React-native-intersection-observer NPM

react-native-intersection-observer

React Native implementation of the Intersection Observer API to tell you when an element enters or leaves the viewport.

Installation

Install using Yarn:

yarn add react-native-intersection-observer

or NPM:

npm install react-native-intersection-observer --save

Usage

You can pass any component to the <InView />, and it will handle creating the wrapping View component. Add a handler to the onChange method, and control the state in your own component. Any extra props you add to <InView> will be passed to the View component, allowing you to set the style, etc.

import { IOScrollView, InView } from 'react-native-intersection-observer'

const Component = () => (
  <IOScrollView>
    <InView onChange={(inView: boolean) => console.log('Inview:', inView)}>
      <Text>Plain children are always rendered. Use onChange to monitor state.</Text>
    </InView>
  </IOScrollView>  
)

export default Component

API

IOScrollView Props

Name	Type	Default	Required	Description
rootMargin	{ top: number; left: number; right: number; bottom: number }	undefined	false	root margin

InView Props

The <InView /> component also accepts the following props:

Name	Type	Default	Required	Description
as	`ComponentType`	View	false	Render the wrapping element as this element. Defaults to `View`.
children	`ReactNode`		true	Children expects a plain child, to have the `<InView />` deal with the wrapping element.
triggerOnce	boolean	false	false	Only trigger this method once
onChange	`(inView: boolean) => void`		false	Call this function whenever the in view state changes. It will receive the `inView` boolean, alongside the current `IntersectionObserverEntry`.