@d3-maps/core / map

map

Table of contents

• Functions
  • getTopoObject()
  • isTopology()
  • makeFeatures()
  • makeMapContext()
  • makeMesh()
  • makeProjection()
• Interfaces
  • MapConfig
  • MapContext
  • ProjectionConfig
• Type Aliases
  • DataTransformer()
  • MapData
  • MapMesh

Functions

getTopoObject()

function getTopoObject(geoData: Topology): GeometryObject;

Parameters

Parameter	Type
geoData	Topology

Returns

GeometryObject

---

isTopology()

function isTopology(data: MapData): data is Topology<Objects<GeoJsonProperties>>;

Type guard for TopoJSON topology inputs.

Parameters

Parameter	Type
data	MapData

Returns

data is Topology<Objects<GeoJsonProperties>>

---

makeFeatures()

function makeFeatures(geoData: MapData, dataTransformer?: DataTransformer): MapFeature[];

Normalizes input map data to GeoJSON features.

• TopoJSON is converted via topojson-client.
• If provided, dataTransformer is applied to the feature array.

Parameters

Parameter	Type
geoData	MapData
dataTransformer?	DataTransformer

Returns

MapFeature[]

---

makeMapContext()

function makeMapContext(__namedParameters: MapConfig): MapContext;

Creates a full MapContext from a MapConfig.

Parameters

Parameter	Type
__namedParameters	MapConfig

Returns

MapContext

---

makeMesh()

function makeMesh(geoData: MapData): MultiLineString | undefined;

Returns a TopoJSON mesh when topology data is provided.

Parameters

Parameter	Type
geoData	MapData

Returns

MultiLineString | undefined

---

makeProjection()

function makeProjection(__namedParameters: {
  config?: ProjectionConfig;
  height: number;
  projection: () => GeoProjection;
  width: number;
}): GeoProjection;

Creates a configured projection and fits it to the provided GeoJSON (if present).

Parameters

Parameter	Type
__namedParameters	{ config?: ProjectionConfig; height: number; projection: () => GeoProjection; width: number; }
__namedParameters.config?	ProjectionConfig
__namedParameters.height	number
__namedParameters.projection	() => GeoProjection
__namedParameters.width	number

Returns

GeoProjection

Interfaces

MapConfig

Input configuration for creating a map context.

In adapters, this is usually passed as component props.

Properties

Property	Type	Description
aspectRatio?	number	-
data	MapData	TopoJSON or GeoJSON input. TopoJSON is automatically converted to GeoJSON features.
dataTransformer?	DataTransformer	Optional feature transformer (filter/augment/normalize features).
height?	number	-
projection?	() => GeoProjection	Projection factory from d3-geo (or a compatible implementation). Example: geoNaturalEarth1.
projectionConfig?	ProjectionConfig	Projection method arguments passed to the created projection
width?	number	-

---

MapContext

Fully computed, framework-agnostic map context.

Adapters provide this context to child layers (features, markers, custom SVG).

Properties

Property	Type
features	MapFeature[]
height	number
path	GeoPath
projection?	GeoProjection
renderMesh	() => void
width	number

---

ProjectionConfig

Extra projection method calls to apply before rendering.

Use projection method names as keys and method arguments as values. Example: { center: [[0, 20]], rotate: [[0, 0, 0]], scale: 160 }

See

https://d3js.org/d3-geo/projection

Extends

• Omit<MethodsToModifiers<GeoProjection>, "invert" | "stream">

Properties

Property	Type	Inherited from
angle?	number	[number]
center?	[[number, number]]	ProjectionConfig.center
clipAngle?	number	[number]
clipExtent?	[[[number, number], [number, number]]]	[null]
fitExtent?	[[[number, number], [number, number]],	GeoGeometryObjects
fitHeight?	[number,	GeoGeometryObjects
fitSize?	[[number, number],	GeoGeometryObjects
fitWidth?	[number,	GeoGeometryObjects
postclip?		(stream: GeoStream) => GeoStream
precision?	number	[number]
preclip?		(stream: GeoStream) => GeoStream
reflectX?	boolean	[false]
reflectY?	boolean	[false]
rotate?	[[number, number]]	[[number, number, number]]
scale?	number	[number]
translate?	[[number, number]]	ProjectionConfig.translate

Type Aliases

DataTransformer()

type DataTransformer = (features: MapFeature[]) => MapFeature[];

Parameters

Parameter	Type
features	MapFeature[]

Returns

MapFeature[]

---

MapData

type MapData = ExtendedFeatureCollection | Topology;

---

MapMesh

type MapMesh = ReturnType<typeof mesh>;