@alessiofrittoli/react-components

React Components 🧩

TypeScript React Components

Table of Contents

• Getting started
• API Reference
  • High Order Components
    • <InView />
    • <Stack />
    • WithGenerator
• Development
  • Install depenendencies
  • Build the source code
  • ESLint
  • Jest
• Contributing
• Security
• Credits

---

Getting started

Run the following command to start using react-components in your projects:

npm i @alessiofrittoli/react-components

or using pnpm

pnpm i @alessiofrittoli/react-components

---

API Reference

Components

High Order Components

<InView />

A React higher-order component that renders its children based on their visibility within the viewport.

This Component uses useInView hook under-the-hood so it may worth to take a look at the useInView API Reference for a deep understanding on how it actually works.

Component Props

Property	Type	Default	Description
mountInView	boolean	true	Indicates whether to mount/unmount children when in view.
children	FunctionChildren<[ result: UseInViewReturnType ]>	-	A React.ReactNode or a callable function that returns a React.ReactNode.
root	Element|Document|false|null	-	(Optional) Identifies the Element or Document whose bounds are treated as the bounding box of the viewport for the Element which is the observer's target.
margin	MarginType	-	(Optional) A string, formatted similarly to the CSS margin property's value, which contains offsets for one or more sides of the root's bounding box.
amount	'all'|'some'|number|number[]	-	(Optional) The intersecting target thresholds.
			Threshold can be set to:
			- all - 1 will be used.
			- some - 0.5 will be used.
			- number
			- number[]
once	boolean	-	(Optional) By setting this to true the observer will be disconnected after the target Element enters the viewport.
initial	boolean	-	(Optional) Initial value. This value is used while server rendering then will be updated in the client based on target visibility. Default: false.
enable	boolean	-	(Optional) Defines the initial observation activity. Use the returned setEnabled to update this state. Default: true.
onIntersect	OnIntersectStateHandler	-	(Optional) A custom callback executed when target element's visibility has crossed one or more thresholds.
			This callback is awaited before any state update.
			If an error is thrown the React State update won't be fired.
			⚠️ Wrap your callback with useCallback to avoid unnecessary IntersectionObserver recreation.
onEnter	OnIntersectHandler	-	(Optional) A custom callback executed when target element is entering the viewport.
			This callback is awaited before any state update.
			If an error is thrown the React State update won't be fired.
			⚠️ Wrap your callback with useCallback to avoid unnecessary IntersectionObserver recreation.
onExit	OnIntersectHandler	-	(Optional) A custom callback executed when target element is exiting the viewport.
			This callback is awaited before any state update.
			If an error is thrown the React State update won't be fired.
			⚠️ Wrap your callback with useCallback to avoid unnecessary IntersectionObserver recreation.
...	React.ComponentProps<'div'>	-	(Optional) Props added to the internal observed HTMLDivElement.

---

Usage

Basic usage

'use client'

// ClientComponent.tsx
const ClientComponent: React.FC = () => {

  useEffect( () => {
    console.log( 'ClientComponent entered viewport.' )
    return () => {
      console.log( 'ClientComponent exited viewport.' )
    }
  }, [] )

  return (
    <div>ClientComponent</div>
  )

}

// ServerComponent.tsx
const ServerComponent: React.FC = () => (
  <InView>
    <ClientComponent />
  </InView>
)

---

Server-Render initial value

By default <InView /> mounts/unmounts its children based on intersection within the viewport. If your component renders important SEO informations, mounting/unmounting yout component only when is in the viewport may not the best option since the rendered content won't be part of the server-rendered web page.

To ensure your content is delivered in the server-rendered web page, you may want to set the initial prop to true.

const Component: React.FC = () => (
  <InView initial>
    <h1>I&apos;ll be in the source page!</h1>
  </InView>
)

Alternatively you can set the mountInView prop to false, which prevents the mount/unmount life-cycle, and then pass a callable function as children.

