Dragonfly docs | GeoBuffer

Styles

Dragonfly Style Specification

A Dragonfly style is a document that defines the visual appearance of a map: what data to draw, the order to draw it in, and how to style the data when drawing it. A style document is a JSON object with specific root level and nested properties. This specification defines and describes these properties.

Root properties

Root level properties of a Dragonfly style specify the map's layers, tile sources and other resources, and default values for the initial camera position when not specified elsewhere.

{
    "version": 8,
    "name": "SocialExplorer Map",
    "sprite": "https://socialexplorer.com/sprite/sprite",
    "glyphs": "socex://fonts/{fontstack}/{range}.pbf",
    "sources": {...},
    "layers": [...]
}

version

Required enum.

Must be 8.

 "version": 8

name

Optional string.

A humane readable name for the style.

 "name": "StyleName"

center

Optional array of numbers.

Default map center in longitude and latitude. The style center will be used only if the map has not been positioned by other means (e.g. map options or user interaction).

"center": [
          -122.4194,
          37.7749
          ]

zoom

Optional number.

Default zoom level. The style zoom will be used only if the map has not been positioned by other means (e.g. map options or user interaction).

 "zoom": 12.5

bearing

Optional number. Units in degrees. Defaults to 0.

Default bearing, in degrees. The bearing is the compass direction that is "up"; for example, a bearing of 90° orients the map so that east is up. This value will be used only if the map has not been positioned by other means (e.g. map options or user interaction).

 "bearing": 29

pitch

Optional number. Units in degrees. Defaults to 0.

Default pitch, in degrees. Zero is perpendicular to the surface, for a look straight down at the map, while a greater value like 60 looks ahead towards the horizon. The style pitch will be used only if the map has not been positioned by other means (e.g. map options or user interaction).

 "pitch": 50

light

Optional light

The global light source.

"light": {
  "anchor": "viewport",
  "color": "white",
  "intensity": 0.4
}

sources

Required object with souce values.

Data source specifications. Defining layers here is necessary before using them in the layer styles.

"sources": {
  "source-layer-1": {
    ...
  }
}

sprite

Optional string.

A base URL for retrieving the sprite image and metadata. The extensions .png, .json and scale factor @2x.png will be automatically appended. This property is required if any layer uses the background-pattern, fill-pattern, line-pattern, fill-extrusion-pattern, or icon-image properties.

"sprite": "https://socialexplorer.com/sprite/sprite"

glyphs

Optional string.

A URL template for loading signed-distance-field glyph sets in PBF format. The URL must include {fonststack} and {range} tokens. This property is required if any layer uses text-field property.

"glyphs": "socex://fonts/{fontstack}/{range}.pbf"

transition

Optional transition.

A global transition definition to use as a default across properties.

"transition": {
  "duration": 300,
  "delay": 0
}

layers

Required array of layers.

Layers will be drawn in order of this array.

"layers": [
  {
    "id": "water",
    "source": "source-1",
    "source-layer": "water",
    "type": "fill",
    "paint": {
      "fill-color": "#00ffff"
    }
  }
]

Light

A style's light property provides global light source for that style.

"light": {
  "anchor": "viewport",
  "color": "white",
  "intensity": 0.4
}

anchor

Optional enum. One of "map","viewport". Defaults to "viewport"

Whether extruded geometries are lit relative to the map or viewport.

"map" The position of the light source is aligned to the rotation of the map.
"viewport" The position of the light source is aligned to the rotation of the viewport.

"anchor": "map"

position

Optional array of numbers. Defaults to [1.15,210,30]. Supports interpolate expresions. Transitionable

Position of the light source relative to lit (extruded) geometries, in [r radial coordinate, a azimuthal angle, p polar angle] where r indicates the distance from the center of the base of an object to its light, a indicates the position of the light relative to 0° (0° when light.anchor is set to viewport corresponds to the top of the viewport, or 0° when light.anchor is set to map corresponds to due north, and degrees proceed clockwise), and p indicates the height of the light (from 0°, directly above, to 180°, directly below).

Sources

Sources supply data to be shown on the map. The type of source is specified by the"type" property, and must be one of vector, raster, geojson, image, video. Adding a source won't immediately make data appear on the map because sources don't contain styling details like color or width. Layers refer to a source and give it a visual representation. This makes it possible to style the same source in different ways, like differentiating between types of roads in a highways layer. Tiled sources (vector and raster) must specify their details in terms of the TileJSON specification.

This can be done in several ways:

By supplying TileJSON properties such as "tiles", "minzoom", and"maxzoom" directly in the source:

"source-1": {
    "type": "vector",
    "tiles": [
    "http://a.example.com/tiles/{z}/{x}/{y}.pbf",
    "http://b.example.com/tiles/{z}/{x}/{y}.pbf"
    ],
    "maxzoom": 14
}

By providing a "url" to a TileJSON resource:

"source-1": {
    "type": "vector",
    "url": "http://api.example.com/tilejson.json"
}

vector

A vector tile source. Tiles must be in Mapbox Vector Tile format. All geometric coordinates in vector tiles must be between -1 * extent and (extent * 2) - 1 inclusive. All layers that use a vector source must specify a "source-layer"value. For vector tiles hosted by Mapbox, the "url" value should be of the form mapbox://mapid. For GeoBuffer hosted vector tiles the field "tiles" must be populated with the GeoBuffer tile delivery url signature.

'source-1': {
     "type": 'vector',
     "tiles": ['https://tiles3.socialexplorer.com/gettile/?x={x}&y={y}&z={z}&layers={layers}&projection=EPSG-3857&columns={columns}'],
     "layers": [
         {
             "layerId": "27238" // world landmass layer
         }
     ]
 }

url

Optional string.

A URL to a TileJSON resource. Supported protocols are http:, https:, and mapbox://<mapid>.

tiles

Optional array of strings.

An array of one or more tile source URLs, as in the TileJSON spec.

layers

Optional array of source layers.

List of GeoBuffer layers. This field is required when using GeoBuffer vector tiles. layerId is the Id from GeoBuffer tile layer. datasets is an array of data sets with the needed columns list.

"layers": [ // define layers that will be used
     {
         "layerId": "27238" // world landmass layer
     },
     {
         "layerId": "33174", // state boundaries layer
     },
     {
         // state boundaries layer transformed to a centroid point layer
         // by appending character "p" to the layerId
         "layerId": "33174p",
         "datasets": [
             {
                 "datasetId": 0,
                 "columns": [
                     "NAME",
                     "STUSPS",
                 ]
             }
         ]
     },
 ]

By appending special character p to the source layer id it is possible to request GeoBuffer to transform a polygon layer to a centroid point layer without the need to use a separate source. This can be useful in cases such as placing countries name labels.

Dataset with the id 0 is the default dataset that is created for each GeoBuffer Geo layer. In case a GeoBuffer Geo layer has mulitple Data tile layers linked it is necessary to select the one with the data we need to show on the map.

Array of columns represent the names of columns from the GeoBuffer source that are going to be used. It is also possible to define new columns on the fly by using the computed columns option which allows us to apply arithmetic or logical operations to an existing column.

"layers": [ // define layers that will be used
     {
         "layerId": "774",
         "datasets": [
             {
                 "datasetId": 0,
                 "columns": [
                     "POPULATION",
                     "POPULATION_IN_MILIONS -> {POPULATION}/1000000",  // computed column
                 ]
             }
         ]
     },
 ]

In case the dataset field is omitted only the geographical data will be delivered.

bounds

Optional array of numbers. Defaults to [-180, -85.0511. 180, 85.0511].

An array containing the longitude and latitude of the southwest and northeast corners of the source's bounding box in the following order: [sw.lng, sw.lat, ne.lng, ne.lat]. When this property is included in a source, no tiles outside of the given bounds are requested by Dragonfly.

minzoom

Optional number. Defaults to 0.

Minimum zoom level for which tiles are available, as in the TileJSON spec.

maxzoom

Optional number. Defaults to 22.

Maximum zoom level for which tiles are available, as in the TileJSON spec. Data from tiles at the maxzoom are used when displaying the map at higher zoom levels.

attribution

Optional string.

Contains an attribution to be displayed when the map is shown to a user.

raster

A raster tile source. For raster tiles hosted by Mapbox, the "url" value should be of the form mapbox://mapid.

"mapbox-satellite": {
    "type": "raster",
    "url": "mapbox://mapbox.satellite",
    "tileSize": 256
}

url

Optional string.

A URL to a TileJSON resource. Supported protocols are http:, https:, and mapbox://<mapid>.

tiles

Optional array of strings.

An array of one or more tile source URLs, as in the TileJSON spec.

bounds

Optional array of numbers. Defaults to [-180, -85.0511. 180, 85.0511].

minzoom

Optional number. Defaults to 0.

Minimum zoom level for which tiles are available, as in the TileJSON spec.

maxzoom

Optional number. Defaults to 22.

Maximum zoom level for which tiles are available, as in the TileJSON spec. Data from tiles at the maxzoom are used when displaying the map at higher zoom levels.

tilesize

Optional number. Units in pixels. Defaults to 512.

The minimum visual size to display tiles for this layer. Only configurable for raster layers.

scheme

Optional enum. One of "xyz", "tms". Defaults to "xyz".

Influences the y direction of the tile coordinates. The global-mercator (aka Spherical Mercator) profile is assumed.

"xyz" Slippy map tilenames scheme.
"tms" SGeo spec scheme.

attribution

Optional string.

Contains an attribution to be displayed when the map is shown to a user.

geojson

A GeoJSON source. Data must be provided via a "data"property, whose value can be a URL or inline GeoJSON.

"geojson-marker": {
    "type": "geojson",
    "data": {
        "type": "Feature",
        "geometry": {
            "type": "Point",
            "coordinates": [-122.4194, 37.7749]
        },
        "properties": {
            "title": "San Francisco",
            "marker-symbol": "monument"
        }
    }
}

This example of a GeoJSON source refers to an external GeoJSON document via its URL. The GeoJSON document must be on the same domain or accessible using CORS.

