Updating state of a parentless component in React

amd-medium-parent-state-update-2.jsx

// DeeplyNestedChild.jsx
class DeeplyNestedChild extends React.Component {
    constructor(props) {
        super(props);
    }
    updateTopMostParent() {
        // Call this method with the state value to update
        window.updateTopMostParent(someValue); 
    }
    render() {
        return (
            <button 
                type="button" 
                 // Method to update the topmost parent
                onClick={ this.updateTopMostParent.bind(this) }
            >
            Update TopMost Parent
            </button>
        );  
    }
}

// Parent.jsx
class Parent extends React.Component {
    constructor(props) {
        super(props);
        this.state = {
            shown: true
        };
    }
    render() {
        return (
            <Child>
                <AnotherChild>
                    <DeeplyNestedChild />
                </AnotherChild>
            </Child>
        );
    }
}

 // Store reference of topmost parent component
const TopMostParent = ReactDOM.render(<Parent />, document.getElementById('root'));

window.updateTopMostParent = (someValue) => {
    // Update state of topmost parent when this method is called 
    TopMostParent.setState({ someStateVariable: someValue }); 
};