By passing a callable function as children you'll earn access to the useInView result data.

const Component: React.FC = () => (
  <InView mountInView={ false }>
    { ( { inView, enabled, isExiting, setEnabled, setInView, observer } ) => (
      <h1 style={ {
        opacity     : inView ? 1 : 0,
        transition  : 'opacity 1s ease',
      } }>I&apos;ll be in the source page!</h1>
    ) }
  </InView>
)

---

<Stack />

Easily stack components avoiding creating a big Component stack pyramid.

Component Props

Property	Type	Description
components	StackComponent[]	An Array of Components or Component and props. The Component must accept and return children.
children	React.ReactNode	(Optional) The Component children.

---

Usage

Basic usage

import { Stack } from '@alessiofrittoli/react-components'

export const ProviderExample: React.FC<React.PropsWithChildren> = ( { children } ) => {
  // ...
  return (
    <div>{ children }</div>
  )
}

export const AppProviders: React.FC<React.PropsWithChildren> = ( { children } ) => (
  <Stack components={ [
    ProviderExample,
    AppProvider1,
    AppProvider2,
    AppProvider3,
    // ...
  ] }>{ children }</Stack>
)

---

Component with props

Use StackComponent<typeof ComponentReference> to add type safety to the passed props.

import { Stack, type StackComponent } from '@alessiofrittoli/react-components'

type ProviderExampleProps = React.PropsWithChildren<{
  /** Example required prop */
  className: string
}>


export const ProviderExample: React.FC<React.PropsWithChildren> = (
  { className, children }
) => (
  <div className={ className }>{ children }</div>
)

export const AppProviders: React.FC<React.PropsWithChildren> = ( { children } ) => (
  <Stack components={ [
    [ ProviderExample, { className: 'some-class-name' } ] as StackComponent<typeof ProviderExample>,
    AppProvider1,
    AppProvider2,
    AppProvider3,
    // ...
  ] }>{ children }</Stack>
)

---

WithGenerator

Transform your generator function into a React.js Component.

Type Parameters

Parameter	Default	Description
T	unknown	Component types.

---

Parameters

Parameter	Type	Description
fn	( props: T ) => AsyncGenerator<React.ReactNode, React.ReactNode, React.ReactNode>	The async generator function.

---

Usage

Stream Content from a React Component

import { WithGenerator } from '@alessiofrittoli/react-components'

interface StepProps
{
  someProp: string
}

export const Steps = WithGenerator<StepProps>(
  async function* ( { someProp } )
  {
    let i = 0

    yield <h1>Step { ++i } - { someProp }</h1>

    // simulate an async task by awaiting a void Promise
    await new Promise<void>( resolve => setTimeout( resolve, 2000 ) )

    yield <h1>Step { ++i } - { someProp }</h1>

    // simulate an async task by awaiting a void Promise
    await new Promise<void>( resolve => setTimeout( resolve, 2000 ) )

    return <h1>Step { ++i } - { someProp } - Stream finished</h1>
  }
)

---

Development

Install depenendencies

npm install

or using pnpm

pnpm i

Build the source code

Run the following command to test and build code for distribution.

pnpm build

ESLint

warnings / errors check.

pnpm lint

Jest

Run all the defined test suites by running the following:

# Run tests and watch file changes.
pnpm test:watch

# Run tests in a CI environment.
pnpm test:ci

• See package.json file scripts for more info.

Run tests with coverage.

An HTTP server is then started to serve coverage files from ./coverage folder.

⚠️ You may see a blank page the first time you run this command. Simply refresh the browser to see the updates.

test:coverage:serve

---

Contributing

Contributions are truly welcome!

Please refer to the Contributing Doc for more information on how to start contributing to this project.

Help keep this project up to date with GitHub Sponsor.

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Security

If you believe you have found a security vulnerability, we encourage you to responsibly disclose this and NOT open a public issue. We will investigate all legitimate reports. Email [e-mail] to disclose any security vulnerabilities.

Made with ☕

Alessio Frittoli https://alessiofrittoli.it | [e-mail]