendering, so you get isomorphic charts at no cost.Overall, this solution has restored my faith is having a great DX when using D3 visualizations in React components, while making the most out of React’s render performance.

Let’s put it out there, I love dashboards. I find the way they help you gain a rapid understanding out of complex information really interesting. I have written real-time data visualisations in the…
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Building an app with @reactjs? Accept payments with our new React components that help you quickly add @stripe! ⚛️🚀✨

  • React components that help you quickly add Stripe Elements to your React app.
  • Then, load Stripe.js in your application:

    In order for your application to have access to the Stripe object, let’s add to our root React App component:

    Next, when you’re building components for your checkout form, you’ll want to wrap the component around your .

  • All applications using must use the component, which sets up the Stripe context for a component tree.
  • uses the provider pattern (which is also adopted by tools like and ) to scope a Stripe context to a tree of components.
  • Components that need to initiate Source or Token creations (e.g. a checkout form component) can access via props of any component returned by the HOC factory.

react-stripe-elements – React components for Stripe.js and Stripe Elements
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React Components Explained – Manoj Singh Negi – Medium

“React Components Explained” by @manojnegiwd  #reactjs #NodeJS #javascript #coding

  • Something like thisimport React from ‘react’;class MyComponent extends React.Component { render () { return div This is a component /div }}class MyOtherComponent extends React.Component { render () { return ( div MyComponent / /div ) }}This way you are able to compose more complex and useful user interface for your users.
  • Component’s render method return JSX which then use to create real HTML output which will be rendered in the browser.The interesting Thing about render method is that it runs every time when your component State or Props updates.
  • Let me show you a exampleimport React from ‘react’;class MyComponent extends React.Component { constructor(props) { super(props); this.state = { name: “Manoj” }; } render () { return div My name is {} /div }}// if we render this component the output will beMy name is ManojIgnore the super(props) (out of the scope of this article) focus on this.state this is where our component state lives.
  • Let’s see an example.class MyComponent extends React.Component { constructor(props) { super(props); this.state = { name: “Manoj” }; this.changeName = this.changeName.bind(this); } changeName () { this.setState({ name: “Your Name” }); } render () { return div onClick={this.changeName} My name is {} /div }}In the above code we are telling our React component to call this.changeName whenever user clicks on the div.
  • You can run this code on jsFiddle here.PropsVisualise props as options that can be passed to a component to customize its functionality.For example, I have a heading component which renders a heading with subtitle.class MyHeading extends React.Component { render () { return div h1This is a heading/h1 pSubtitle/p /div }}If I will use this component it will always render same HTML, someting like this.This is a headingsubtitleIf we use our component in this way it is not of much use right ?

The simplest library I ever used in my life is React. As you know Reac hit is based upon component design. Everything in React is a component which makes it easy to reuse components frequently. You…
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