ol-mapbox-style

Create OpenLayers maps from Mapbox Style Specification objects.

Getting started

Get an impression of what this library does by exploring the live examples.

Installation

To use the library in an application with an npm based dev environment, install it with

npm install ol-mapbox-style

When installed this way, just import the ol-mapbox-style module, like in the usage example below. To use a standalone build of ol-mapbox-style, just include 'dist/olms.js' on your HTML page, and access the exported functions from the global olms object (e.g. olms.apply(), olms.applyBackground()). Note that the standalone build depends on the full build of OpenLayers.

ol-mapbox-style v9 requires OpenLayers version >= 7 < 8.

ol-mapbox-style v8 requires OpenLayers version >= 6.13.0 < 7.

Usage

See the API section for the full documentation.

The code below creates an OpenLayers map from Mapbox's Bright v9 style, using a https:// url:

import { apply } from 'ol-mapbox-style';

apply('map', 'https://api.mapbox.com/styles/v1/mapbox/bright-v9?access_token=YOUR_MAPBOX_TOKEN');

To assign style and source to a layer only, use applyStyle(). mapbox:// urls are also supported:

import {applyStyle} from 'ol-mapbox-style';
import VectorTileLayer from 'ol/layer/VectorTile.js'

const layer = new VectorTileLayer({declutter: true});
applyStyle(layer, 'mapbox://styles/mapbox/bright-v9', {accessToken: 'YOUR_MAPBOX_TOKEN'});

To apply the properties of the Mapbox Style's background layer to the map or a VectorTile layer, use the applyBackground() function.

There is also a low-level API available. To create a style function for individual OpenLayers vector or vector tile layers, use the stylefunction module:

import {stylefunction} from 'ol-mapbox-style';
import VectorLayer from 'ol/layer/Vector.js';
import VectorSource from 'ol/source/Vector.js';
import GeoJSON from 'ol/format/GeoJSON.js';

const layer = new VectorLayer({
  source: new VectorSource({
    format: new GeoJSON(),
    url: 'data/states.geojson'
  })
});

fetch('data/states.json').then(function(response) {
  response.json().then(function(glStyle) {
    stylefunction(layer, glStyle, 'states');
  });
});

Note that this low-level API does not create a source for the layer, and extra work is required to set up sprite handling for styles that use icons.

Compatibility notes

Font handling

ol-mapbox-style cannot use PBF/SDF glyphs for text-font layout property, as defined in the Mapbox Style specification. Instead, it relies on web fonts. A ol:webfonts metadata property can be set on the root of the Style object to specify a location for webfonts, e.g.

{
  "version": 8,
  "metadata": {
    "ol:webfonts": "https://my.server/fonts/{font-family}/{fontweight}{-fontstyle}.css"
  }
  // ...
}

The following placeholders can be used in the ol:webfonts url:

• {font-family}: CSS font family converted to lowercase, blanks replaced with -, e.g. noto-sans
• {Font+Family}: CSS font family in original case, blanks replaced with +, e.g. Noto+Sans
• {fontweight}: CSS font weight (numeric), e.g. 400, 700
• {fontstyle}: CSS font style, e.g. normal, italic
• {-fontstyle}: CSS font style other than normal, e.g. -italic or empty string for normal

If no metadata['ol:webfonts'] property is available on the Style object, Fontsource Fonts will be used. It is also possible for the application to load other fonts. If a font is already available in the browser, ol-mapbox-style will not load it.

Because of this difference, the font stack is treated a little different than defined in the spec: style and weight are taken from the primary font (i.e. the first one in the font stack). Subsequent fonts in the font stack are only used if the primary font is not available/loaded, and they will be used with the style and weight of the primary font.

Building the library

npm run build

The resulting distribution files will be in the dist/ folder. To see the library in action, navigate to dist/index.html.

To run test locally, run

npm test

For debugging tests in the browser, run

npm run karma

and open a browser on the host and port indicated in the console output (usually http://localhost:9876/) and click the 'DEBUG' button to go to the debug environment.

