ngx-d3-tooltip

Add tooltips to your d3 visualizations using Angular Components.

Why?

D3.js is a great visualization library, but building dynamic tooltips is a bit clunky. Angular is an app framework and has great html templating and data-binding, which are features that are ideal for more-than-trivial tooltips. This project aims to achieve the best of both worlds.

Installation

1. Install ngx-d3-tooltip with npm

npm install ngx-d3-tooltip

1. Add D3TooltipModule to your app module's imports

// ...
import { D3TooltipModule } from 'ngx-d3-tooltip';

// ...in @NgModule:
  imports: [
    D3TooltipModule
  ],
// ...

Usage

The main idea is that the D3TooltipService.createFromComponent method returns a function which is then passed to your d3.Selection.call :

let tooltip = d3TooltipService.createFromComponent(MyComponent, inputs, outputs, options);
svg.selectAll('rect.example')
  .data(myData)
  .enter()
  .call(tooltip);

Here is a more in-depth example:

1. Create the component you want to use as a tooltip

// my-tooltip.component.ts:

@Component({
  selector: 'my-tooltip',
  template: `
    <h3>{{ myData.name }}</h3>
    <p>{{ myData.someText }}</p>
  `
})
export class MyTooltipComponent {
  
  // Most commonly, you will be passing the d3 element datum
  // to this component, exemplified here (assuming the data
  // bound to the element with this the tooltip is of type 
  // IMyDatum)
  @Input()
  myDatum: IMyDatum;

  // Outputs work as well!
  @Output()
  update: EventEmitter<any>;
}

1. Add the component to your module's entryComponents array

// app.module.ts:

// ...
import { MyTooltipComponent } from './components/d3-tooltip.component';
import { MyOtherTooltipComponent } from './components/d3-other-tooltip.component';

// ...in @NgModule:
  entryComponents: [
    MyTooltipComponent,
    MyOtherTooltipComponent
  ],
// ...

1. In your d3 code, create the tooltip function and invoke it with d3.Selection.call

// my-d3-chart.component.ts:
// Import the component tooltip
import { MyTooltipComponent } from './components/d3-tooltip.component';
@Component({ /* ... */ })
export class MyD3ChartComponent {
  tooltip: (selection) => void;  
  constructor(private tipService: D3TooltipService) { // <-- inject the tooltip service
    // create the tooltip function, to be passed to .call()
    this.tooltip = tipService.createFromComponent(
      // The component to insert into the tooltip
      MyTooltipComponent,
      // A function which takes the d3 datum of the current element and returns an object
      // where the keys are @Input property names.
      (d: IMyDatum) => {
        return { myDatum: d }
      },
      // A function which returns an object where keys are @Output property names of the
      // tooltip component and values are handlers passed to the output's subscribe()
      () => {
        return {
          update: (d: IMyDatum) => {
            // do something here...
          }
        }
      },
      { /* other options available */}
    );
  }
  render() {
    // ...set up d3 elements...
    // d3 render code:
    let rect = svg.selectAll('rect.example')
      .data(myData);
    rect.enter()
      .append('rect')
      .classed('example', true)
      .call(this.tooltip); // <-- Use on a selection like this
  }
}

Running the Demo

npm start

Documentation

Documentation

TODOs:

• tests
• position: auto support
• raw template support

License

MIT