Tooltip does not show anymore on graphs when data in NULL.
When I was using ecahrts 3.4.0 and I had a graph that was filled with null or undefined. it would show me a tooltip and I used the formatter to make it say N/A when the value is null or undefined.
Today I updated to the latest version (3.7.1) and realized that tooltips dont show anymore so I downgraded to 3.4.0, it was working again. I went up 1 version (3.5.0) and it was broke so its from that version that this happened.
I looked at the documentation again now to see if something is changed but I couldn't find anything.
option = {
title: {
text: '',
subtext: ''
},
tooltip: {
show: true,
trigger: 'axis',
axisPointer: {
show: true,
type: 'cross',
label: {
show: true
}
},
formatter: function (params) {
console.log('value is ' + params); //THIS LINE DOES NOT RUN..
let value = '';
if(params[0].data === undefined || params[0].data === null) {
value = 'N/A';
} else {
value = (params[0].data).toFixed(2);
}
let text = "<span style=\"color:" + params[0].color + "\">\u25CF</span> " + params[0].seriesName + ": " + value;
return params[0].name + "<br />" + text;
}
},
axisPointer: {
show: true,
type: 'line'
},
legend: {
show: false
},
toolbox: {
show: true,
feature: {
magicType: {
show: true,
title: {
line: 'Line',
bar: 'Bar'
},
type: ['line', 'bar']
},
restore: {
show: true,
title: "Restore"
},
saveAsImage: {
show: true,
title: "Save Image"
}
}
},
calculable: true,
xAxis: [{
type: 'category',
boundaryGap: false,
data: []
}],
yAxis: [{
type: 'value',
min: 0,
max: 20
}],
series: [{
name: 'TPS',
type: 'line',
smooth: true,
itemStyle: {
normal: {
areaStyle: {
type: 'default'
}
}
},
data: []
}]
}
What the graph tooltip should look like:

What it looks like now:

It behaves like this as I test your code with v3.7.1.

This makes sense since you set the axisPoint.
So is this what you want?
No I want to tooltip to show as well. If you look at my options, I have a formatter that if the params[0].data is NULL or undefined the tooltip should show "N/A" like in the photo that I provided.
Did you forget to copy the data of xAxis here?
The data is loaded after the page loads. It is not static.
This is how the data for x and y axis are loaded.

I did some more testing on this issue and I am almost certain that it is a bug.
When the graph is completely full of null or undefined the tooltip does not show. But when the graph has at least 1 value the tooltips show for the null area. Look at my screenshot below.

The parts that say N/A is my formatter code above.
I have the same problem with the graph visualisation. Copied the structure of the graph (options) from another project, the first shows the tooltip while the second does not. I could not find a solution for displaying it.
I had the same issue with the tooltip not showing up using echarts within a Vue project. After a while I realized that I have to import different components I make use of in the chart. Amongst these is the tooltip component. The following resolved the issue for me:
import ECharts from "vue-echarts";
import "echarts/lib/chart/scatter";
import "echarts/lib/component/dataZoom";
import "echarts/lib/component/tooltip"; // you need to import the tooltip component
Most helpful comment
I had the same issue with the tooltip not showing up using echarts within a Vue project. After a while I realized that I have to import different components I make use of in the chart. Amongst these is the tooltip component. The following resolved the issue for me: