Feature

On this page

Shape
Example
Good to know
In JSON
Details

A shape with your own data attached, in GeoJSON's form, as a map library takes one.

Use it to send one shape and its properties to a map. To send a whole layer, use FeatureCollection. Inside your app, store your own records with a Point or Polygon field.

Shape

Field	Type	Required?
`geometry`	`G`	Yes
`properties`	`P`	Yes

Example

example

type StopInfo = Object {    name: Text}var stop: Feature<Point, StopInfo> = Feature {    geometry: Point { latitude: 51.5072 longitude: -0.1276 altitude: none }    properties: StopInfo { name: "Charing Cross" }}assert stop.properties.name == "Charing Cross"

Good to know

Name both types when you use it, the geometry and the properties: Feature<Point, StopInfo>. The geometry can be one of the six shapes or Geometry.
It has no id, so an incoming feature with one is refused.
== tells you whether two are the same. < and list.sort_by don't take it, so sort by one of its parts instead.

In JSON

A GeoJSON object of its geometry and properties, in a request, a response or json.write:

json

{"type":"Feature","geometry":{"type":"Point","coordinates":[-0.1276,51.5072]},"properties":{"name":"Site A"}}

Details

Text form, storage, how it is shown, and operations

Feature is in the group Geospatial, and has been in Jadpo since 0.1.0.

Text form

It has no single text form, so text.from and text.parse don't take it.

How it is stored

It is stored in one column named for the field, of type jsonb. {"type":"Feature","geometry":{"type":"Point","coordinates":[-0.1276,51.5072]},"properties":{"name":"Site A"}} is stored as '{"type":"Feature","geometry":{"type":"Point","coordinates":[-0.1276,51.5072]},"properties":{"name":"Site A"}}'::jsonb.

How it is shown to people

text.format(value, locale:) shows it to people in their locale.

With locale: Locale.en_gb:

Value	Shown
`{"type":"Feature","geometry":{"type":"Point","coordinates":[-0.1276,51.5072]},"properties":{"name":"Site A"}}`	`""`

Operations

It also takes text.format, json.read, json.write and ==. How every standard type behaves says how they work.

Markdown for agents: /docs/types/type-feature.md.Built from Jadpo main at aee2e8f.