diff --git a/3.0.0/README.md b/3.0.0/README.md index c0f91d0..7c51d4a 100644 --- a/3.0.0/README.md +++ b/3.0.0/README.md @@ -227,6 +227,73 @@ An array of tile endpoints. {z}, {x} and {y}, if present, are replaced with the ``` ## 3.15 `vector_layers` + +REQUIRED. + +A JSON object whose value is an array of JSON objects. Each of those JSON objects describes one layer of vector tile data. A `vector_layer` object MUST contain the `id` and `fields` keys, and MAY contain the `description`, `minzoom`, or `maxzoom` keys. + +#### 3.15.1 `id` + +REQUIRED. + +A string value representing the the layer id. For added context, this is referred to as the `name` of the layer in the [Mapbox Vector Tile spec](https://github.com/mapbox/vector-tile-spec/tree/master/2.1#41-layers). + +#### 3.15.2 `fields` + +REQUIRED. + +A JSON object whose keys and values are the names and descriptions of attributes available in this layer. Each value (description) MUST be a string that describes the underlying data. If no fields are present the `fields` key MUST be an empty object. + +#### 3.15.3 `description` + +OPTIONAL. + +A string representing a human-readable description of the entire layer's contents. + +#### 3.15.4 `minzoom` and `maxzoom` + +OPTIONAL. + +A number representing the lowest/highest zoom level whose tiles this layer appears in. `minzoom` MUST be greater than or equal to the tileset's `minzoom`. `maxzoom` MUST be less than or equal to the tileset's `maxzoom`. + +These keys are used to describe the situation where different sets of vector layers appear in different zoom levels of the same tileset, for example in a case where a "minor roads" layer is only present at high zoom levels. + +```JSON +{ + "vector_layers": [ + { + "id": "roads", + "description": "Roads and their attributes", + "minzoom": 2, + "maxzoom": 16, + "fields": { + "type": "One of: trunk, primary, secondary", + "lanes": "Number", + "name": "String", + "sidewalks": "Boolean" + } + }, + { + "id": "countries", + "description": "Admin 0 (country) boundaries", + "minzoom": 0, + "maxzoom": 16, + "fields": { + "iso": "ISO 3166-1 Alpha-2 code", + "name": "English name of the country", + "name_ar": "Arabic name of the country" + } + }, + { + "id": "buildings", + "description": "A layer with an empty fields object", + "fields": {} + } + ] +} +``` + + ## 3.16 `version` OPTIONAL. Default: "1.0.0".