API

ol-mapbox-style

Table of contents

References

• default

Modules

• <internal\>

Classes

• MapboxVectorLayer

Functions

• addMapboxLayer
• apply
• applyBackground
• applyStyle
• getFeatureState
• getLayer
• getLayers
• getMapboxLayer
• getSource
• getStyleForLayer
• recordStyleLayer
• removeMapboxLayer
• renderTransparent
• setFeatureState
• stylefunction
• updateMapboxLayer

References

default

Renames and re-exports apply

Functions

addMapboxLayer

▸ addMapboxLayer(mapOrGroup, mapboxLayer, beforeLayerId?): Promise<void>

Add a new Mapbox Layer object to the style. The map will be re-rendered.

Parameters

Returns

Promise<void>

Resolves when the added layer is available.

apply

▸ apply(mapOrGroupOrElement, style, options?): Promise<Map | LayerGroup>

Loads and applies a Mapbox Style object into an OpenLayers Map or LayerGroup. This includes the map background, the layers, and for Map instances that did not have a View defined yet also the center and the zoom.

Example:

import apply from 'ol-mapbox-style';

apply('map', 'mapbox://styles/mapbox/bright-v9', {accessToken: 'YOUR_MAPBOX_TOKEN'});

The center and zoom will only be set if present in the Mapbox Style document, and if not already set on the OpenLayers map.

Layers will be added to the OpenLayers map, without affecting any layers that might already be set on the map.

Layers added by apply() will have two additional properties:

• mapbox-source: The id of the Mapbox Style document's source that the OpenLayers layer was created from. Usually apply() creates one OpenLayers layer per Mapbox Style source, unless the layer stack has layers from different sources in between.
• mapbox-layers: The ids of the Mapbox Style document's layers that are included in the OpenLayers layer.

This function sets an additional mapbox-style property on the OpenLayers Map or LayerGroup instance, which holds the Mapbox Style object.

Parameters

Returns

Promise<Map | LayerGroup>

A promise that resolves after all layers have been added to the OpenLayers Map instance or LayerGroup, their sources set, and their styles applied. The resolve callback will be called with the OpenLayers Map instance or LayerGroup as argument.

applyBackground

▸ applyBackground(mapOrLayer, glStyle, options?): Promise<any>

Applies properties of the Mapbox Style's first background layer to the provided map or layer (group).

Example:

import {applyBackground} from 'ol-mapbox-style';
import {Map} from 'ol';

const map = new Map({target: 'map'});
applyBackground(map, 'https://api.maptiler.com/maps/basic/style.json?key=YOUR_OPENMAPTILES_TOKEN');

Parameters

Returns

Promise<any>

Promise that resolves when the background is applied.

applyStyle

▸ applyStyle(layer, glStyle, sourceOrLayersOrOptions?, optionsOrPath?, resolutions?): Promise<any>

Applies a style function to an ol/layer/VectorTile or ol/layer/Vector with an ol/source/VectorTile or an ol/source/Vector. If the layer does not have a source yet, it will be created and populated from the information in the glStyle (unless updateSource is set to false).

Example:

import {applyStyle} from 'ol-mapbox-style';
import {VectorTile} from 'ol/layer.js';

const layer = new VectorTile({declutter: true});
applyStyle(layer, 'https://api.maptiler.com/maps/basic/style.json?key=YOUR_OPENMAPTILES_TOKEN');

The style function will render all layers from the glStyle object that use the source of the first layer, the specified source, or a subset of layers from the same source. The source needs to be a "type": "vector" or "type": "geojson" source.

Two additional properties will be set on the provided layer:

• mapbox-source: The id of the Mapbox Style document's source that the OpenLayers layer was created from. Usually apply() creates one OpenLayers layer per Mapbox Style source, unless the layer stack has layers from different sources in between.
• mapbox-layers: The ids of the Mapbox Style document's layers that are included in the OpenLayers layer.

Parameters

Returns

Promise<any>

Promise which will be resolved when the style can be used for rendering.

getFeatureState

▸ getFeatureState(mapOrLayer, feature): any

Sets or removes a feature state. The feature state is taken into account for styling, just like the feature's properties, and can be used e.g. to conditionally render selected features differently.

Parameters

Returns

any

Feature state or null when no feature state is set for the given feature identifier.

getLayer

▸ getLayer(map, layerId): Layer<Source, LayerRenderer<any>>

Get the OpenLayers layer instance that contains the provided Mapbox Style layer. Note that multiple Mapbox Style layers are combined in a single OpenLayers layer instance when they use the same Mapbox Style source.

