GeoJSON

The built-in GeoJSON data provider opens GeoJSON files as shapes. Files are parsed in the browser, in a worker. The provider is named after GeoJSON rather than JSON: a JSON document without GeoJSON structure is not shapes, so there is no plain JSON provider.

Data source

GeoJSON data sources have the type "geojson" and accept the following fields:

Field	Type	Description
type	string	Always "geojson".
source	string	URL or path of the GeoJSON file (see Referencing data).
idProperty	string	Feature property holding the ID of each shape (see Feature IDs). Defaults to the position of the feature.
nameProperty	string	Feature property holding the name of each shape.
table	string	ID of the table annotating the shapes (see Data model).

Shapes

The file holds a FeatureCollection, a single Feature, a GeometryCollection or a bare geometry. Polygon and MultiPolygon geometries are read as shapes; a feature with another geometry, or without one, is skipped with a warning.

Feature IDs

The idProperty names the feature property holding the shape IDs, which keep their JSON types: integers stay integers and strings stay strings, so a table annotating the shapes has to key its rows the same way. Without an idProperty, shapes are keyed by their position in the file. A feature whose ID is missing, empty, or neither a string nor an integer fails the load.

Limitations

• idProperty and nameProperty can only be set for a FeatureCollection. Setting one for another root fails the load.
• Only polygons and multi-polygons are read. Points and lines are skipped.

API

The data provider is implemented in the @tissuumaps/storage package as GeoJSONShapesDataProvider. The file is parsed in a worker.