componentWillReceiveProps

Updating: componentWillReceiveProps

void componentWillReceiveProps(
  object nextProps
)

Invoked when a component is receiving new props. This method is not called for the initial render.

Use this as an opportunity to react to a prop transition before render() is called by updating the state using this.setState(). The old props can be accessed via this.props. Calling this.setState() within this function will not trigger an additional render.

componentWillReceiveProps: function(nextProps) {
  this.setState({
    likesIncreasing: nextProps.likeCount > this.props.likeCount
  });
}

One common mistake is for code executed during this lifecycle method to assume that props have changed. To understand why this is invalid, read A implies B does not imply B implies A

There is no analogous method componentWillReceiveState. An incoming prop transition may cause a state change, but the opposite is not true. If you need to perform operations in response to a state change, use componentWillUpdate.