"geojson-lines": {
    "type": "geojson",
    "data": "./lines.geojson"
}

data

Optional.

A URL to a GeoJSON file, or inline GeoJSON.

maxzoom

Optional number. Defaults to 18.

Maximum zoom level at which to create vector tiles (higher means greater detail at high zoom levels).

buffer

Optional number between 0 and 512. Defaults to 128.

Size of the tile buffer on each side. A value of 0 produces no buffer. A value of 512 produces a buffer as wide as the tile itself. Larger values produce fewer rendering artifacts near tile edges and slower performance.

tolerance

Optional array of numbers. Defaults to 0.375.

Douglas-Peucker simplification tolerance (higher means simpler geometries and faster performance).

cluster

Optional boolean. Defaults to false.

If the data is a collection of point features, setting this to true clusters the points by radius into groups.

clusterRadius

Optional number greater than or equal to 0. Defaults to 50.

Radius of each cluster if clustering is enabled. A value of 512 indicates a radius equal to the width of a tile.

clusterMaxZoom

Optional number.

Max zoom on which to cluster points if clustering is enabled. Defaults to one zoom less than maxzoom (so that last zoom features are not clustered).

lineMetrics

Optional boolean. Defaults to false.

Whether to calculate line distance metrics. This is required for line layers that specify line-gradient values.

image

An image source. The "url" value contains the image location.

The "coordinates" array contains [longitude, latitude] pairs for the image corners listed in clockwise order: top left, top right, bottom right, bottom left.

"image": {
    "type": "image",
    "url": "assets/images/map.jpg",
    "coordinates": [
        [-80.425, 46.437],
        [-71.516, 46.437],
        [-71.516, 37.936],
        [-80.425, 37.936]
    ]
}

url

Required string.

URL that points to an image.

coordinates

Required array of array of numbers.

Corners of image specified in longitude, latitude pairs.

video

A video source. The "urls" value is an array. For each URL in the array, a video element source will be created, in order to support same media in multiple formats supported by different browsers.

The "coordinates" array contains [longitude, latitude] pairs for the video corners listed in clockwise order: top left, top right, bottom right, bottom left.

"video": {
    "type": "video",
    "urls": [
        "assets/videos/SocialExplorerDemo.webm"
    ],
    "coordinates": [
        [-122.51596391201019, 37.56238816766053],
        [-122.51467645168304, 37.56410183312965],
        [-122.51309394836426, 37.563391708549425],
        [-122.51423120498657, 37.56161849366671]
    ]
}

urls

Required string.

URLs to video content in order of preferred format.

coordinates

Required array of array of numbers.

Corners of video specified in longitude, latitude pairs.

Sprite

A style's sprite property supplies a URL template for loading small images to use in rendering background-pattern, fill-pattern, line-pattern, and icon-image style properties.

"sprite": "https://socialexplorer.com/sprite/sprite"

A valid sprite source must supply two types of files:

An index file, which is a JSON document containing a description of each image contained in the sprite. The content of this file must be a JSON object whose keys form identifiers to be used as the values of the above style properties, and whose values are objects describing the dimensions (width and height properties) and pixel ratio (pixelRatio) of the image and its location within the sprite (x and y). For example, a sprite containing a single image might have the following index file contents:
```
{
    "poi": {
        "width": 32,
        "height": 32,
        "x": 0,
        "y": 0,
        "pixelRatio": 1
    }
}
```
Then the style could refer to this sprite image by creating a symbol layer with the layout property"icon-image": "poi", or with the tokenized value "icon-image": "{icon}" and vector tile features with a icon property with the value poi.
Image files, which are PNG images containing the sprite data.

Dragonfly SDKs will use the value of the sprite property in the style to generate the URLs for loading both files. First, for both file types, it will append @2x to the URL on high-DPI devices. Second, it will append a file extension: .json for the index file, and .png for the image file. For example, if you specified "sprite": "https://example.com/sprite", renderers would load https://example.com/sprite.json and https://example.com/sprite.png, or https://example.com/sprite@2x.json and https://example.com/sprite@2x.png.

Glyphs

A style's glyphs property provides a URL template for loading signed-distance-field glyph sets in PBF format.

"glyphs": "socex://fonts/{fontstack}/{range}.pbf"

This URL template should include two tokens:

{fontstack} When requesting glyphs, this token is replaced with a comma separated list of fonts from a font stack specified in the text-font property of a symbol layer.
{range} When requesting glyphs, this token is replaced with a range of 256 Unicode code points. For example, to load glyphs for the Unicode Basic Latin and Basic Latin-1 Supplement blocks, the range would be 0-255. The actual ranges that are loaded are determined at runtime based on what text needs to be displayed.

Transition

A style's transition property provides global transition defaults for that style.

"transition": {
    "duration": 300,
    "delay": 0
}

Optional number greater than or equal to 0. Units in miliseconds. Defaults to 300.

Time allotted for transitions to complete.

"anchor": "map"

Optional number greater than or equal to 0. Units in miliseconds. Defaults to 0.

Length of time before a transition begins.

Layers

A style's layers property lists all of the layers available in that style. The type of layer is specified by the "type" property, and must be one of background, fill, line, symbol, raster, circle, fill-extrusion, heatmap, dotdensity.

Except for layers of the background type, each layer needs to refer to a source. Layers take the data that they get from a source, optionally filter features, and then define how those features are styled.

"layers": [
  {
    "id": "water",
    "source": "source-1",
    "source-layer": "water",
    "type": "fill",
    "paint": {
      "fill-color": "#00ffff"
    }
  }
]

id

Required string.

Unique layer name.

type

Required enum. One of "background","fill","line","symbol", "circle","heatmap","fill-extrusion","raster", "dotdensity"

Rendering type of this layer.

"fill" A filled polygon with an optional stroked border.
"line" A stroked line
"symbol" An icon or a text label.
"circle" A filled circle.
"heatmap" A heatmap.
"fill-extrusion" An extruded (3D) polygon.
"raster" Raster map textures such as satellite imagery.
"background" The background color or pattern of the map.
"dotdensity" A dotdensity map.

metadata

Optional.

Arbitrary properties useful to track with the layer, but do not influence rendering. Properties should be prefixed to avoid collisions, like 'mapbox:'.

source

Optional string.

Name of a source description to be used for this layer. Required for all layer types except background.

source-layer

Optional string.

Layer to use from a vector tile source. Required for vector tile sources; prohibited for all other source types, including GeoJSON sources.

auto-source

Optional array of sources.

Using auto-source property it is possible to define different source layers depending on map zoom level.

"auto-source": [
     { // for zoom levels between 1 and 5 use source layer with the id 69278
         "type": "fill",
         "id": "SL040",
         "source": "source-1",
         "minzoom": 1,
         "maxzoom": 5,
         "source-layer": "69278"

     },
     { // for zoom levels between 5 and 9 use source layer with the id 35172
         "type": "fill",
         "id": "SL050",
         "source": "source-1",
         "minzoom": 5,
         "maxzoom": 9,
         "source-layer": "35172"
}]

minzoom

Optional number between 0 and 24 inclusive.

The minimum zoom level for the layer. At zoom levels less than the minzoom, the layer will be hidden.

maxzoom

Optional number between 0 and 24 inclusive.

The maximum zoom level for the layer. At zoom levels equal to or greater than the maxzoom, the layer will be hidden.

filter

Optional expresion.

A expression specifying conditions on source features. Only features that match the filter are displayed.

layout

Optional layout.

Layout properties for the layer.

paint

Optional paint.

Default paint properties for this layer.

Layers have two sub-properties that determine how data from that layer is rendered: layout and paint properties.

Layout properties appear in the layer's "layout" object. They are applied early in the rendering process and define how data for that layer is passed to the GPU. Changes to a layout property require an asynchronous "layout" step.

Paint properties are applied later in the rendering process. Paint properties appear in the layer's"paint" object. Changes to a paint property are cheap and happen synchronously.

background

visibility

Layout property. Optional enum. One of "visible", "none". Defaults to "visible".

Whether this layer is displayed.

"visible" The layer is shown.
"none" The layer is not shown

background-color

Paint property. Optional color. Defaults to "000000". Disabled by background-pattern. Supports interpolate expressions. Transitionable.

The color with which the background will be drawn.

background-pattern

Paint property. Optional string. Transitionable.

Name of image in sprite to use for drawing an image background. For seamless patterns, image width and height must be a factor of two (2, 4, 8, ..., 512). Note that zoom-dependent expressions will be evaluated only at integer zoom levels.

background-opacity

Paint property. Optional number between 0 and 1 inclusive. Defaults to 1. Supports interpolate expressions. Transitionable.

The opacity at which the background will be drawn.

fill

visibility

Layout property. Optional enum. One of "visible", "none". Defaults to "visible".

Whether this layer is displayed.

"visible" The layer is shown.
"none" The layer is not shown

fill-antialias

Paint property. Optional boleean. Defaults to true. Data-driven styling not supported.

Whether or not the fill should be antialiased.

fill-opacity

Paint property. Optional number between 0 and 1 inclusive. Defaults to 1. Supports interpolate expressions. Transitionable. Data-driven styling supported.

The opacity of the entire fill layer. In contrast to the fill-color, this value will also affect the 1px stroke around the fill, if the stroke is used.

fill-color

Paint property. Optional color. Defaults to "000000". Disabled by background-pattern. Supports interpolate expressions. Transitionable. Data-driven styling supported.

The color of the filled part of this layer. This color can be specified as rgba with an alpha component and the color's opacity will not affect the opacity of the 1px stroke, if it is used.

fill-outline-color

Paint property. Optional color. Defaults to "000000". Disabled by fill-pattern. Requires fill-antialias. Supports interpolate expressions. Transitionable. Data-driven styling supported.

