@rooks/use-mutation-observer

@rooks/use-mutation-observer

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}