geojson

go-whosonfirst-geojson-v2

Go tools for working with Who's On First documents

Install

You will need to have both Go (specifically version 1.12 or higher because we're using Go modules) and the make programs installed on your computer. Assuming you do just type:

make tools

All of this package's dependencies are bundled with the code in the vendor directory.

Notice

This package is stuck in that awkward in-between place where it is basically deprecated but still being included as a dependency to a lot of other packages.

Which is to say: While this package is not officially deprecated yet it is on its way to being deprecated. Bug fixes will be applied when necessary but otherwise all work is being applied to the whosonfirst/go-whosonfirst-feature package.

Basically this package tries to do too many things, specifically around defining GeoJSON-related structs and interfaces. It's not really worth the effort and better to use paulmach/orb/geojson for geometry and GeoJSON-related operations and [tidwall/gjson](https://github.com/tidwall/gjson] for query-related operations using plain-vanilla []byte elements. This is the approach taken by the go-whosonfirst-feature package.

If you are using this package in your code it would be best to migrate it to use equivalent functionality defined in the go-whosonfirst-feature package.

History

The goal of this package was to replace the existing go-whosonfirst-geojson package.

geojson-v2?

Yeah, I don't really like it either but this package is basically 100% backwards incompatible with github.com/whosonfirst/go-whosonfirst-geojson and while I don't really think anyone else is using it I don't like the idea of suddenly breaking everyone's code.

Interfaces

Unlike the first go-whosonfirst-geojson package this one at least attempts to define a simplified interface for working with GeoJSON features. These are still in flux.

Please finish writing me.

geojson.Feature

type Feature interface {
	Type() string
	Id() int64
	Name() string
	Placetype() string
	ToString() string
	ToBytes() []byte
	BoundingBoxes() (BoundingBoxes, error)
	Polygons() ([]Polygon, error)
	ContainsCoord(geom.Coord) (bool, error)
}

geojson.BoundingBoxes

type BoundingBoxes interface {
	Bounds() []*geom.Rect
	MBR() geom.Rect
}

geojson.Centroid

type Centroid interface {
	Coord() geom.Coord
	Source() string
}

geojson.Polygon

type Polygon interface {
	ExteriorRing() geom.Polygon
	InteriorRings() []geom.Polygon
	ContainsCoord(geom.Coord) bool
}

Usage

Simple

import (
	"github.com/whosonfirst/go-whosonfirst-geojson-v2/whosonfirst"
	"log"
)

func main() {

	path := "/usr/local/data/whosonfirst-data/data/101/736/545/101736545.geojson"
	f, err := whosonfirst.LoadFeatureFromFile(path)

	if err != nil {
		log.Fatal(err)
	}

	// prints "Montreal"
	log.Println("Name is ", f.Name())
}

See also

• github.com/skelterjohn/geom
• https://github.com/whosonfirst/go-whosonfirst-geojson