The outline color of the fill. Matches the value of fill-color if unspecified

fill-translate

Paint property. Optional array of numbers. Units in pixels. Defaults to [0,0] Supports interpolate expressions. Transitionable. Data-driven styling not supported.

The geometry's offset. Values are [x, y] where negatives indicate left and up, respectively.

fill-translate-anchor

Paint property. Optional enum. One of "map", "viewport" Defaults to "map". Requires fill-translate. Data-driven styling not supported.

Controls the frame of reference for fill-translate.

"map" The fill is translated relative to the map.
"viewport" The fill is translated relative to the viewport.

fill-pattern

Paint property. Optional string. Transitionable. Data-driven styling not supported.

Name of image in sprite to use for drawing image fills. For seamless patterns, image width and height must be a factor of two (2, 4, 8, ..., 512). Note that zoom-dependent expressions will be evaluated only at integer zoom levels.

line

line-cap

Layout property. Optional enum. One of "butt", "round", "square". Defaults to "butt". Data-driven styling not supported.

The display of line endings.

"butt" A cap with a squared-off end which is drawn to the exact endpoint of the line.
"round" A cap with a rounded end which is drawn beyond the endpoint of the line at a radius of one-half of the line's width and centered on the endpoint of the line.
"square" A cap with a squared-off end which is drawn beyond the endpoint of the line at a distance of one-half of the line's width.

line-join

Layout property. Optional enum. One of "bevel", "round", "miter". Defaults to "miter". Data-driven styling supported.

The display of lines when joining.

"bevel" A join with a squared-off end which is drawn beyond the endpoint of the line at a distance of one-half of the line's width.
"round" A join with a rounded end which is drawn beyond the endpoint of the line at a radius of one-half of the line's width and centered on the endpoint of the line.
"miter" A join with a sharp, angled corner which is drawn with the outer sides beyond the endpoint of the path until they meet.

line-miter-limit

Layout property. Optional number. Defaults to 2. Requires line-join to be miter. Supports interpolate expressions. Data-driven styling not supported.

Used to automatically convert miter joins to bevel joins for sharp angles.

line-round-limit

Layout property. Optional number. Defaults to 1.05. Requires line-join to be round. Supports interpolate expressions. Data-driven styling not supported.

Used to automatically convert round joins to miter joins for shallow angles.

visibility

Layout property. Optional enum. One of "visible", "none". Defaults to "visible". Data-driven styling not supported.

Whether this layer is displayed.

"visible" The layer is shown.
"none" The layer is not shown

line-opacity

Paint property. Optional number between 0 and 1 inclusive. Defaults to 1. Supports interpolate expressions. Transitionable. Data-driven styling supported.

The opacity at which the line will be drawn.

line-color

Paint property. Optional color. Defaults to "000000". Disabled by line-pattern. Supports interpolate expressions. Transitionable. Data-driven styling supported.

The color with which the line will be drawn.

line-translate

Paint property. Optional array of numbers. Units in pixels. Defaults to [0,0]. Supports interpolate expressions. Transitionable. Data-driven styling not supported.

The geometry's offset. Values are [x, y] where negatives indicate left and up, respectively.

line-translate-anchor

Paint property. Optional enum. One of "map", "viewport". Defaults to "map". Requires line-translate. Data-driven styling not supported.

Controls the frame of reference for line-translate.

"map" The line is translated relative to the map.
"viewport" The line is translated relative to the viewport.

line-width

Paint property. Optional number greater than or equal to 0. Units in pixels. Defaults to 1. Supports interpolate expressions. Transitionable. Data-driven styling supported.

Stroke thickness.

line-gap-width

Paint property. Optional number greater than or equal to 0. Units in pixels. Defaults to 0. Supports interpolate expressions. Transitionable. Data-driven styling supported.

Draws a line casing outside of a line's actual path. Value indicates the width of the inner gap.

line-offset

Paint property. Optional number. Units in pixels. Defaults to 0. Supports interpolate expressions. Transitionable. Data-driven styling supported.

Draws a line casing outside of a line's actual path. Value indicates the width of the inner gap.

line-blur

Paint property. Optional number greater than or equal to 0. Units in pixels. Defaults to 0. Supports interpolate expressions. Transitionable. Data-driven styling supported.

Blur applied to the line, in pixels.

line-dasharray

Paint property. Optional array of numbers number greater than or equal to 0. Units in line widths. Disabled by line-pattern. Transitionable. Data-driven styling not supported.

Specifies the lengths of the alternating dashes and gaps that form the dash pattern. The lengths are later scaled by the line width. To convert a dash length to pixels, multiply the length by the current line width. Note that GeoJSON sources with lineMetrics: true specified won't render dashed lines to the expected scale. Also note that zoom-dependent expressions will be evaluated only at integer zoom levels.

line-pattern

Paint property. Optional string. Transitionable. Data-driven styling supported.

Name of image in sprite to use for drawing image lines. For seamless patterns, image width and height must be a factor of two (2, 4, 8, ..., 512). Note that zoom-dependent expressions will be evaluated only at integer zoom levels.

line-gradient

Paint property. Optional color. Disabled by line-dasharray. Disabled by line-pattern. Requires source to be geojson. Data-driven styling supported.

Defines a gradient with which to color a line feature. Can only be used with GeoJSON sources that specify "lineMetrics": true.

symbol

symbol-placement

Layout property. Optional enum. One of "point", "line" Defaults to "point". Data-driven styling not supported.

Label placement relative to its geometry.

"point" The label is placed at the point where the geometry is located.
"line" The label is placed along the line of the geometry. Can only be used on LineString and Polygon geometries.

symbol-spacing

Layout property. Optional number greater than or equal to 1. Units in pixels. Defaults to 250. Supports interpolate expressions. Data-driven styling not supported.

Distance between two symbol anchors.

symbol-avoid-edges

Layout property. Optional boolean. Defaults to false. Data-driven styling not supported.

If true, the symbols will not cross tile edges to avoid mutual collisions. Recommended in layers that don't have enough padding in the vector tile to prevent collisions, or if it is a point symbol layer placed after a line symbol layer.

icon-allow-overlap

Layout property. Optional boolean. Defaults to false. Requires icon-image. Data-driven styling not supported.

If true, the icon will be visible even if it collides with other previously drawn symbols.

icon-ignore-placement

Layout property. Optional boolean. Defaults to false. Requires icon-image. Data-driven styling not supported.

If true, other symbols can be visible even if they collide with the icon.

icon-optional

Layout property. Optional boolean. Defaults to false. Requires icon-image. Requires text-field. Data-driven styling not supported.

If true, text will display without their corresponding icons when the icon collides with other symbols and the text does not.

icon-rotation-alignment

Layout property. Optional enum. One of "map", "viewport", "auto" Defaults to "auto". Requires icon-image. Data-driven styling not supported.

In combination with symbol-placement, determines the rotation behavior of icons.

"map" When symbol-placement is set to point, aligns icons east-west. When symbol-placement is set to line, aligns icon x-axes with the line.
"viewport" Produces icons whose x-axes are aligned with the x-axis of the viewport, regardless of the value of symbol-placement.
"auto" When symbol-placement is set to point, this is equivalent to viewport. When symbol-placement is set to line, this is equivalent to map.

icon-size

Layout property. Optional number greater than or equal to 0. Units in factor of the original icon size. Defaults to 1. Requires icon-image. Supports interpolate expressions. Data-driven styling supported.

Scales the original size of the icon by the provided factor. The new pixel size of the image will be the original pixel size multiplied by icon-size. 1 is the original size; 3 triples the size of the image.

icon-text-fit

Layout property. Optional enum. One of "none", "width", "width", "both" Defaults to "none". Requires icon-image. Requires text-fild. Data-driven styling not supported.

Scales the icon to fit around the associated text.

"none" The icon is displayed at its intrinsic aspect ratio.
"width" The icon is scaled in the x-dimension to fit the width of the text.
"height" The icon is scaled in the y-dimension to fit the height of the text.
"both" The icon is scaled in both x- and y-dimensions.

icon-text-fit-padding

Layout property. Optional array of numbers. Units in pixels. Defaults to [0,0,0,0]. Requires icon-image. Requires text-field. Requires icon-text-fit to be both, or width or height. Supports interpolate expressions. Data-driven styling not supported.

Size of the additional area added to dimensions determined by icon-text-fit, in clockwise order: top, right, bottom, left.

icon-image

Layout property. Optional string. Data-driven styling supported.

Name of image in sprite to use for drawing an image background.

icon-rotate

Layout property. Optional number. Units in degrees. Defaults to 0. Requires icon-image. Supports interpolate expressions. Data-driven styling supported.

Rotates the icon clockwise.

icon-padding

Layout property. Optional number greater than or equal to 0. Units in pixels. Defaults to 2. Requires icon-image. Supports interpolate expressions. Data-driven styling not supported.

Size of the additional area around the icon bounding box used for detecting symbol collisions.

icon-keep-upright

Layout property. Optional boolean. Defaults to false. Requires icon-image. Requires icon-rotation-alignment to be map. Requires symbol-placement to be line. Data-driven styling not supported.

If true, the icon may be flipped to prevent it from being rendered upside-down.

icon-offset

Layout property. Optional array of numbers. Defaults to [0,0]. Requires icon-image. Supports interpolate expressions. Data-driven styling supported.

Offset distance of icon from its anchor. Positive values indicate right and down, while negative values indicate left and up. Each component is multiplied by the value of icon-size to obtain the final offset in pixels. When combined with icon-rotate the offset will be as if the rotated direction was up.

icon-anchor

Layout property. Optional enum. One of "center", "left", "right", "top","bottom","top-left", "top-right","bottom-left","bottom-right". Defaults to "center". Requires icon-image. Data-driven styling supported.

