Other

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) :ref:`types-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.”

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 Enum. One of identity, exponential, interval, categorical.

identity

functions return their input as their output.

exponential

functions generate an output by interpolating between stops just less than and just greater than the function input. The domain must be numeric. This is the default for properties marked with , the “exponential” symbol.

interval

functions return the output value of the stop just less than the function input. The domain must be numeric. This is the default for properties marked with , the “interval” symbol.

categorical

functions return 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 Enum. 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

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.

Support	Mapbox	GeoTools	OpenLayers
basic functionality	>= 0.10.0	>= 17.1	>= 2.4.0
property	>= 0.18.0	>= 17.1	>= 2.4.0
type	>= 0.18.0	>= 17.1	>= 2.4.0
exponential type	>= 0.18.0	>= 17.1	>= 2.4.0
interval type	>= 0.18.0	>= 17.1	>= 2.4.0
categorical type	>= 0.18.0	>= 17.1	>= 2.4.0
identity type	>= 0.18.0	>= 17.1	>= 2.4.0
default type	>= 0.18.0	>= 17.1	>= 2.4.0
colorSpace type	>= 0.26.0	Not yet supported	>= 2.4.0

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. Enum, 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 differentiate 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

A filter selects specific features from a layer. A filter is an array of one of the following forms:

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] ∈ {v_0, …, v_n}

["!in", key, v0, ..., vn] set exclusion: feature[key] ∉ {v_0, …, v_n}

Combining Filters

["all", f0, ..., fn] logical AND: f_0 ∧ … ∧ f_n

["any", f0, ..., fn] logical OR: f_0 ∨ … ∨ f_n

["none", f0, ..., fn] logical NOR: ¬f_0 ∧ … ∧ ¬f_n

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 v_0, …, v_n 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 f_0, …, f_n 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 be true for 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"]
]

Support	Mapbox	GeoTools	OpenLayers
basic functionality	>= 0.10.0	>= 17.1	>= 2.4.0
has/!has	>= 0.19.0	>= 17.1	>= 2.4.0

Note

This Mapbox Style Specification document was started from the BSD github.com/mapbox/mapbox-gl-js repository.

The specification is reproduced here with details on the GeoTools MBStyle implementation. Where appropriate examples have been changed to reference GeoWebCache.

Documentation BSD license:

Copyright (c) 2016, Mapbox

All rights reserved.

Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice,
      this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright notice,
      this list of conditions and the following disclaimer in the documentation
      and/or other materials provided with the distribution.
    * Neither the name of Mapbox GL JS nor the names of its contributors
      may be used to endorse or promote products derived from this software
      without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.