React: Open Modal from a different component - reactjs

Question

I have a Modal component in the Main.js app and I want to trigger it from a different component (in this case Homepage, but I have one component for each page).
I don´t know how to pass a component to be rendered inside the modal.
If it helps I´m using Context API.
App.js
const App = () => {
return (
<div>this is the main app</div>
<Modal />
)
}
ReactDOM.render(<App />, document.getElementById('root'))
Modal.js
class Modal extends Component {
constructor(props) {
super(props)
this.state = {
'open': false
}
}
componentWillReceiveProps(nextProps) {
this.setState({open: nextProps.open})
}
render() {
if (!this.state.open) {
return false
}
return(
<div className="modal">
{this.props.children}
</div>
)
}
}
export default Modal
Homepage.js
class Homepage extends Component {
constructor(props) {
super(props)
this.handleOpenModal = this.handleOpenModal.bind(this)
}
handleOpenModal() {
// here I want to open the modal and pass the <ModalContent /> component
// basically call the <Modal open="true"> from the Main component
}
render() {
return(
<div className="homepage">
<button onClick={this.handleOpenModal}>open the modal</button>
</div>
)
}
}
const ModalContent = () => {
return(
<div>this is the content I want to render inside the modal</div>
)
}
thank you.

Answer 1

I strongly recommend using something like react-modal (npm). It allows you to keep modal content right next to the trigger. It does this by appending a "portal" high up in the DOM and handles appending the content to is.
Your example may look like the following:
import Modal from 'react-modal';
class Homepage extends Component {
constructor(props) {
super(props)
this.state = { modalOpen: false };
this.handleOpenModal = this.handleOpenModal.bind(this)
}
handleOpenModal() {
this.setState({ modalOpen: true });
}
render() {
return(
<div className="homepage">
<button onClick={this.handleOpenModal}>open the modal</button>
<Modal open={this.state.modalOpen}>
<ModalContent />
</Modal>
</div>
)
}
}
const ModalContent = () => {
return(
<div>this is the content I want to render inside the modal</div>
)
}