React ~ Stuff - rohit120582sharma/Documentation GitHub Wiki

Returning null from setState in React 16

React 16 lets you decide whether state gets updated via .setState to prevent unnecessary DOM updates. Calling .setState with null no longer triggers an update in React 16.

class Mocktail extends React.Component {
    componentWillReceiveProps() {
        console.log('updated either by new props or setState');
    }
    updateMocktail = newMocktail => {
        this.setState(oldState => {
            if (oldState.mocktail === newMocktail) {
                return null;
            } else {
                return {
                    mocktail: newMocktail
                };
            }
        });
    }
}