onbeforeunload not working inside react component

Question

I have a simple react-component where a user can edit data. As the values that may be changed could take some time I want to ask the user to confirm when leaving the page in

Answer 1

You'll need to call the method inside the lifecycle methods:

componentDidMount() {
  window.addEventListener("beforeunload", this.handleWindowBeforeUnload);
}

componentWillUnmount() {
  window.removeEventListener("beforeunload", this.handleWindowBeforeUnload);
}