Parameters

Returns

Layer<Source, LayerRenderer<any>>

OpenLayers layer instance.

getLayers

▸ getLayers(map, sourceId): Layer<Source, LayerRenderer<any>>[]

Get the OpenLayers layer instances for the provided Mapbox Style source.

Parameters

Returns

Layer<Source, LayerRenderer<any>>[]

OpenLayers layer instances.

getMapboxLayer

▸ getMapboxLayer(mapOrGroup, layerId): any

Get the Mapbox Layer object for the provided layerId.

Parameters

Returns

any

Mapbox Layer object.

getSource

▸ getSource(map, sourceId): Source

Get the OpenLayers source instance for the provided Mapbox Style source.

Parameters

Returns

Source

OpenLayers source instance.

getStyleForLayer

▸ getStyleForLayer(feature, resolution, olLayer, layerId): Style[]

Get the the style for a specific Mapbox layer only. This can be useful for creating a legend.

Parameters

Returns

Style[]

Styles for the provided Mapbox layer.

recordStyleLayer

▸ recordStyleLayer(record?): void

Turns recording of the Mapbox Style's layer on and off. When turned on, the layer that a rendered feature belongs to will be set as the feature's mapbox-layer property.

Parameters

Returns

void

removeMapboxLayer

▸ removeMapboxLayer(mapOrGroup, mapboxLayerIdOrLayer): void

Remove a Mapbox Layer object from the style. The map will be re-rendered.

Parameters

Returns

void

renderTransparent

▸ renderTransparent(enabled): void

Configure whether features with a transparent style should be rendered. When set to true, it will be possible to hit detect content that is not visible, like transparent fills of polygons, using ol/layer/Layer#getFeatures() or ol/Map#getFeaturesAtPixel()

Parameters

Returns

void

setFeatureState

▸ setFeatureState(mapOrLayer, feature, state): void

Sets or removes a feature state. The feature state is taken into account for styling, just like the feature's properties, and can be used e.g. to conditionally render selected features differently.

The feature state will be stored on the OpenLayers layer matching the feature identifier, in the mapbox-featurestate property.

Parameters

Returns

void

stylefunction

▸ stylefunction(olLayer, glStyle, sourceOrLayers, resolutions?, spriteData?, spriteImageUrl?, getFonts?, getImage?, ...args): StyleFunction

Creates a style function from the glStyle object for all layers that use the specified source, which needs to be a "type": "vector" or "type": "geojson" source and applies it to the specified OpenLayers layer.

Two additional properties will be set on the provided layer:

• mapbox-source: The id of the Mapbox Style document's source that the OpenLayers layer was created from. Usually apply() creates one OpenLayers layer per Mapbox Style source, unless the layer stack has layers from different sources in between.
• mapbox-layers: The ids of the Mapbox Style document's layers that are included in the OpenLayers layer.

This function also works in a web worker. In worker mode, the main thread needs to listen to messages from the worker and respond with another message to make sure that sprite image loading works:

 worker.addEventListener('message', event => {
  if (event.data.action === 'loadImage') {
    const image = new Image();
    image.crossOrigin = 'anonymous';
    image.addEventListener('load', function() {
      createImageBitmap(image, 0, 0, image.width, image.height).then(imageBitmap => {
        worker.postMessage({
          action: 'imageLoaded',
          image: imageBitmap,
          src: event.data.src
        }, [imageBitmap]);
      });
    });
    image.src = event.data.src;
  }
});

Parameters

Returns

StyleFunction

Style function for use in ol.layer.Vector or ol.layer.VectorTile.

updateMapboxLayer

▸ updateMapboxLayer(mapOrGroup, mapboxLayer): void

Update a Mapbox Layer object in the style. The map will be re-rendered with the new style.

Parameters

Returns

void

Class: MapboxVectorLayer

Classdesc

import {MapboxVectorLayer} from 'ol-mapbox-style';

A vector tile layer based on a Mapbox style that uses a single vector source. Configure the layer with the styleUrl and accessToken shown in Mapbox Studio's share panel. If the style uses more than one source, use the source property to choose a single vector source. If you want to render a subset of the layers in the style, use the layers property (all layers must share the same vector source). See the constructor options for more detail.

const map = new Map({
  view: new View({
    center: [0, 0],
    zoom: 1,
  }),
  layers: [
    new MapboxVectorLayer({
      styleUrl: 'mapbox://styles/mapbox/bright-v9',
      accessToken: 'your-mapbox-access-token-here',
    }),
  ],
  target: 'map',
});

On configuration or loading error, the layer will trigger an 'error' event. Listeners will receive an object with an error property that can be used to diagnose the problem.

