Update echart on data change - html

Question

i'm looking for a solution to update an echart when new data comes in. Currently i have a chart and a drop down with some data.When i open the page, data is displaying at the chart perfectly fine. But when i use the drop down and change option to next data, nothing is happening. The previous data is still on the chart. Any ideas how to update the chart (object) when data changes ?
My code:
chart1: EChartOption = {
tooltip: {
trigger: 'axis',
axisPointer: {
type: 'shadow'
}
},
legend: {
data: ['Tests Open','Tests Approved', 'Tests Failed']
},
toolbox: {
show: true,
feature: {
mark: { show: true },
magicType: { title: '1', show: true, type: ['line', 'bar',] },
restore: { title: 'Restore', show: true },
saveAsImage: { title: 'Save Chart',show: true }
}
},
xAxis: [
{
type: 'category',
axisTick: { show: false },
data: []
}
],
yAxis: [
{
type: 'value'
}
],
series: [
{
name: 'Tests Open',
type: 'bar',
data: [],
itemStyle: {
color: '#FDD051'
}
},
{
name: 'Tests Approved',
type: 'bar',
data: [],
itemStyle: {
color: '#2EAD6D'
}
},
{
name: 'Tests Failed',
type: 'bar',
data: [],
itemStyle: {
color:'#F0533F'
}
},
]
};
refreshChart(statistics: TestResultSiteStatistics) : void {
let months = [];
let open = [];
let approved = [];
let failed = [];
for (let month in statistics.monthly){
months.push(month);
approved.push(statistics.monthly[month].approved);
open.push(statistics.monthly[month].open);
failed.push(statistics.monthly[month].failed);
}
this.chart1.xAxis[0].data = months;
this.chart1.series[0].data = open;
this.chart1.series[1].data = failed;
this.chart1.series[2].data = approved;
}
<div #chart style="height:590px; width:1190px;" echarts [options]="chart1" ></div>

Answer 1

You cannot add data directly to instance because Echarts incapsulated diffucult logic to process data. You need to use method myChart.setOption({series: [new_data]}). It explained in API docs: https://echarts.apache.org/en/api.html#echartsInstance.setOption and https://echarts.apache.org/en/tutorial.html#Loading%20and%20Updating%20of%20Asynchronous%20Data