Customize the event handler of Legend

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/babel-core/5.8.24/browser.js"></script>
<script src="https://npmcdn.com/[email protected]/dist/react-with-addons.min.js"></script>
<script src="https://npmcdn.com/[email protected]/dist/react-dom.min.js"></script>
<script src="https://npmcdn.com/prop-types/prop-types.min.js"></script>
<script src="https://npmcdn.com/recharts/umd/Recharts.min.js"></script>
<div id="container">
    <!-- This element's contents will be replaced with your component. -->
</div>

CSS

body {
  margin: 0;
}
#container {
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
  padding: 10px;
  width: 800px;
  height: 800px;
  background-color: #fff;
}

Babel + JSX

const {LineChart, Line, XAxis, YAxis, CartesianGrid, Tooltip, Legend} = Recharts;
const data = [
      {name: new Date('2018-01-01'), uv: 4000, pv: 2400, amt: 2400},
      {name: new Date('2018-02-01'), uv: 3000, pv: 1398, amt: 2210},
      {name: new Date('2018-03-01'), uv: 2000, pv: 9800, amt: 2290},
      {name: new Date('2018-04-01'), uv: 2780, pv: 3908, amt: 2000},
      {name: new Date('2018-05-01'), uv: 1890, pv: 4800, amt: 2181},
      {name: new Date('2018-06-01'), uv: 2390, pv: 3800, amt: 2500},
      {name: new Date('2018-07-01'), uv: 3490, pv: 4300, amt: 2100},
];
const SimpleLineChart = React.createClass({
	getInitialState() {
  	return {
    	opacity: {
      	uv: 1,
        pv: 1,
      },
      vis: true
    };
  },
  
  handleMouseEnter(o) {
    const { dataKey } = o;
    const { opacity } = this.state;
    
  	this.setState({
    	opacity: { ...opacity, [dataKey]: 0.5 },
    });
  },
  
  handleMouseLeave(o) {
  	const { dataKey } = o;
    const { opacity } = this.state;
    
  	this.setState({
    	opacity: { ...opacity, [dataKey]: 1 },
    });
  },
	
	render () {
  	const { opacity } = this.state;
    
  	return (
    	<div>
        <LineChart width={600} height={300} data={data}
              margin={{top: 5, right: 30, left: 20, bottom: 5}}>
         <CartesianGrid strokeDasharray="3 3"/>
         <XAxis dataKey={(obj)=>obj.name.toString()}/>
         <YAxis/>
         <Tooltip/>
         <Legend onMouseEnter={this.handleMouseEnter} onMouseLeave={this.handleMouseLeave} onClick={(obj)=>{
         console.log(obj)
         return this.setState({vis: !this.state.vis})}}/>
         <Line type="monotone" dataKey="pv" strokeOpacity={10} stroke="#8884d8" activeDot={{r: 19}}/>
         <Line type="monotone" dataKey={this.state.vis ? 'uv' : 'uv_'} strokeOpacity={opacity.uv} 
         strokeWidth={4} stroke="#82ca9d" />
        </LineChart> 
        <p className="notes">Tips: Hover the legend !</p>
      </div>
    );
  }
})

ReactDOM.render(
 ...