Package Exports

@rooks/use-intersection-observer-ref

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Readme

@rooks/use-intersection-observer-ref

TitleCard

About

A hook to register an intersection observer listener

Installation

npm install --save @rooks/use-intersection-observer-ref

Importing the hook

import useIntersectionObserverRef from "@rooks/use-intersection-observer-ref"

Usage

function Demo() {
  const [isVisible, setIsVisible] = useState(false);
  const callback = entries => {
    if (entries && entries[0]) {
      setIsVisible(entries[0].isIntersecting);
    }
  };
  const [myRef] = useIntersectionObserverRef(callback);
  return (
    <>
      <div
        style={{
          position: "fixed",
          top: 0,
          right: 0
        }}
      >
        <h1>Is rectangle visible - {String(isVisible)}</h1>
      </div>
      <div style={{ height: 2000 }}></div>
      <div ref={myRef} style={{ height: 300, background: "red" }}></div>
      <div style={{ height: 2000 }}></div>
    </>
  );
  return null
}

render(<Demo/>)

Arguments

Argument	Type	Description	Default Value
callback	IntersectionObserverCallback	React ref whose boundingClientRect is to be found	undefined
options	IntersectionObserverInit	React ref whose boundingClientRect is to be found	`{ root: null,rootMargin: "0px 0px 0px 0px", threshold: [0, 1]}`

Return

Returns an array with the first element in the array being the callback ref for the React component/element that needs to be observed.

Return value	Type	Description	Default value
ref	CallbackRef	ref for the React component/element that needs to be observed.	null