Part of the icon placed closest to the anchor.

"center" The center of the icon is placed closest to the anchor.
"left" The left side of the icon is placed closest to the anchor.
"right" The right side of the icon is placed closest to the anchor.
"top" The top of the icon is placed closest to the anchor.
"bottom" The bottom of the icon is placed closest to the anchor.
"top-left" The top left corner of the icon is placed closest to the anchor.
"top-right" The top right corner of the icon is placed closest to the anchor.
"bottom-left" The bottom left corner of the icon is placed closest to the anchor.
"bottom-right" The bottom right corner of the icon is placed closest to the anchor.

icon-pitch-alignment

Layout property. Optional enum. One of "map", "viewport", "auto" Defaults to "auto". Requires icon-image. Data-driven styling not supported.

Orientation of icon when map is pitched.

"map" The icon is aligned to the plane of the map.
"viewport" The icon is aligned to the plane of the viewport.
"auto" Automatically matches the value of icon-rotation-alignment.

text-pitch-alignment

Layout property. Optional enum. One of "map", "viewport", "auto". Defaults to "auto". Requires text-field. Data-driven styling not supported.

Orientation of text when map is pitched.

"map" The text is aligned to the plane of the map.
"viewport" The text is aligned to the plane of the viewport.
"auto" Automatically matches the value of text-rotation-alignment.

text-rotation-alignment

Layout property. Optional enum. One of "map", "viewport", "auto". Defaults to "auto". Requires text-field. Data-driven styling not supported.

In combination with symbol-placement, determines the rotation behavior of the individual glyphs forming the text.

"map" When symbol-placement is set to point, aligns text east-west. When symbol-placement is set to line, aligns text x-axes with the line.
"viewport" Produces glyphs whose x-axes are aligned with the x-axis of the viewport, regardless of the value of symbol-placement.
"auto" When symbol-placement is set to point, this is equivalent to viewport. When symbol-placement is set to line, this is equivalent to map.

text-field

Layout property. Optional string. Defaults to "". Data-driven styling supported.

Value to use for a text label.

text-font

Layout property. Optional array of strings. Defaults to ["Open Sans Regular","Arial Unicode MS Regular"]. Requires text-field. Data-driven styling supported.

Font stack to use for displaying text.

text-size

Layout property. Optional number greater than or equal to 0. Units in pixels. Defaults to 16. Requires text-field. Supports interpolate expressions. Data-driven styling supported.

Font size.

text-max-width

Layout property. Optional number greater than or equal to 0. Units in ems. Defaults to 10. Requires text-field. Supports interpolate expressions. Data-driven styling supported.

The maximum line width for text wrapping.

text-line-height

Layout property. Optional number greater than or equal to 0. Units in ems. Defaults to 1.2. Requires text-field. Supports interpolate expressions. Data-driven styling not supported.

Text leading value for mulit-line text.

text-letter-spacing

Layout property. Optional number greater than or equal to 0. Units in ems. Defaults to 0. Requires text-field. Supports interpolate expressions. Data-driven styling supported.

Text tracking amount.

text-justify

Layout property. Optional enum. One of "left", "center", "right" Defaults to "center". Requires text-field. Data-driven styling supported.

Text justification options.

"left" The text is aligned to the left.
"center" The text is centered.
"right" The text is aligned to the right.

text-anchor

Part of the text placed closest to the anchor.

"center" The center of the text is placed closest to the anchor.
"left" The left side of the text is placed closest to the anchor.
"right" The right side of the text is placed closest to the anchor.
"top" The top of the text is placed closest to the anchor.
"bottom" The bottom of the text is placed closest to the anchor.
"top-left" The top left corner of the text is placed closest to the anchor.
"top-right" The top right corner of the text is placed closest to the anchor.
"bottom-left" The bottom left corner of the text is placed closest to the anchor.
"bottom-right" The bottom right corner of the text is placed closest to the anchor.

text-max-angle

Layout property. Optional number. Units in degrees. Defaults to 45. Requires text-field. Requires symbol-placement to be line. Supports interpolate expressions. Data-driven styling not supported.

Maximum angle change between adjacent characters.

text-rotate

Layout property. Optional number. Units in degrees. Defaults to 0. Requires text-field. Supports interpolate expressions.

Rotates the text clockwise.

text-padding

Layout property. Optional number greater than or equal to 0. Units in pixels. Defaults to 2. Requires text-image. Supports interpolate expressions. Data-driven styling not supported.

Size of the additional area around the text bounding box used for detecting symbol collisions.

text-keep-upright

Layout property. Optional boolean. Defaults to true. Requires text-field. Requires text-rotation-alignment to be map. Requires symbol-placement to be line. Data-driven styling not supported.

If true, the text may be flipped vertically to prevent it from being rendered upside-down.

text-transform

Layout property. Optional enum. One of "none", "uppercase", "lowercase" Defaults to "none". Requires text-field. Data-driven styling supported.

Specifies how to capitalize text, similar to the CSS text-transform property.

"none" The text is not altered.
"uppercase" Forces all letters to be displayed in uppercase.
"lowercase" Forces all letters to be displayed in lowercase.

text-offset

Layout property. Optional array of numbers. Units in ems. Defaults to [0,0]. Requires text-field. Supports interpolate expressions. Data-driven styling supported.

Offset distance of text from its anchor. Positive values indicate right and down, while negative values indicate left and up.

text-allow-overlap

Layout property. Optional boolean. Defaults to false. Requires text-field. Data-driven styling not supported.

If true, the text will be visible even if it collides with other previously drawn symbols.

text-ignore-placement

Layout property. Optional boolean. Defaults to false. Requires text-field. Data-driven styling not supported.

If true, other symbols can be visible even if they collide with the text.

text-optional

Layout property. Optional boolean. Defaults to false. Requires text-field. Requires icon-image. Data-driven styling not supported.

If true, icons will display without their corresponding text when the text collides with other symbols and the icon does not.

visibility

Layout property. Optional enum. One of "visible", "none". Defaults to "visible". Data-driven styling not supported.

Whether this layer is displayed.

"visible" The layer is shown.
"none" The layer is not shown

icon-opacity

Paint property. Optional number between 0 and 1 inclusive. Defaults to 1. Supports interpolate expressions. Transitionable. Data-driven styling supported.

The opacity at which the icon will be drawn.

icon-color

Paint property. Optional color. Defaults to "000000". Requires icon-image. Supports interpolate expressions. Transitionable. Data-driven styling supported.

The color of the icon. This can only be used with sdf icons.

icon-helo-color

Paint property. Optional color. Defaults to rgba(0,0,0,0)". Requires icon-image. Supports interpolate expressions. Transitionable. Data-driven styling supported.

The color of the icon's helo. This can only be used with sdf icons.

icon-helo-width

Paint property. Optional number greater than or equal to 0. Units in pixels. Defaults to 0. Requires icon-image. Supports interpolate expressions. Transitionable. Data-driven styling supported.

Distance of halo to the icon outline

icon-helo-blur

Paint property. Optional number greater than or equal to 0. Units in pixels. Defaults to 0. Requires icon-image. Supports interpolate expressions. Transitionable. Data-driven styling supported.

Fade out the halo towards the outside.

icon-translate

Paint property. Optional array of numbers. Units in pixels. Defaults to [0,0]. Supports interpolate expressions. Transitionable. Data-driven styling not supported.

Distance that the icon's anchor is moved from its original placement. Positive values indicate right and down, while negative values indicate left and up.

icon-translate-anchor

Paint property. Optional enum. One of "map", "viewport". Defaults to "map". Requires icon-translate. Data-driven styling not supported.

Controls the frame of reference for icon-translate.

"map" The icon is translated relative to the map.
"viewport" The icon is translated relative to the viewport.

text-opacity

Paint property. Optional number between 0 and 1 inclusive. Defaults to 1. Requires text-field. Supports interpolate expressions. Transitionable. Data-driven styling supported.

The opacity at which the text will be drawn.

text-color

Paint property. Optional color. Defaults to "000000". Requires text-field. Supports interpolate expressions. Transitionable. Data-driven styling supported.

The color with which the text will be drawn.

text-helo-color

Paint property. Optional color. Defaults to rgba(0,0,0,0)". Requires text-field. Supports interpolate expressions. Transitionable. Data-driven styling supported.

The color of the text's helo.

text-helo-width

Paint property. Optional number greater than or equal to 0. Units in pixels. Defaults to 0. Requires text-field. Supports interpolate expressions. Transitionable. Data-driven styling supported.

Distance of halo to the font outline. Max text halo width is 1/4 of the font-size.

text-helo-blur

Paint property. Optional number greater than or equal to 0. Units in pixels. Defaults to 0. Requires text-field. Supports interpolate expressions. Transitionable. Data-driven styling supported.

The halo's fadeout distance towards the outside.

text-translate

Paint property. Optional array of numbers. Units in pixels. Defaults to [0,0]. Requires text-field. Supports interpolate expressions. Transitionable. Data-driven styling not supported.

Distance that the text's anchor is moved from its original placement. Positive values indicate right and down, while negative values indicate left and up.

text-translate-anchor

Paint property. Optional enum. One of "map", "viewport". Defaults to "map". Requires text-translate. Data-driven styling not supported.

Controls the frame of reference for text-translate.

"map" The text is translated relative to the map.
"viewport" The text is translated relative to the viewport.

Raster

visibility

Layout property. Optional enum. One of "visible", "none". Defaults to "visible". Data-driven styling not supported.

Whether this layer is displayed.

"visible" The layer is shown.
"none" The layer is not shown

raster-opacity

Paint property. Optional number between 0 and 1 inclusive. Defaults to 1. Supports interpolate expressions. Transitionable. Data-driven styling not supported.

