Package Exports

@rooks/use-mutation-observer

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (@rooks/use-mutation-observer) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

@rooks/use-mutation-observer

Note: Future updates to this package have moved to the main package rooks. All hooks now reside in a single package which you can install using

npm install rooks

yarn add rooks

Rooks is completely treeshakeable and if you use only 1 of the 50+ hooks in the package, only that hook will be bundled with your code. Your bundle will only contain the hooks that you need. Cheers!

TitleCard

About

Mutation Observer hook for React.

Installation

npm install --save @rooks/use-mutation-observer

Importing the hook

import useMutationObserver from "@rooks/use-mutation-observer"

Usage

function Demo() {
  const myRef = useRef();
  const [mutationCount, setMutationCount] = useState(0);
  const incrementMutationCount = () => {
    return setMutationCount(mutationCount + 1);
  };
  useMutationObserver(myRef, incrementMutationCount);
  const [XOffset, setXOffset] = useState(0);
  const [YOffset, setYOffset] = useState(300);
  return (
    <>
      <div
        style={{
          width: 300,
          background: "lightblue",
          padding: "10px",
          position: "absolute",
          left: XOffset,
          top: YOffset
        }}
        ref={myRef}
      >
        <div
          style={{
            resize: "both",
            overflow: "auto",
            background: "white",
            color: "blue",
            maxWidth: "100%"
          }}
        >
          <p>
            Resize this div as you see fit. To demonstrate that it also updates
            on child dom nodes resize
          </p>
        </div>
        <h2>Bounds</h2>
        <p>
          <button onClick={() => setXOffset(XOffset - 5)}> Move Left </button>
          <button onClick={() => setXOffset(XOffset + 5)}> Move Right </button>
        </p>
        <p>
          <button onClick={() => setYOffset(YOffset - 5)}> Move Up </button>
          <button onClick={() => setYOffset(YOffset + 5)}> Move Down </button>
        </p>
      </div>
      <div style={{ height: 500 }} onClick={incrementMutationCount}>
        <pre>Mutation count {mutationCount}</pre>
      </div>
    </>
  );
}

render(<Demo/>)

Arguments

Argument	Type	Description	Default value
ref	React ref	Ref which should be observed for Mutations	undefined
callback	function	Function which should be invoked on mutation. It is called with the `mutationList` and `observer`	undefined
config	object	Mutation Observer configuration	{attributes: true,,characterData: true,,subtree: true,,childList: true}