React - Hide content after a timer

Expire.jsx

'use strict';
import React from 'react';
import update from 'immutability-helper';

export default class Expire extends React.Component {
	constructor(props) {
		super(props);

		this.state = {
			delay: props.delay || 1000,
			visible: true
		}

		this.setTimer = this.setTimer.bind(this);
	}

	componentWillReceiveProps(nextProps) {
		 if (nextProps.children !== this.props.children) {
	      this.setTimer();
	      this.setState(update(this.state, {
	      	visible: {$set: true }
	      }))

	    }
	}
	componentDidMount() { this.setTimer(); }

	componentWillUnmount() { clearTimeout(this._timer); }

	setTimer() {
		// clear any existing timer
	    this._timer != null ? clearTimeout(this._timer) : null;

	    // hide after `delay` milliseconds
	    this._timer = setTimeout(function(){
	      this.setState({visible: false});
	      this._timer = null;
	      if(this.props.callback) {

	      	this.props.callback();
	      }
	    }.bind(this), this.props.delay);
	}
	render() {
		return this.state.visible
           ? <div>{this.props.children}</div>
           : <span />;
	}
}