Tooltip utils

This article will help you to install, import, and use tooltip utils. This util is useful for tooltip customizations in Power BI visuals.

Prerequisites

To use the package, you need:

Installation

To install the package, you should run the following command in the directory with your current visual:

npm install powerbi-visuals-utils-tooltiputils --save

This command installs the package and adds a package as a dependency to your package.json file.

Usage

The Usage Guide describes a public API of the package. You will find a description and some examples for each public interface of the package.

This package provides you with a way to create TooltipServiceWrapper and methods to help handle tooltip actions. It uses tooltip interfaces - ITooltipServiceWrapper, TooltipEventArgs, TooltipEnabledDataPoint.

It has specific methods (touch events handlers) related to mobile development: touchEndEventName, touchStartEventName, usePointerEvents.

TooltipServiceWrapper provides the simplest way to manipulate tooltips.

This module provides the following interface and function:

createTooltipServiceWrapper

This function creates an instance of ITooltipServiceWrapper.

function createTooltipServiceWrapper(tooltipService: ITooltipService, rootElement: Element, handleTouchDelay?: number,  getEventMethod?: () => MouseEvent): ITooltipServiceWrapper;

The ITooltipService is available in IVisualHost.

Example:

import { createTooltipServiceWrapper } from "powerbi-visuals-utils-tooltiputils";

export class YourVisual implements IVisual {
    // implementation of IVisual.

    constructor(options: VisualConstructorOptions) {
        createTooltipServiceWrapper(
            options.host.tooltipService,
            options.element);

        // returns: an instance of ITooltipServiceWrapper.
    }
}

See an example of the custom visual here.

ITooltipServiceWrapper

This interface describes public methods of the TooltipService.

interface ITooltipServiceWrapper {
    addTooltip<T>(selection: d3.Selection<any, any, any, any>, getTooltipInfoDelegate: (args: TooltipEventArgs<T>) => powerbi.extensibility.VisualTooltipDataItem[], getDataPointIdentity?: (args: TooltipEventArgs<T>) => powerbi.visuals.ISelectionId, reloadTooltipDataOnMouseMove?: boolean): void;
    hide(): void;
}

ITooltipServiceWrapper.addTooltip

This method adds tooltips to the current selection.

addTooltip<T>(selection: d3.Selection<any>, getTooltipInfoDelegate: (args: TooltipEventArgs<T>) => VisualTooltipDataItem[], getDataPointIdentity?: (args: TooltipEventArgs<T>) => ISelectionId, reloadTooltipDataOnMouseMove?: boolean): void;

Example:

import { createTooltipServiceWrapper, TooltipEventArgs, ITooltipServiceWrapper, TooltipEnabledDataPoint } from "powerbi-visuals-utils-tooltiputils";

let bodyElement = d3.select("body");

let element = bodyElement
    .append("div")
    .style({
        "background-color": "green",
        "width": "150px",
        "height": "150px"
    })
    .classed("visual", true)
    .data([{
        tooltipInfo: [{
            displayName: "Power BI",
            value: 2016
        }]
    }]);

let tooltipServiceWrapper: ITooltipServiceWrapper = createTooltipServiceWrapper(tooltipService, bodyElement.get(0)); // tooltipService is from the IVisualHost.

tooltipServiceWrapper.addTooltip<TooltipEnabledDataPoint>(element, (eventArgs: TooltipEventArgs<TooltipEnabledDataPoint>) => {
    return eventArgs.data.tooltipInfo;
});

// You will see a tooltip if you mouseover the element.

See an example of the custom visual here.

See an example of tooltip customization in a Gantt custom visual here.

ITooltipServiceWrapper.hide

This method hides the tooltip.

hide(): void;

Example:

import {createTooltipServiceWrapper} from "powerbi-visuals-utils-tooltiputils";

let tooltipServiceWrapper = createTooltipServiceWrapper(options.host.tooltipService, options.element); // options are from the VisualConstructorOptions.

tooltipServiceWrapper.hide();

Interfaces

Interfaces are used during TooltipServiceWrapper creation and when it's used. They were mentioned in examples from previous articles here.

TooltipEventArgs

interface TooltipEventArgs<TData> {
    data: TData;
    coordinates: number[];
    elementCoordinates: number[];
    context: HTMLElement;
    isTouchEvent: boolean;
}

TooltipEnabledDataPoint

interface TooltipEnabledDataPoint {
    tooltipInfo?: powerbi.extensibility.VisualTooltipDataItem[];
}

TooltipServiceWrapperOptions

interface TooltipServiceWrapperOptions {
    tooltipService: ITooltipService;
    rootElement: Element;
    handleTouchDelay: number;

Touch events

Now tooltip utils can handle several touch events that are useful for mobile development.

touchStartEventName

function touchStartEventName(): string

This method returns a touch start event name.

touchEndEventName

function touchEndEventName(): string

This method returns a touch end event name.

usePointerEvents

function usePointerEvents(): boolean

This method returns the current touchStart event related to a pointer or not.