The opacity at which the image will be drawn.

raster-hue-rotation

Paint property. Optional number. Units in degrees. Defaults to 0. Supports interpolate expressions. Transitionable.

raster-brightness-min

Paint property. Optional number between 0 and 1 inclusive. Defaults to 0. Supports interpolate expressions. Transitionable. Data-driven styling not supported.

Increase or reduce the brightness of the image. The value is the minimum brightness.

raster-brightness-max

Paint property. Optional number between 0 and 1 inclusive. Defaults to 1. Supports interpolate expressions. Transitionable. Data-driven styling not supported.

Increase or reduce the brightness of the image. The value is the maximum brightness.

raster-saturation

Paint property. Optional number between -1 and 1 inclusive. Defaults to 0. Supports interpolate expressions. Transitionable. Data-driven styling not supported.

Increase or reduce the saturation of the image.

raster-contrast

Paint property. Optional number between -1 and 1 inclusive. Defaults to 0. Supports interpolate expressions. Transitionable. Data-driven styling not supported.

Increase or reduce the contrast of the image.

raster-fade-duration

Paint property. Optional number greater than or equal to 0. Units in milliseconds. Defaults to 300. Supports interpolate expressions. Data-driven styling not supported.

Fade duration when a new title is added.

circle

visibility

Layout property. Optional enum. One of "visible", "none". Defaults to "visible".

Whether this layer is displayed.

"visible" The layer is shown.
"none" The layer is not shown

circle-radius

Paint property. Optional number greater than or equal to 0. Units in pixels. Defaults to 5. Supports interpolate expressions. Transitionable. Data-driven styling supported.

Circle radius.

circle-color

Paint property. Optional color. Defaults to "000000". Supports interpolate expressions. Transitionable. Data-driven styling supported.

The fill color of the circle.

circle-blur

Paint property. Optional number. Defaults to 0. Supports interpolate expressions. Transitionable. Data-driven styling supported.

Amount to blur the circle. 1 blurs the circle such that only the centerpoint is full opacity.

circle-opacity

Paint property. Optional number between 0 and 1 inclusive. Defaults to 1. Supports interpolate expressions. Transitionable. Data-driven styling supported.

The opacity at which the circle will be drawn.

circle-translate

Paint property. Optional array of numbers. Units in pixels. Defaults to [0,0]. Supports interpolate expressions. Transitionable. Data-driven styling not supported.

The geometry's offset. Values are [x, y] where negatives indicate left and up, respectively.

circle-translate-anchor

Paint property. Optional enum. One of "map", "viewport". Defaults to "map". Requires circle-translate. Data-driven styling not supported.

Controls the frame of reference for circle-translate.

"map" The circle is translated relative to the map.
"viewport" The circle is translated relative to the viewport.

circle-pitch-scale

Paint property. Optional enum. One of "map", "viewport". Defaults to "map". Data-driven styling not supported.

Controls the scaling behavior of the circle when the map is pitched.

"map" Circles are scaled according to their apparent distance to the camera.
"viewport" Circles are not scaled.

circle-pitch-alignment

Paint property. Optional enum. One of "map", "viewport". Defaults to "map". Data-driven styling not supported.

Orientation of circle when map is pitched.

"map" The circle is aligned to the plane of the map.
"viewport" The circle is aligned to the plane of the viewport.

circle-stroke-width

Paint property. Optional number greater than or equal to 0. Units in pixels. Defaults to 0. Supports interpolate expressions. Transitionable.

The width of the circle's stroke. Strokes are placed outside of the circle-radius.

circle-stroke-color

Paint property. Optional color. Defaults to "000000". Supports interpolate expressions. Transitionable. Data-driven styling supported.

The stroke color of the circle.

circle-stroke-opacity

Paint property. Optional number between 0 and 1 inclusive. Defaults to 1. Supports interpolate expressions. Transitionable. Data-driven styling supported.

The opacity of the circle's stroke.

fill-extrusion

visibility

Layout property. Optional enum. One of "visible", "none". Defaults to "visible".

Whether this layer is displayed.

"visible" The layer is shown.
"none" The layer is not shown

fill-extrusion-opacity

Paint property. Optional number between 0 and 1 inclusive. Defaults to 1. Supports interpolate expressions. Transitionable.

The opacity of the entire fill extrusion layer. This is rendered on a per-layer, not per-feature, basis, and data-driven styling is not available.

fill-extrusion-color

Paint property. Optional color. Defaults to "000000". Disabled by fill-extrusion-pattern. Supports interpolate expressions. Transitionable. Data-driven styling supported.

The base color of the extruded fill. The extrusion's surfaces will be shaded differently based on this color in combination with the root light settings. If this color is specified as rgba with an alpha component, the alpha component will be ignored; use fill-extrusion-opacity to set layer opacity.

fill-extrusion-translate

Paint property. Optional array of numbers. Units in pixels. Defaults to [0,0]. Supports interpolate expressions. Transitionable. Data-driven styling not supported.

The geometry's offset. Values are [x, y] where negatives indicate left and up, respectively.

fill-extrusion-translate-anchor

Paint property. Optional enum. One of "map", "viewport". Defaults to "map". Requires fill-extrusion-translate. Data-driven styling not supported.

Controls the frame of reference for fill-extrusion-translate.

"map" The fill-extrusion is translated relative to the map.
"viewport" The fill-extrusion is translated relative to the viewport.

fill-extrusion-pattern

Paint property. Optional string. Transitionable. Data-driven styling not supported.

Name of image in sprite to use for drawing images on extruded fills. For seamless patterns, image width and height must be a factor of two (2, 4, 8, ..., 512). Note that zoom-dependent expressions will be evaluated only at integer zoom levels.

fill-extrusion-height

Paint property. Optional number greater than or equal to 0 . Units in meters. Defaults to 0. Supports interpolate expressions. Transitionable. Data-driven styling supported.

The height with which to extrude this layer.

fill-extrusion-base

Paint property. Optional number greater than or equal to 0. Units in meters. Defaults to 0. Requires fill-extrusion-height. Supports interpolate expressions. Transitionable. Data-driven styling supported.

The height with which to extrude the base of this layer. Must be less than or equal to fill-extrusion-height.

heatmap

visibility

Layout property. Optional enum. One of "visible", "none". Defaults to "visible".

Whether this layer is displayed.

"visible" The layer is shown.
"none" The layer is not shown

heatmap-radius

Paint property. Optional number greater than or equal to 1. Units in pixels. Defaults to 30. Supports interpolate expressions. Transitionable. Data-driven styling supported.

Radius of influence of one heatmap point in pixels. Increasing the value makes the heatmap smoother, but less detailed.

heatmap-weight

Paint property. Optional number greater than or equal to 1. Defaults to 1. Supports interpolate expressions. Data-driven styling supported.

A measure of how much an individual point contributes to the heatmap. A value of 10 would be equivalent to having 10 points of weight 1 in the same spot. Especially useful when combined with clustering.

heatmap-intensity

Paint property. Optional number greater than or equal to 1. Defaults to 1. Supports interpolate expressions. Data-driven styling not supported.

Similar to heatmap-weight but controls the intensity of the heatmap globally. Primarily used for adjusting the heatmap based on zoom level.

heatmap-color

Paint property. Optional color. Defaults to ["interpolate",["linear"],["heatmap-density"],0,"rgba(0, 0, 255, 0)",0.1,"royalblue",0.3,"cyan",0.5,"lime",0.7,"yellow",1,"red"]. Supports interpolate expressions. Transitionable. Data-driven styling not supported.

Defines the color of each pixel based on its density value in a heatmap. Should be an expression that uses ["heatmap-density"] as input.

heatmap-opacity

Paint property. Optional number between 0 and 1 inclusive. Defaults to 1. Supports interpolate expressions. Transitionable. Data-driven styling not supported.

The opacity at which the heatmap layer will be drawn.

dotdensity

visibility

Layout property. Optional enum. One of "visible", "none". Defaults to "visible".

Whether this layer is displayed.

"visible" The layer is shown.
"none" The layer is not shown

dotdensity-count

Layout property. Required number. Supports interpolate exspressions. Data-driven styling supported.

The number of dots to be drawn. Feature properties are specified using tokens like "{field_name} * 2".

dotdensity-radius

Paint property. Optional number greater than or equal to 0. Units in pixels. Defaults to 3. Supports interpolate expressions. Transitionable. Data-driven styling supported.

Dot radius.

dotdensity-opacity

Paint property. Optional number between 0 and 1 inclusive. Defaults to 1. Supports interpolate expressions. Transitionable. Data-driven styling supported.

The opacity at which the dots will be drawn.

dotdensity-color

Paint property. Optional color. Defaults to "000000". Supports interpolate expressions. Transitionable. Data-driven styling supported.

The color with which the dots will be drawn.

dotdensity-blur

Paint property. Optional number. Defaults to 0. Supports interpolate expressions. Transitionable. Data-driven styling supported.

Amount to blur the dot. 1 blurs the dot such that only the centerpoint is full opacity.

bubble

visibility

Layout property. Optional enum. One of "visible", "none". Defaults to "visible".

Whether this layer is displayed.

"visible" The layer is shown.
"none" The layer is not shown

bubble-radius

Layout property. Required number. Supports interpolate exspressions. Data-driven styling supported.

Value to use for a radius calculation. Feature properties are specified using tokens like "{field_name} * 2".

bubble-radius-multiplier

Paint property. Optional number greater than 0. Defaults to 1 Supports interpolate exspressions.

The multiplier for the radius size (changing this is fast).

bubble-color

Paint property. Optional color. Defaults to "000000". Supports interpolate expressions. Transitionable. Data-driven styling supported.

The color of the bubble.

bubble-outline-color

Paint property. Optional color. Defaults to "000000". Supports interpolate expressions. Transitionable. Data-driven styling supported.

The color of the bubble's rim.

bubble-max-radius

Paint property. Optional number. Requires bubble-radius. Supports interpolate exspressions. Data-driven styling supported. Data-driven styling supported.

