Custom tooltip contents @ ngx-charts | Angular2+ |

Question

I've been trying to set a custom label in a line chart's tooltip , e.g., modified number of minutes in HH:mm format (74 min --> 1:14), for quite some time now, but unfortunately without any success. Displaying the value as 1.283(...3) is not an alternative.

Number to HH:mm as tooltip label

Does anybody know how to preserve the x and y axis values (a date and a number respectively), and modify the tooltip display value?

For example: https://swimlane.github.io/ngx-charts/#/ngx-charts/line-chart

Instead of having a tooltip that displays Color, Country name and Number, --> Color, Country name and String (Number > 3000 ? 'high' : 'low';)

Current behavior Works as intended.

Expected behavior To display custom labels.

Reproduction of the problem Link in the description above

What is the motivation / use case for changing the behavior? Being able to customize tooltips' contents

Please tell us about your environment: OS: Win 10 x64, IDE: Eclipse EE

ngx-charts version: 3.0.2

Angular version: 6.0.2

Browser: [all]

Language: [TypeScript 2.3.3]

Answer 1

The above solution does not work for multi-dimensional charts ( > 3) like Stacked Horizontal/Vertical Bar.

Another simple way which works for all cases is to add the tooltipText as an attribute as part of the model like below:

export let multi = [
  {
    name: 'Germany',
    series: [
      {
        name: '2010',
        value: 7300000,
        tooltipText: 't1'
      },
      {
        name: '2011',
        value: 8940000,
        tooltipText: 't2'
      }
    ]
  }
];

Then use the following code in markup,

<ngx-charts-bar-horizontal-stacked
      [view]="view"
      [scheme]="colorScheme"
      [results]="multi"
      [gradient]="gradient"
      [xAxis]="showXAxis"
      [yAxis]="showYAxis"
      [legend]="showLegend"
      [legendPosition]="legendPosition"
      [showXAxisLabel]="showXAxisLabel"
      [showYAxisLabel]="showYAxisLabel"
      [xAxisLabel]="xAxisLabel"
      [yAxisLabel]="yAxisLabel"
      (select)="onSelect($event)">
  <ng-template #tooltipTemplate let-model="model">
    <div class="tooltip">
      {{model.tooltipText}}
    </div>
  </ng-template>
</ngx-charts-bar-horizontal-stacked>

Answer 2

You can define your own tooltip templates and render any HTML you like in them:

<ngx-charts-line-chart        
    [scheme]="colorScheme"
    [results]="multi" ...>
  <ng-template #tooltipTemplate let-model="model">
    This is the single point tooltip template
    <pre>{{model|json}}</pre>
  </ng-template>

  <ng-template #seriesTooltipTemplate let-model="model">
    This is vertical line tooltip template
    <pre>{{model|json}}</pre>        
  </ng-template>
</ngx-charts-line-chart>

Example: https://swimlane.github.io/ngx-charts/#/ngx-charts/tooltip-templates

Code is here: https://github.com/swimlane/ngx-charts/blob/8ebb3dbcbbea443fefdcafd1f5c9069df0e0c4ae/src/app/app.component.html#L992-L998

Answer 3

Thank you, once again. Didn't want to leave the issue unresolved. The problem was the code snippet was inside a svg element. Here's the final version:

<!--  This is single point tooltip template -->
<xhtml:ng-template #tooltipTemplate let-model="model">
  <xhtml:div class="area-tooltip-container">
    <xhtml:div *ngFor="let tooltipItem of model | json | durationHhmm" class="tooltip-item" style="text-align: center;">
      <a style=" font-size: 1.2em;">{{tooltipItem.series}}</a><a *ngIf="tooltipShowTime==='DAY' || tooltipShowTime==='WEEK'" style=" font-size: 1.2em;"><br />{{tooltipItem.name | date: 'HH:mm'}} Uhr</a><a *ngIf="tooltipShowTime!=='DAY' && tooltipShowTime!=='WEEK'" style=" font-size: 1.3em; font-weight: 600;"><br />&#183;</a><br /><a style=" font-size: 1.2em; font-weight: 600;">{{tooltipItem.name | date: 'dd.MM.yyyy'}} &#183; </a><a style=" font-size: 1.3em; font-weight: 600;">{{tooltipItem.value}}</a>
    </xhtml:div>
  </xhtml:div>
</xhtml:ng-template>

<!-- Datapoints Y-Axis -->
<svg:g *ngFor="let series of data">
  <svg:g ngx-charts-circle-series
         [xScale]="xScale"
         [yScale]="yScale"
         [colors]="colors"
         [data]="series"
         [scaleType]="scaleType"
         [visibleValue]="hoveredVertical"
         [activeEntries]="activeEntries"
         [tooltipDisabled]="tooltipDisabled"
         [tooltipTemplate]="tooltipTemplate"
         (select)="onClick($event, series)"
         (activate)="onActivate($event)"
         (deactivate)="onDeactivate($event)"
  /> 
</svg:g>