Note for users of the full build: The MapboxVectorLayer requires the ol-mapbox-style library to be loaded as well.

Param

Options.

Fires

module:ol/events/Event~BaseEvent#event:error

Api

Hierarchy

• VectorTileLayer

  ↳ MapboxVectorLayer

Table of contents

Constructors

• constructor

Properties

• accessToken

Constructors

constructor

• new MapboxVectorLayer(options)

Parameters

Overrides

VectorTileLayer.constructor

Properties

accessToken

• accessToken: string

Interface: ApplyStyleOptions<>

.ApplyStyleOptions

Table of contents

Properties

• layers
• source
• updateSource

Properties

layers

• layers: string[]

Layers. If no source is provided, the layers with the provided ids will be used from the style's layers array. All layers need to use the same source.

source

• source: string

Source. Default is '', which causes the first source in the style to be used.

updateSource

• updateSource: boolean

Update or create vector (tile) layer source with parameters specified for the source in the mapbox style definition.

Interface: FeatureIdentifier<>

.FeatureIdentifier

Table of contents

Properties

• id
• source

Properties

id

• id: string | number

The feature id.

source

• source: string

The source id.

Interface: Options<>

.Options

Table of contents

Properties

• accessToken
• background
• className
• declutter
• extent
• layers
• map
• maxResolution
• maxZoom
• minResolution
• minZoom
• opacity
• preload
• properties
• renderBuffer
• renderMode
• renderOrder
• source
• styleUrl
• updateWhileAnimating
• updateWhileInteracting
• useInterimTilesOnError
• visible
• zIndex

Properties

accessToken

• accessToken: string

The access token for your Mapbox style. This has to be provided for mapbox:// style urls. For https:// and other urls, any access key must be the last query parameter of the style url.

background

• background: false | BackgroundColor

Background color for the layer. If not specified, the background from the Mapbox style object will be used. Set to false to prevent the Mapbox style's background from being used.

className

• className: string

A CSS class name to set to the layer element.

declutter

• declutter: boolean

Declutter images and text. Decluttering is applied to all image and text styles of all Vector and VectorTile layers that have set this to true. The priority is defined by the z-index of the layer, the zIndex of the style and the render order of features. Higher z-index means higher priority. Within the same z-index, a feature rendered before another has higher priority.

As an optimization decluttered features from layers with the same className are rendered above the fill and stroke styles of all of those layers regardless of z-index. To opt out of this behavior and place declutterd features with their own layer configure the layer with a className other than ol-layer.

extent

• extent: Extent

The bounding extent for layer rendering. The layer will not be rendered outside of this extent.

layers

• layers: string[]

Limit rendering to the list of included layers. All layers must share the same vector source. If your style uses more than one source, you need to use either the source property or the layers property to limit rendering to a single vector source.

map

• map: Map

Sets the layer as overlay on a map. The map will not manage this layer in its layers collection, and the layer will be rendered on top. This is useful for temporary layers. The standard way to add a layer to a map and have it managed by the map is to use map.addLayer().

maxResolution

• maxResolution: number

The maximum resolution (exclusive) below which this layer will be visible. If neither maxResolution nor minZoom are defined, the layer's maxResolution will match the style source's minzoom.

maxZoom

• maxZoom: number

The maximum view zoom level (inclusive) at which this layer will be visible.

minResolution

• minResolution: number

The minimum resolution (inclusive) at which this layer will be visible.

minZoom

• minZoom: number

The minimum view zoom level (exclusive) above which this layer will be visible. If neither maxResolution nor minZoom are defined, the layer's minZoom will match the style source's minzoom.

opacity

• opacity: number

Opacity (0, 1).

preload

• preload: number

Preload. Load low-resolution tiles up to preload levels. 0 means no preloading.

properties

• properties: Object

Arbitrary observable properties. Can be accessed with #get() and #set().

renderBuffer

• renderBuffer: number

The buffer in pixels around the tile extent used by the renderer when getting features from the vector tile for the rendering or hit-detection. Recommended value: Vector tiles are usually generated with a buffer, so this value should match the largest possible buffer of the used tiles. It should be at least the size of the largest point symbol or line width.