The max value for the radius size.

bubble-max-radius-outline-color

Paint property. Optional color. Defaults to "000000". Requires bubble-max-radius. Supports interpolate expressions. Transitionable. Data-driven styling supported.

The color of the bubble's rim when max radius reached.

bubble-max-radius-outline-width

Paint property. Optional number greater than or equal to 0. Units in pixels. Defaults to 1. Requires bubble-max-radius. Supports interpolate expressions. Transitionable. Data-driven styling supported.

The width of the bubble's rim when max radius reached.

bubble-outline-width

Paint property. Optional number greater than or equal to 0. Units in pixels. Defaults to 2. Supports interpolate expressions. Transitionable. Data-driven styling supported.

The width of the bubble's rim.

bubble-opacity

Paint property. Optional number between 0 and 1 inclusive. Defaults to 1. Supports interpolate expressions. Transitionable. Data-driven styling supported.

The opacity at which the bubbles will be drawn.

bubble-translate

Paint property. Optional array of numbers. Units in pixels. Defaults to [0,0]. Supports interpolate expressions. Transitionable. Data-driven styling not supported.

The geometry's offset. Values are [x, y] where negatives indicate left and up, respectively.

bubble-translate-anchor

Paint property. Optional enum. One of "map", "viewport". Defaults to "map". Requires bubble-translate. Data-driven styling not supported.

Controls the frame of reference for bubble-translate.

"map" The bubble is translated relative to the map.
"viewport" The bubble is translated relative to the viewport.

Color

The color type represents a color in the sRGB color space. Colors are written as JSON strings in a variety of permitted formats: HTML-style hex values, rgb, rgba, hsl, and hsla. Predefined HTML colors names, like yellow and blue, are also permitted.

{
    "line-color": "#ff0",
    "line-color": "#ffff00",
    "line-color": "rgb(255, 255, 0)",
    "line-color": "rgba(255, 255, 0, 1)",
    "line-color": "hsl(100, 50%, 50%)",
    "line-color": "hsla(100, 50%, 50%, 1)",
    "line-color": "yellow"
}

String

A string is basically just text.

{
    "icon-image": "marker"
}

Boolean

Boolean means yes or no, so it accepts the values true or false.

{
    "fill-enabled": true
}

Number

A number value, often an integer or floating point (decimal number). Written without quotes.

{
    "text-size": 24
}

Array

Arrays are comma-separated lists of one or more numbers in a specific order. For example, they're used in line dash arrays, in which the numbers specify intervals of line, break, and line again.

{
    "line-dasharray": [2, 4]
}

Expressions

The value for any layout property, paint property, or filter may be specified as an expression. An expression defines a formula for computing the value of the property using the operators described below. The set of expression operators provided by Dragonfly includes:

Mathematical operators for performing arithmetic and other operations on numeric values
Logical operators for manipulating boolean values and making conditional decisions
String operators for manipulating strings
Data operators, providing access to the properties of source features
Camera operators, providing access to the parameters defining the current map view

Expressions are represented as JSON arrays. The first element of an expression array is a string naming the expression operator, e.g. "*"or "case". Subsequent elements (if any) are the arguments to the expression. Each argument is either a literal value (a string, number, boolean, or null), or another expression array.

[expression_name, argument_0, argument_1, ...]

Data expressions

A data expression is any expression that access feature data -- that is, any expression that uses one of the data operators:get,has,id,geometry-type, or properties. Data expressions allow a feature's properties to determine its appearance. They can be used to differentiate features within the same layer and to create data visualizations.

{
    "circle-color": [
        "rgb",
        // red is higher when feature.properties.temperature is higher
        ["get", "temperature"],
        // green is always zero
        0,
        // blue is higher when feature.properties.temperature is lower
        ["-", 100, ["get", "temperature"]]
    ]
}

This example uses the get operator to obtain the temperature value of each feature. That value is used to compute arguments to the rgb operator, defining a color in terms of its red, green, and blue components.

Data expressions are allowed as the value of thefilter property, and as values for most paint and layout properties. However, some paint and layout properties do not yet support data expressions. The level of support is indicated by the "data-driven styling" row of the "SDK Support" table for each property.

Camera expressions

A camera expression is any expression that uses the zoom operator. Such expressions allow the the appearance of a layer to change with the map's zoom level. Camera expressions can be used to create the appearance of depth and to control data density.

{
    "circle-radius": [
        "interpolate", ["linear"], ["zoom"],
        // zoom is 5 (or less) -> circle radius will be 1px
        5, 1,
        // zoom is 10 (or greater) -> circle radius will be 5px
        10, 5
    ]
}

This example uses the interpolateoperator to define a linear relationship between zoom level and circle size using a set of input-output pairs. In this case, the expression indicates that the circle radius should be 1 pixel when the zoom level is 5 or below, and 5 pixels when the zoom is 10 or above. In between, the radius will be linearly interpolated between 1 and 5 pixels.

Camera expressions are allowed anywhere an expression may be used. However, when a camera expression used as the value of a layout or paint property, it must be in one of the following forms:

[ "interpolate", interpolation, ["zoom"], ... ]

Or:

[ "step", ["zoom"], ... ]

Or:

[
    "let",
    ... variable bindings...,
    [ "interpolate", interpolation, ["zoom"], ... ]
]

Or:

[
    "let",
    ... variable bindings...,
    [ "step", ["zoom"], ... ]
]

That is, in layout or paint properties, ["zoom"] may appear only as the input to an outer interpolate or step expression, or such an expression within a let expression.

There is an important difference between layout and paint properties in the timing of camera expression evaluation. Paint property camera expressions are re-evaluated whenever the zoom level changes, even fractionally. For example, a paint property camera expression will be re-evaluated continuously as the map moves between zoom levels 4.1 and 4.6. On the other hand, a layout property camera expression is evaluated only at integer zoom levels. It will not be re-evaluated as the zoom changes from 4.1 to 4.6 -- only if it goes above 5 or below 4.

Composition

A single expression may use a mix of data operators, camera operators, and other operators. Such composite expressions allows a layer's appearance to be determined by a combination of the zoom level and individual feature properties.

{
    "circle-radius": [
        "interpolate", ["linear"], ["zoom"],
        // when zoom is 0, set each feature's circle radius to the value of its "rating" property
        0, ["get", "rating"],
        // when zoom is 10, set each feature's circle radius to four times the value of its "rating" property
        10, ["*", 4, ["get", "rating"]]
    ]
}

An expression that uses both data and camera operators is considered both a data expression and a camera expression, and must adhere to the restrictions described above for both.

Type system

The input arguments to expressions, and their result values, use the same set of types as the rest of the style specification: boolean, string, number, color, and arrays of these types. Furthermore, expressions are type safe: each use of an expression has a known result type and required argument types, and the SDKs verify that the result type of an expression is appropriate for the context in which it is used. For example, the result type of an expression in the filter property must be boolean, and the arguments to the + operator must be numbers.

When working with feature data, the type of a feature property value is typically not known ahead of time by the SDK. In order to preserve type safety, when evaluating a data expression, the SDK will check that the property value is appropriate for the context. For example, if you use the expression ["get", "feature-color"] for the circle-color property, the SDK will verify that the feature-color value of each feature is a string identifying a valid color. If this check fails, an error will be indicated in an SDK-specific way (typically a log message), and the default value for the property will be used instead.

In most cases, this verification will occur automatically wherever it is needed. However, in certain situations, the SDK may be unable to automatically determine the expected result type of a data expression from surrounding context. For example, it is not clear whether the expression ["<", ["get", "a"], ["get", "b"]] is attempting to compare strings or numbers. In situations like this, you can use one of the type assertion expression operators to indicate the expected type of a data expression: ["<", ["number", ["get", "a"]], ["number", ["get", "b"]]]. A type assertion checks that the feature data actually matches the expected type of the data expression. If this check fails, it produces an error and causes the whole expression to fall back to the default value for the property being defined. The assertion operators are array, boolean, number, and string.

Expressions perform only one kind of implicit type conversion: a data expression used in a context where a color is expected will convert a string representation of a color to a color value. In all other cases, if you want to convert between types, you must use one of the type conversion expression operators: to-boolean, to-number, to-string, or to-color. For example, if you have a feature property that stores numeric values in string format, and you want to use those values as numbers rather than strings, you can use an expression such as ["to-number", ["get", "property-name"]].

Types

The expressions in this section are provided for the purpose of testing for and converting between different data types like strings, numbers, and boolean values.

Often, such tests and conversions are unnecessary, but they may be necessary in some expressions where the type of a certain sub-expression is ambiguous. They can also be useful in cases where your feature data has inconsistent types; for example, you could use to-number to make sure that values like "1.5" (instead of 1.5) are treated as numeric values.

array

Asserts that the input is an array (optionally with a specific item type and length). If, when the input expression is evaluated, it is not of the asserted type, then this assertion will cause the whole expression to be aborted.

["array", value]: array

["array", type: "string" | "number" | "boolean", value]: array<type>

["array",
    type: "string" | "number" | "boolean",
    N: number (literal),
    value
]: array<type, N>

boolean

Asserts that the input value is a boolean. If multiple values are provided, each one is evaluated in order until a boolean is obtained. If none of the inputs are booleans, the expression is an error.

["boolean", value]: boolean

["boolean", value, fallback: value, fallback: value, ...]: boolean

collator

Returns a collator for use in locale-dependent comparison operations. The case-sensitive and diacritic-sensitive options default to false. The locale argument specifies the IETF language tag of the locale to use. If none is provided, the default locale is used. If the requested locale is not available, the collator will use a system-defined fallback locale. Use resolved-locale to test the results of locale fallback behavior.

["collator",
    { "case-sensitive": boolean, "diacritic-sensitive": boolean, "locale": string }
]: collator

literal

Provides a literal array or object value.

