layer:
  id: "poi"
  description: |
      [Points of interests](http://wiki.openstreetmap.org/wiki/Points_of_interest) containing
      a of a variety of OpenStreetMap tags. Mostly contains amenities, sport, shop and tourist POIs.
  buffer_size: 8
  srs: +proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over
  fields:
    name: The OSM [`name`](http://wiki.openstreetmap.org/wiki/Key:name) value of the POI.
    name_en: The english `name:en` value if available.
    class: |
        More general classes of POIs. If there is no more general `class` for the `subclass`
        this field will contain the same value as `subclass`.
        But for example for schools you only need to style the class `school` to filter the subclasses `school`
        and `kindergarten`. Or use the class `shop` to style all shops.
    subclass: |
        Original value of either the
        [`amenity`](http://wiki.openstreetmap.org/wiki/Key:amenity),
        [`leisure`](http://wiki.openstreetmap.org/wiki/Key:leisure),
        [`landuse`](http://wiki.openstreetmap.org/wiki/Key:landuse),
        [`sport`](http://wiki.openstreetmap.org/wiki/Key:sport),
        [`tourism`](http://wiki.openstreetmap.org/wiki/Key:tourism)
        or [`shop`](http://wiki.openstreetmap.org/wiki/Key:shop)
        tag.  Use this to do more precise styling.
    gridrank: |
        The POIs are ranked ascending according to their importance within a grid. The `gridrank` value shows the
        local relative importance of a POI within it's cell in the grid. This can be used to reduce label density at z14.
        Since all POIs already need to be contained at `z14` you can use `less than gridrank=10` epxression to limit
        POIs. At some point like z17 you can show all POIs.
  datasource:
    geometry_field: geometry
    srid: 900913
    query: (SELECT geometry, name, name_en, class, subclass, gridrank FROM layer_poi(!bbox!, z(!scale_denominator!), !pixel_width!)) AS t
schema:
  - ./class.sql
  - ./layer.sql
datasources:
  - type: imposm3
    mapping_file: ./mapping.yaml