GIS and PostGIS#

Tina4 stores geographic points in PostGIS, measures distance in metres, and returns map-ready GeoJSON. Coordinates always use longitude first. GPS may supply coordinates, but GIS is the feature.

Define a point field#

Enable PostGIS with CREATE EXTENSION IF NOT EXISTS postgis;.

class ChargePoint < Tina4::ORM  point_field :locationend​site.location = Tina4::Point.new(18.4241, -33.9249)site.save

Tina4 creates geography(Point,4326) and an idempotent GiST index. Unsupported database engines and PostgreSQL without PostGIS fail clearly. Tina4::Point.parse accepts a Point, number pair, WKT or EWKT, GeoJSON Point or Feature, and WKB or EWKB. It rejects invalid ranges, non-finite numbers, non-point geometry, and conflicting SRIDs before SQL runs.

Query and return GeoJSON#

nearby = ChargePoint.query  .within_distance("location", [18.42, -33.92], 5_000)  .select_distance("location", [18.42, -33.92], alias_name: "metres")  .order_by_distance("location", [18.42, -33.92])  .get​feature = site.to_featurecollection = Tina4::ORM.feature_collection(nearby)

The query builder also provides intersects for bound WKT, EWKT, or GeoJSON geometry and bbox for a validated bounding box. Spatial values use bound parameters. Column and alias names are validated as identifiers.

to_feature moves the chosen Point into geometry and keeps other selected fields in properties. A null point creates "geometry": null. feature_collection preserves query order. Supply a geometry field for models with several Point fields and an include list to limit properties.

Version 3.13.104 persists Point fields only. It does not persist lines, polygons, rasters, tiles, geocoding results, or routes. intersects may accept a polygon as query geometry. PostGIS is the only storage provider.