["literal", [...] (JSON array literal)]: array<T, N>

["literal", {...} (JSON object literal)]: Object

number

Asserts that the input value is a number. If multiple values are provided, each one is evaluated in order until a number is obtained. If none of the inputs are numbers, the expression is an error.

["number", value]: number

["number", value, fallback: value, fallback: value, ...]: number

object

Asserts that the input value is an object. If multiple values are provided, each one is evaluated in order until an object is obtained. If none of the inputs are objects, the expression is an error.

["object", value]: object

["object", value, fallback: value, fallback: value, ...]: object

string

Asserts that the input value is a string. If multiple values are provided, each one is evaluated in order until a string is obtained. If none of the inputs are strings, the expression is an error.

["string", value]: string

["string", value, fallback: value, fallback: value, ...]: string

to-boolean

Converts the input value to a boolean. The result isfalsewhen then input is an empty string, 0, false, null, or NaN; otherwise it is true.

["to-boolean", value]: boolean

to-color

Converts the input value to a color. If multiple values are provided, each one is evaluated in order until the first successful conversion is obtained. If none of the inputs can be converted, the expression is an error.

["to-color", value, fallback: value, fallback: value, ...]: color

to-number

Converts the input value to a number, if possible. If the input is null or false, the result is 0. If the input is true, the result is 1. If the input is a string, it is converted to a number as specified by the "ToNumber Applied to the String Type" algorithm of the ECMAScript Language Specification. If multiple values are provided, each one is evaluated in order until the first successful conversion is obtained. If none of the inputs can be converted, the expression is an error.

["to-number", value, fallback: value, fallback: value, ...]: number

to-string

Converts the input value to a string. If the input is null, the result is "". If the input is a boolean, the result is "true" or "false". If the input is a number, it is converted to a string as specified by the "NumberToString" algorithm of the ECMAScript Language Specification. If the input is a color, it is converted to a string of the form "rgba(r,g,b,a)", where r, g, and b are numerals ranging from 0 to 255, and a ranges from 0 to 1. Otherwise, the input is converted to a string in the format specified by the JSON.stringify function of the ECMAScript Language Specification.

["to-string", value]: string

typeof

Returns a string describing the type of the given value.

["typeof", value]: string

Feature data

geometry-type

Gets the feature's geometry type: Point, MultiPoint, LineString, MultiLineString, Polygon, MultiPolygon.

["geometry-type"]: string

id

Gets the feature's id, if it has one.

["id"]: value

properties

Gets the feature properties object. Note that in some cases, it may be more efficient to use ["get", "property-name"] directly.

["properties"]: object

Lookup

at

Retrieves an item from an array.

["at", number, array]: ItemType

get

Retrieves a property value from the current feature's properties, or from another object if a second argument is provided. Returns null if the requested property is missing.

["get", string]: value

["get", string, object]: value

has

Tests for the presence of an property value in the current feature's properties, or from another object if a second argument is provided.

["has", string]: boolean

["has", string, object]: boolean

length

Gets the length of an array or string.

["length", string | array | value]: number

Decision

The expressions in this section can be used to add conditional logic to your styles. For example, the 'case' expression provides basic "if/then/else" logic, and 'match' allows you to map specific values of an input expression to different output expressions.

!

Logical negation. Returnstrueif the input is false, andfalseif the input is true.

["!", boolean]: boolean

!=

Returnstrueif the input values are not equal,falseotherwise. Equality is strictly typed: values of different types are always considered not equal. Accepts an optional collator argument to control locale-dependent string comparisons.

["!=", string, string]: boolean

["!=", string, string, collator]: boolean

["!=", number, number]: boolean

["!=", boolean, boolean]: boolean

["!=", null, null]: boolean

["!=", string, value]: boolean

["!=", string, value, collator]: boolean

["!=", number, value]: boolean

["!=", boolean, value]: boolean

["!=", null, value]: boolean

["!=", value, string]: boolean

["!=", value, string, collator]: boolean

["!=", value, number]: boolean

["!=", value, boolean]: boolean

["!=", value, null]: boolean

<

Returnstrueif the first input is strictly less than the second,falseotherwise. The inputs must be numbers or strings, and both of the same type. Accepts an optional collator argument to control locale-dependent string comparisons.

["<", number, number]: boolean

["<", string, string]: boolean

["<", string, string, collator]: boolean

<=

Returnstrueif the first input is less than or equal to the second,falseotherwise. The inputs must be numbers or strings, and both of the same type. Accepts an optional collator argument to control locale-dependent string comparisons.

["<=", number, number]: boolean

["<=", string, string]: boolean

["<=", string, string, collator]: boolean

==

Returnstrueif the input values are equal,falseotherwise. Equality is strictly typed: values of different types are always considered not equal. Accepts an optional collator argument to control locale-dependent string comparisons.

["==", string, string]: boolean

["==", string, string, collator]: boolean

["==", number, number]: boolean

["==", boolean, boolean]: boolean

["==", null, null]: boolean

["==", string, value]: boolean

["==", string, value, collator]: boolean

["==", number, value]: boolean

["==", boolean, value]: boolean

["==", null, value]: boolean

["==", value, string]: boolean

["==", value, string, collator]: boolean

["==", value, number]: boolean

["==", value, boolean]: boolean

["==", value, null]: boolean

>

Returnstrueif the first input is strictly greater than the second,falseotherwise. The inputs must be numbers or strings, and both of the same type. Accepts an optional collator argument to control locale-dependent string comparisons.

[">", number, number]: boolean

[">", string, string]: boolean

[">", string, string, collator]: boolean

>=

Returnstrueif the first input is greater than or equal to the second,falseotherwise. The inputs must be numbers or strings, and both of the same type. Accepts an optional collator argument to control locale-dependent string comparisons.

[">=", number, number]: boolean

[">=", string, string]: boolean

[">=", string, string, collator]: boolean

all

Returnstrueif all the inputs are true,falseotherwise. The inputs are evaluated in order, and evaluation is short-circuiting: once an input expression evaluates to false, the result isfalseand no further input expressions are evaluated.

["all", boolean, boolean]: boolean

["all", boolean, boolean, ...]: boolean

any

Returnstrueif any of the inputs are true,falseotherwise. The inputs are evaluated in order, and evaluation is short-circuiting: once an input expression evaluates to true, the result istrueand no further input expressions are evaluated.

["any", boolean, boolean]: boolean

["any", boolean, boolean, ...]: boolean

case

Selects the first output whose corresponding test condition evaluates to true.

["case",
    condition: boolean, output: OutputType, condition: boolean, output: OutputType, ...,
    default: OutputType
]: OutputType

coalesce

Evaluates each expression in turn until the first non-null value is obtained, and returns that value.

["coalesce", OutputType, OutputType, ...]: OutputType

match

Selects the output whose label value matches the input value, or the fallback value if no match is found. The input can be any string or number expression (e.g. ["get", "building_type"]). Each label can either be a single literal value or an array of values.

["match",
    input: InputType (number or string),
    label_1: InputType | [InputType, InputType, ...], output_1: OutputType,
    label_n: InputType | [InputType, InputType, ...], output_n: OutputType, ...,
    default: OutputType
]: OutputType

Ramps, scales, curves

interpolate

Produces continuous, smooth results by interpolating between pairs of input and output values ("stops"). The input may be any numeric expression (e.g., ["get", "population"]). Stop inputs must be numeric literals in strictly ascending order. The output type must be number, array <number>, or color.

Interpolate types:

["linear"]:interpolates linearly between the pair of stops just less than and just greater than the input.
["exponential", base]: Interpolates exponentially between the stops just less than and just greater than the input. base controls the rate at which the output increases: higher values make the output increase more towards the high end of the range. With values close to 1 the output increases linearly.
["cubic-bezier", x1, y1, x2, y2]: Interpolates using the cubic bezier curve defined by the given control points.

["interpolate",
    interpolation: ["linear"] | ["exponential", base] | ["cubic-bezier", x1, y1, x2, y2 ],
    input: number,
    stop_input_1: number, stop_output_1: OutputType,
    stop_input_n: number, stop_output_n: OutputType, ...
]: OutputType (number, array<number>, or Color)

step

Produces discrete, stepped results by evaluating a piecewise-constant function defined by pairs of input and output values ("stops"). The input may be any numeric expression (e.g., ["get", "population"]). Stop inputs must be numeric literals in strictly ascending order. Returns the output value of the stop just less than the input, or the first input if the input is less than the first stop.

["step",
    input: number,
    stop_output_0: OutputType,
    stop_input_1: number, stop_output_1: OutputType,
    stop_input_n: number, stop_output_n: OutputType, ...
]: OutputType

Variable binding

let

Binds expressions to named variables, which can then be referenced in the result expression using ["var", "variable_name"].

["let",
    string (alphanumeric literal), any, string (alphanumeric literal), any, ...,
    OutputType
]: OutputType

var

References variable bound using "let".

["var", previously bound variable name]: the type of the bound expression

String

concat

Returns a string consisting of the concatenation of the inputs.

["concat", string, string, ...]: string

downcase

Returns the input string converted to lowercase. Follows the Unicode Default Case Conversion algorithm and the locale-insensitive case mappings in the Unicode Character Database.

["downcase", string]: string

resolved-locale

Returns the IETF language tag of the locale being used by the provided collator. This can be used to determine the default system locale, or to determine if a requested locale was successfully loaded.

["resolved-locale", collator]: string

upcase

Returns the input string converted to uppercase. Follows the Unicode Default Case Conversion algorithm and the locale-insensitive case mappings in the Unicode Character Database.

["upcase", string]: string

Color

rgb

Creates a color value from red, green, and blue components, which must range between 0 and 255, and an alpha component of 1. If any component is out of range, the expression is an error.

["rgb", number, number, number]: color

rgba

Creates a color value from red, green, blue components, which must range between 0 and 255, and an alpha component which must range between 0 and 1. If any component is out of range, the expression is an error.

