How to pass props to {this.props.children}

by

Cloning children with new props

You can use React.Children to iterate over the children, and then clone each element with new props (shallow merged) using React.cloneElement. For example:

const Child = ({ doSomething, value }) => (
  <button onClick={() => doSomething(value)}>Click Me</button>
);

function Parent({ children }) {
  function doSomething(value) {
    console.log("doSomething called by child with value:", value);
  }

  const childrenWithProps = React.Children.map(children, child => {
    // Checking isValidElement is the safe way and avoids a typescript
    // error too.
    if (React.isValidElement(child)) {
      return React.cloneElement(child, { doSomething });
    }
    return child;
  });

  return <div>{childrenWithProps}</div>
}

function App() {
  return (
    <Parent>
      <Child value={1} />
      <Child value={2} />
    </Parent>
  );
}

ReactDOM.render(<App />, document.getElementById("container"));
<script src="https://unpkg.com/react@17/umd/react.production.min.js"></script>
<script src="https://unpkg.com/react-dom@17/umd/react-dom.production.min.js"></script>
<div id="container"></div>

Calling children as a function

Alternatively, you can pass props to children with render props. In this approach, the children (which can be children or any other prop name) is a function which can accept any arguments you want to pass and returns the children:

const Child = ({ doSomething, value }) => (
  <button onClick={() => doSomething(value)}>Click Me</button>
);

function Parent({ children }) {
  function doSomething(value) {
    console.log("doSomething called by child with value:", value);
  }

  // Note that children is called as a function and we can pass args to it.
  return <div>{children(doSomething)}</div>
}

function App() {
  // doSomething is the arg we passed in Parent, which
  // we now pass through to Child.
  return (
    <Parent>
      {doSomething => (
        <React.Fragment>
          <Child doSomething={doSomething} value={1} />
          <Child doSomething={doSomething} value={2} />
        </React.Fragment>
      )}
    </Parent>
  );
}

ReactDOM.render(<App />, document.getElementById("container"));
<script src="https://unpkg.com/react@17/umd/react.production.min.js"></script>
<script src="https://unpkg.com/react-dom@17/umd/react-dom.production.min.js"></script>
<div id="container"></div>

Instead of <React.Fragment> or simply <> you can also return an array if you prefer.

Leave a Comment