ECharts 实例代码触发 ECharts 中组件的行为

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>ECharts 实例 代码触发 ECharts 中组件的行为</title>
    
    <script src="https://cdn.staticfile.org/echarts/4.8.0/echarts.min.js"></script>
</head>
<body>
    
    <div id="main"  style="height: 100%;min-height:400px;"></div>
    <script type="text/javascript">
        // 基于准备好的dom，初始化ECharts实例
        var myChart = echarts.init(document.getElementById('main'));
        var app = {};
        option = null;
        // 指定图表的配置项和数据
        var option = {
            title : {
                text: '饼图程序调用高亮示例',
                x: 'center'
            },
            tooltip: {
                trigger: 'item',
                formatter: "{a} <br/>{b} : {c} ({d}%)"
            },
            legend: {
                orient: 'vertical',
                left: 'left',
                data: ['直接访问','邮件营销','联盟广告','视频广告','搜索引擎']
            },
            series : [
                {
                    name: '访问来源',
                    type: 'pie',
                    radius : '55%',
                    center: ['50%', '60%'],
                    data:[
                        {value:335, name:'直接访问'},
                        {value:310, name:'邮件营销'},
                        {value:234, name:'联盟广告'},
                        {value:135, name:'视频广告'},
                        {value:1548, name:'搜索引擎'}
                    ],
                    itemStyle: {
                        emphasis: {
                            shadowBlur: 10,
                            shadowOffsetX: 0,
                            shadowColor: 'rgba(0, 0, 0, 0.5)'
                        }
                    }
                }
            ]
        };

app.currentIndex = -1;

setInterval(function () {
            var dataLen = option.series[0].data.length;
            // 取消之前高亮的图形
            myChart.dispatchAction({
                type: 'downplay',
                seriesIndex: 0,
                dataIndex: app.currentIndex
            });
            app.currentIndex = (app.currentIndex + 1) % dataLen;
            // 高亮当前图形
            myChart.dispatchAction({
                type: 'highlight',
                seriesIndex: 0,
                dataIndex: app.currentIndex
            });
            // 显示 tooltip
            myChart.dispatchAction({
                type: 'showTip',
                seriesIndex: 0,
                dataIndex: app.currentIndex
            });
        }, 1000);
        if (option && typeof option === "object") {
            myChart.setOption(option, true);
        }
    </script>
</body>
</html>