 ["rgba", number, number, number, number]: color

to-rgba

Returns a four-element array containing the input color's red, green, blue, and alpha components, in that order.

["to-rgba", color]: array<number, 4>

Math

-

For two inputs, returns the result of subtracting the second input from the first. For a single input, returns the result of subtracting it from 0.

["-", number, number]: number

["-", number]: number

*

Returns the product of the inputs.

 ["*", number, number, ...]: number

/

Returns the result of floating point division of the first input by the second.

["/", number, number]: number

%

Returns the remainder after integer division of the first input by the second.

["%", number, number]: number

^

Returns the result of raising the first input to the power specified by the second.

["^", number, number]: number

+

Returns the sum of the inputs.

["+", number, number, ...]: number

abs

Returns the absolute value of the input.

["abs", number]: number

acos

Returns the arccosine of the input.

["acos", number]: number

asin

Returns the arcsine of the input.

["asin", number]: number

atan

Returns the arctangent of the input.

["atan", number]: number

ceil

Returns the smallest integer that is greater than or equal to the input.

["ceil", number]: number

cos

Returns the cosine of the input.

["cos", number]: number

e

Returns the mathematical constant e.

["e"]: number

floor

Returns the largest integer that is less than or equal to the input.

["floor", number]: number

ln

Returns the natural logarithm of the input.

["ln", number]: number

ln2

Returns mathematical constant ln(2).

["ln2"]: number

log10

Returns the base-ten logarithm of the input.

["log10", number]: number

log2

Returns the base-two logarithm of the input.

["log2", number]: number

max

Returns the maximum value of the inputs.

["max", number, number, ...]: number

min

Returns the minimum value of the inputs.

["min", number, number, ...]: number

pi

Returns the mathematical constant pi.

["pi"]: number

round

Rounds the input to the nearest integer. Halfway values are rounded away from zero. For example, ["round", -1.5] evaluates to -2.

["round", number]: number

sin

Returns the sine of the input.

["sin", number]: number

sqrt

Returns the square root of the input.

["sqrt", number]: number

tan

Returns the tangent of the input.

["tan", number]: number

Heatmap

heatmap-density

Gets the kernel density estimation of a pixel in a heatmap layer, which is a relative measure of how many data points are crowded around a particular pixel. Can only be used in the heatmap-color property.

["heatmap-density"]: number

line-progress

Gets the progress along a gradient line. Can only be used in the line-gradient property.

["line-progress"]: number

Function

The value for any layout or paint property may be specified as a function. Functions allow you to make the appearance of a map feature change with the current zoom level and/or the feature's properties.

stops

Required (except for identity functions) array.

Functions are defined in terms of input and output values. A set of one input value and one output value is known as a "stop." Stop output values must be literal values (i.e. not functions or expressions), and appropriate for the property. For example, stop output values for a function used in the fill-color property must be colors.

property

Optional string.

If specified, the function will take the specified feature property as an input. See Zoom Functions and Property Functions for more information.

base

Optional number. Default is 1.

The exponential base of the interpolation curve. It controls the rate at which the function output increases. Higher values make the output increase more towards the high end of the range. With values close to 1 the output increases linearly.

type

Optional string. One of "identity", "exponential", "interval", or "categorical".

"identity" A function that returns its input as the output.
"exponential" A function that generates an output by interpolating between stops just less than and just greater than the function input. The domain (input value) must be numeric, and the style property must support interpolation. Style properties that support interpolation are marked marked with , the "exponential" symbol, and exponential is the default function type for these properties.
"interval" A function that returns the output value of the stop just less than the function input. The domain (input value) must be numeric. Any style property may use interval functions. For properties marked with, the "interval" symbol, this is the default function type.
"categorical" A function that returns the output value of the stop equal to the function input.

default

A value to serve as a fallback function result when a value isn't otherwise available. It is used in the following circumstances:

In categorical functions, when the feature value does not match any of the stop domain values.
In property and zoom-and-property functions, when a feature does not contain a value for the specified property.
In identity functions, when the feature value is not valid for the style property (for example, if the function is being used for a circle-color property but the feature property value is not a string or not a valid color).
In interval or exponential property and zoom-and-property functions, when the feature value is not numeric.

If no default is provided, the style property's default is used in these circumstances.

colorSpace

Optional string. One of "rgb", "lab", "hcl".

The color space in which colors interpolated. Interpolating colors in perceptual color spaces like LAB and HCL tend to produce color ramps that look more consistent and produce colors that can be differentiated more easily than those interpolated in RGB space.

"rgb" A function that returns its input as the output.
"exponential" Use the RGB color space to interpolate color values.
"lab" Use the LAB color space to interpolate color values.
"hcl" Use the HCL color space to interpolate color values, interpolating the Hue, Chroma, and Luminance channels individually.

Zoom functions allow the appearance of a map feature to change with map’s zoom level. Zoom functions can be used to create the illusion of depth and control data density. Each stop is an array with two elements: the first is a zoom level and the second is a function output value.

{
    "circle-radius": {
        "stops": [
            // zoom is 5 -> circle radius will be 1px
            [5, 1],
            // zoom is 10 -> circle radius will be 2px
            [10, 2]
        ]
    }
}

The rendered values of color, number, and array properties are interpolated between stops. Boolean and string property values cannot be interpolated, so their rendered values only change at the specified stops.

There is an important difference between the way that zoom functions render for layout and paint properties. Paint properties are continuously re-evaluated whenever the zoom level changes, even fractionally. The rendered value of a paint property will change, for example, as the map moves between zoom levels 4.1 and 4.6. Layout properties, on the other hand, are evaluated only once for each integer zoom level. To continue the prior example: the rendering of a layout property will not change between zoom levels 4.1 and 4.6, no matter what stops are specified; but at zoom level 5, the function will be re-evaluated according to the function, and the property's rendered value will change. (You can include fractional zoom levels in a layout property zoom function, and it will affect the generated values; but, still, the rendering will only change at integer zoom levels.)

Property functions allow the appearance of a map feature to change with its properties. Property functions can be used to visually differentate types of features within the same layer or create data visualizations. Each stop is an array with two elements, the first is a property input value and the second is a function output value. Note that support for property functions is not available across all properties and platforms at this time.

{
    "circle-color": {
        "property": "temperature",
        "stops": [
            // "temperature" is 0   -> circle color will be blue
            [0, 'blue'],
            // "temperature" is 100 -> circle color will be red
            [100, 'red']
        ]
    }
}

Zoom-and-property functions allow the appearance of a map feature to change with both its properties and zoom. Each stop is an array with two elements, the first is an object with a property input value and a zoom, and the second is a function output value. Note that support for property functions is not yet complete.

{
    "circle-radius": {
        "property": "rating",
        "stops": [
            // zoom is 0 and "rating" is 0 -> circle radius will be 0px
            [{zoom: 0, value: 0}, 0],

            // zoom is 0 and "rating" is 5 -> circle radius will be 5px
            [{zoom: 0, value: 5}, 5],

            // zoom is 20 and "rating" is 0 -> circle radius will be 0px
            [{zoom: 20, value: 0}, 0],

            // zoom is 20 and "rating" is 5 -> circle radius will be 20px
            [{zoom: 20, value: 5}, 20]
        ]
    }
}

Filter (depricated syntax)

In previous versions of the style specification, filters were defined using the deprecated syntax documented below. Though filters defined with this syntax will continue to work, we recommend using the more flexible expression syntax instead. Expression syntax and the deprecated syntax below cannot be mixed in a single filter definition.

Existential Filters

["has", key] feature[key] exists
["!has", key] feature[key] does not exist

Comparison Filters

["==", key, value] equality: feature[key] = value
["!=", key, value] inequality: feature[key] ≠ value
[">", key, value] greater than: feature[key] > value
[">=", key, value] greater than or equal: feature[key] ≥ value
["<", key, value] less than: feature[key] < value
["<=", key, value] less than or equal: feature[key] ≤ value

Set Membership Filters

["in", key, v0, ..., vn] set inclusion: feature[key] ∈ {v0, ..., vn}
["!in", key, v0, ..., vn] set exclusion: feature[key] ∉ {v0, ..., vn}

Combining Filters

["all", f0, ..., fn] logical AND: f0 ∧ ... ∧ fn
["any", f0, ..., fn] logical OR: f0 ∨ ... ∨ fn
["none", f0, ..., fn] logical NOR: ¬f0 ∧ ... ∧ ¬fn

A key must be a string that identifies a feature property, or one of the following special keys:

"$type": the feature type. This key may be used with the "==","!=", "in", and "!in" operators. Possible values are"Point", "LineString", and "Polygon".
"$id": the feature identifier. This key may be used with the "==","!=", "has", "!has", "in", and "!in" operators.

A value (and v0, ..., vn for set operators) must be a string, number, or boolean to compare the property value against.

Set membership filters are a compact and efficient way to test whether a field matches any of multiple values.

The comparison and set membership filters implement strictly-typed comparisons; for example, all of the following evaluate to false: 0 < "1", 2 == "2", "true" in [true, false].

The "all", "any", and "none" filter operators are used to create compound filters. The values f0, ..., fn must be filter expressions themselves.

["==", "$type", "LineString"]

This filter requires that the class property of each feature is equal to either "street-major", "street_minor", or "street_limited".

["in", "class", "street_major", "street_minor", "street_limited"]

The combining filter "all" takes the three other filters that follow it and requires all of them to betruefor a feature to be included: a feature must have a class equal to "street_limited", its admin_level must be greater than or equal to 3, and its type cannot be Polygon. You could change the combining filter to "any" to allow features matching any of those criteria to be included - features that are Polygons, but have a different class value, and so on.

[
    "all",
    ["==", "class", "street_limited"],
    [">=", "admin_level", 3],
    ["!in", "$type", "Polygon"]
]