Bubble API

Gravity-clustered circles sized by value, each optionally split into a realized core and an untapped ring - see the Bubble demo.

Import

Web Component

import "@michi-vz/wc/bubble-chart";
// <michi-vz-bubble-chart> is now defined

Vanilla JS

import { mountBubbleChart } from "@michi-vz/core";

const chart = mountBubbleChart(el, props);

Props

Prop	Type	Default	Description
timeline	boolean | TimelinePeriodConfig	-	Opt-in "play through years": snapshots one period at a time over the distinct per-row `date` values, with a headless controller (`chart.timeline()`) plus an optional built-in play button + scrubber. Off by default; requires rows with `date`. Values tween between periods unless `interpolate: false`.
dataSet*	BubbleDataItem[]	-	Array of bubbles; each value sets the circle area (bubbles are gravity-packed into a cluster)
title	string	-	Optional chart title rendered above the plot
gravity	number	0.09	Strength of the pull toward the centre in [0,1] (default 0.09) - higher = tighter cluster ("suck together").
chargeStrength	number	0	Many-body charge: negative repels, positive attracts (default 0).
padding	number	2	Gap between packed circles in px (default 2).
fillRatio	number	0.62	Fraction of the plot area the bubbles should fill, in (0,1] (default 0.62).
layoutMode	"sync" | "async"	"sync"	How the force layout settles: "sync" (default; identical layout every render, blocks until settled) or "async" (the SAME deterministic settle, run in ~12ms slices so thousands of bubbles never freeze the page; the loading overlay shows while it runs).
settleTicks	number	400	Force-simulation ticks to settle (default 400); fewer = faster but looser.
splitLabels	[string, string]	["Realized", "Untapped"]	Names of the two split parts (default ["Realized","Untapped"]).
splitOpacity	number	0.35	Apparent colour strength of the untapped veil in [0,1] (default 0.35); rendered as solid colour under a white veil so it reads as a lighter tint of the same hue on any background.
showSplit	boolean	-	Render the realized/untapped split. Defaults to auto-on when any item has `partial`.
showLegend	boolean	false	Render a 2-swatch split legend (uses splitLabels).
showLabels	boolean	true	Draw the label inside each bubble when it is large enough (default true).
filter	{ limit: number; sortingDir: "asc" | "desc" }	-	Keep only the top-N bubbles by value.
valueFormatter	(n: number) => string	-	Formats a numeric value for labels and tooltips
tooltipFormatter	(bubble: BubbleContext) => string	-	Returns custom tooltip HTML for a hovered datum/mark (sanitized before it is inserted)
onHighlightItem	(labels: string[]) => void	-	Called when the hovered/highlighted label(s) change

Common props - shared by every chart (14)

Prop	Type	Default	Description
width	number	700	Chart width in pixels
height	number	500	Chart height in pixels
margin	Margin	{ top: 36, right: 8, bottom: 8, left: 8 }	Inner margins (top/right/bottom/left, in px); default 8 (36 top with a title)
colors	string[]	-	Categorical palette for rings without an explicit colour or colorsMapping entry
colorsMapping	Record<string, string>	-	Explicit label -> colour map; takes precedence over the palette and per-item colours
highlightItems	string[]	-	Labels to emphasise (active styling); others keep their base opacity
disabledItems	string[]	-	Labels to hide entirely (ring + track removed; remaining rings keep their radii order)
renderer	"svg" | "canvas" | "webgpu"	"svg"	Render as inline SVG (default) or to a canvas / WebGPU layer; getContext() is identical either way
locale	string	-	BCP-47 locale used for number formatting
skipColorMappingDispatch	boolean	false	External-CSS mode: unmapped labels resolve to transparent and onColorMappingGenerated is not emitted, so arc colours come from your CSS via the data-label-safe contract
enableTransitions	boolean	true	Animate opacity/arc changes with CSS transitions (SVG renderer; default true)
onColorMappingGenerated	(mapping: Record<string, string>) => void	-	Called with the resolved label -> colour map after the chart assigns colours
onChartDataProcessed	(context: ChartContext) => void	-	Called with the renderer-agnostic ChartContext whenever the data is (re)processed
onDataWarning	(warnings: DataWarning[]) => void	-	Called with any non-fatal data warnings (out-of-range values, duplicate labels, ...)

Events

The web component dispatches these bubbling CustomEvents (the engine exposes the same via the on* callbacks in the table above):

Event	Detail	Fires when
michi-vz:highlight	string[]	hover highlight changes
michi-vz:colormapping	Record<string, string>	a color mapping is generated
michi-vz:dataprocessed	ChartContext	data is (re)processed
michi-vz:datawarning	DataWarning[]	input warnings are detected

getContext()

mountBubbleChart(el, props).getContext() returns a renderer-agnostic BubbleChartContext: the flat bubbles (value / partial / remainder / percent), splitLabels, summary stats (bubble count, total, totals per part, largest bubble, largest remainder), a deterministic natural-language summary, and an a11y table. See LLM context.

Source

Props are typed as BubbleChartProps in @michi-vz/core.