renderMode

• renderMode: VectorTileRenderType

Render mode for vector tiles:

• 'hybrid': Polygon and line elements are rendered as images, so pixels are scaled during zoom animations. Point symbols and texts are accurately rendered as vectors and can stay upright on rotated views.
• 'vector': Everything is rendered as vectors. Use this mode for improved performance on vector tile layers with only a few rendered features (e.g. for highlighting a subset of features of another layer with the same source).

renderOrder

• renderOrder: OrderFunction

Render order. Function to be used when sorting features before rendering. By default features are drawn in the order that they are created. Use null to avoid the sort, but get an undefined draw order.

source

• source: string

If your style uses more than one source, you need to use either the source property or the layers property to limit rendering to a single vector source. The source property corresponds to the id of a vector source in your Mapbox style.

styleUrl

• styleUrl: string

The URL of the Mapbox style object to use for this layer. For a style created with Mapbox Studio and hosted on Mapbox, this will look like 'mapbox://styles/you/your-style'.

updateWhileAnimating

• updateWhileAnimating: boolean

When set to true, feature batches will be recreated during animations. This means that no vectors will be shown clipped, but the setting will have a performance impact for large amounts of vector data. When set to false, batches will be recreated when no animation is active.

updateWhileInteracting

• updateWhileInteracting: boolean

When set to true, feature batches will be recreated during interactions. See also updateWhileAnimating.

useInterimTilesOnError

• useInterimTilesOnError: boolean

Use interim tiles on error.

visible

• visible: boolean

Visibility.

zIndex

• zIndex: number

The z-index for layer rendering. At rendering time, the layers will be ordered, first by Z-index and then by position. When undefined, a zIndex of 0 is assumed for layers that are added to the map's layers collection, or Infinity when the layer's setMap() method was used.

Interface: Options<>

.Options

Table of contents

Properties

• accessToken
• accessTokenParam
• getImage
• projection
• resolutions
• styleUrl
• transformRequest

Properties

accessToken

• accessToken: string

Access token for 'mapbox://' urls.

accessTokenParam

• accessTokenParam: string

Access token param. For internal use.

getImage

• getImage: (arg0: VectorLayer<any> | VectorTileLayer, arg1: string) => string | HTMLCanvasElement | HTMLImageElement

Type declaration

▸ (arg0, arg1): string | HTMLCanvasElement | HTMLImageElement

Function that returns an image for an icon name. If the result is an HTMLImageElement, it must already be loaded. The layer can be used to call layer.changed() when the loading and processing of the image has finished. This function be used for icons not in the sprite or to override sprite icons.

Parameters

Returns

string | HTMLCanvasElement | HTMLImageElement

projection

• projection: string

Only useful when working with non-standard projections. Code of a projection registered with OpenLayers. All sources of the style must be provided in this projection. The projection must also have a valid extent defined, which will be used to determine the origin and resolutions of the tile grid for all tiled sources of the style. When provided, the bbox placeholder in tile and geojson urls changes: the default is {bbox-epsg-3857}, when projection is e.g. set to EPSG:4326, the bbox placeholder will be {bbox-epsg-4326}.

resolutions

• resolutions: number[]

Only useful when working with non-standard projections. Resolutions for mapping resolution to the zoom used in the Mapbox style.

styleUrl

• styleUrl: string

URL of the Mapbox GL style. Required for styles that were provided as object, when they contain a relative sprite url, or sources referencing data by relative url.

transformRequest

• transformRequest: (arg0: string, arg1: ResourceType) => void | Request

Type declaration

▸ (arg0, arg1): void | Request

Function for controlling how ol-mapbox-style fetches resources. Can be used for modifying the url, adding headers or setting credentials options. Called with the url and the resource type as arguments, this function is supposed to return a Request object. Without a return value, the original request will not be modified. For Tiles and GeoJSON resources, only the url of the returned request will be respected.

Parameters

Returns

void | Request

Module: <internal>

Table of contents

Interfaces

• ApplyStyleOptions
• FeatureIdentifier
• Options
• Options

Type Aliases

• ResourceType

Type Aliases

ResourceType

Ƭ ResourceType<>: "Style" | "Source" | "Sprite" | "SpriteImage" | "Tiles" | "GeoJSON"