@d3-maps/core / map

map

Table of contents

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

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): MapFeatureData[];

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

MapFeatureData[]

---

makeMapContext()

function makeMapContext(__namedParameters: MapProps): MapContext;

Creates a full MapContext from a MapProps.

Parameters

Parameter	Type
__namedParameters	MapProps

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

MapContext

Fully computed, framework-agnostic map context.

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

Properties

Property	Type	Description
features	MapFeatureData[]	Normalized feature list after optional transformation.
height	number	Resolved SVG height used by the map.
path	GeoPath	Shared path generator bound to the map projection.
projection	GeoProjection	Configured projection instance shared by map layers.
renderMesh	() => string	null
width	number	Resolved SVG width used by the map.

---

MapProps

Shared props contract for the Map component.

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	-

---

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: MapFeatureData[]) => MapFeatureData[];

Parameters

Parameter	Type
features	MapFeatureData[]

Returns

MapFeatureData[]

---

MapData

type MapData = ExtendedFeatureCollection | Topology;

---

MapMeshData

type MapMeshData = ReturnType<typeof mesh>;