geojson

go-whosonfirst-geojson

Go tools for working with Who's On First documents

Important

This package not been officially deprecated yet but it will be as soon as the go-whosonfirst-geojson-v2 package is complete. Until then only immediate bug fixes will be addressed. No additional features will be added to this package.

Install

You will need to have both Go (specifically a version of Go more recent than 1.6 so let's just assume you need Go 1.8 or higher) and the make programs installed on your computer. Assuming you do just type:

make bin

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

Usage

package main

import (
	"flag"
	"fmt"
	geojson "github.com/whosonfirst/go-whosonfirst-geojson/whosonfirst"
)

func main() {

	flag.Parse()
	args := flag.Args()

	for _, path := range args {

		// This is mostly just helper code to read the file
		// and call geojson.UnmarshalFeature (from a bag of bytes)

		f, parse_err := geojson.UnmarshalFile(path)

		if parse_err != nil {
			panic(parse_err)
		}

		fmt.Printf("# %s\n", path)
		fmt.Println(f.Dumps())
	}

}

The longer version

This isn't really a "GeoJSON" specific library, yet. Right now it's just a thin wrapper around the Gabs utility for wrangling unknown JSON structures in to a Go WOFFeature struct.

Eventually it would be nice to make Gabs hold hands with Paul Mach's go.geojson and use the former to handle the GeoJSON properties dictionary. But that day is not today.

The longer longer version

Right now this library has evolved and grown functionality on as-needed basis, targeting on Who's On First specific use-cases. As such it consists of a handful of WOF struct types - WOFFeature and WOFPolygon and WOFSpatial - that are wrappers around other people's heavy-lifting. There are not any WOF related interfaces but that's really the direction we want to head in... but we're not there yet. So things will probably change in the short-term. Not too much , hopefully.

Utilities

Things you can find in the cmd and ultimately the bin directories.

wof-geojson-contains

A tool for testing wether a given latitude and longitude is contained by one or more GeoJSON files. As of this writing this tool lacks command line parameters for defining latitide and longitude.

# ASSUMING
# lat := 45.523668
# lon := -73.600159

# PLAIN VANILLA POLYGON

$> ./bin/wof-geojson-contains /usr/local/mapzen/whosonfirst-data/data/404/529/181/404529181.geojson /usr/local/mapzen/whosonfirst-data/data/857/848/31/85784831.geojson
/usr/local/mapzen/whosonfirst-data/data/404/529/181/404529181.geojson has this many polygons: 1
/usr/local/mapzen/whosonfirst-data/data/404/529/181/404529181.geojson #1 has 3 interior rings
/usr/local/mapzen/whosonfirst-data/data/404/529/181/404529181.geojson #1 contains point false
/usr/local/mapzen/whosonfirst-data/data/404/529/181/404529181.geojson contains point: false
/usr/local/mapzen/whosonfirst-data/data/404/529/181/404529181.geojson f.Contains() point: false
---
/usr/local/mapzen/whosonfirst-data/data/857/848/31/85784831.geojson has this many polygons: 1
/usr/local/mapzen/whosonfirst-data/data/857/848/31/85784831.geojson #1 has 0 interior rings
/usr/local/mapzen/whosonfirst-data/data/857/848/31/85784831.geojson #1 contains point true
/usr/local/mapzen/whosonfirst-data/data/857/848/31/85784831.geojson contains point: true
/usr/local/mapzen/whosonfirst-data/data/857/848/31/85784831.geojson f.Contains() point: true
---

# MULTI POLYGON

$> ./bin/wof-geojson-contains /usr/local/mapzen/whosonfirst-data/data/136/251/273/136251273.geojson
/usr/local/mapzen/whosonfirst-data/data/136/251/273/136251273.geojson has this many polygons: 8
/usr/local/mapzen/whosonfirst-data/data/136/251/273/136251273.geojson #1 has 0 interior rings
/usr/local/mapzen/whosonfirst-data/data/136/251/273/136251273.geojson #1 contains point false
/usr/local/mapzen/whosonfirst-data/data/136/251/273/136251273.geojson #2 has 0 interior rings
/usr/local/mapzen/whosonfirst-data/data/136/251/273/136251273.geojson #2 contains point false
/usr/local/mapzen/whosonfirst-data/data/136/251/273/136251273.geojson #3 has 0 interior rings
/usr/local/mapzen/whosonfirst-data/data/136/251/273/136251273.geojson #3 contains point false
/usr/local/mapzen/whosonfirst-data/data/136/251/273/136251273.geojson #4 has 0 interior rings
/usr/local/mapzen/whosonfirst-data/data/136/251/273/136251273.geojson #4 contains point true
/usr/local/mapzen/whosonfirst-data/data/136/251/273/136251273.geojson #5 has 0 interior rings
/usr/local/mapzen/whosonfirst-data/data/136/251/273/136251273.geojson #5 contains point false
/usr/local/mapzen/whosonfirst-data/data/136/251/273/136251273.geojson #6 has 0 interior rings
/usr/local/mapzen/whosonfirst-data/data/136/251/273/136251273.geojson #6 contains point false
/usr/local/mapzen/whosonfirst-data/data/136/251/273/136251273.geojson #7 has 0 interior rings
/usr/local/mapzen/whosonfirst-data/data/136/251/273/136251273.geojson #7 contains point false
/usr/local/mapzen/whosonfirst-data/data/136/251/273/136251273.geojson #8 has 0 interior rings
/usr/local/mapzen/whosonfirst-data/data/136/251/273/136251273.geojson #8 contains point false
/usr/local/mapzen/whosonfirst-data/data/136/251/273/136251273.geojson contains point: true
/usr/local/mapzen/whosonfirst-data/data/136/251/273/136251273.geojson f.Contains() point: true

wof-geojson-dump

Print the ID, name and placetype for one or more GeoJSON files. This is a utility to test the Id and Name and Placetype methods for a GeoJSON document parsed by go-whosonfirst-geojson

$> ./bin/wof-geojson-dump /usr/local/mapzen/whosonfirst-data/data/101/736/545/101736545.geojson
# /usr/local/mapzen/whosonfirst-data/data/101/736/545/101736545.geojson
ID is 101736545
Name is Montréal
Placetype is locality

wof-geojson-enspatialize

This is a utility for testing the SpatializeGeom functionality for one or more GeoJSON files.

./bin/wof-geojson-enspatialize /usr/local/mapzen/whosonfirst-data/data/101/736/545/101736545.geojson
Enspatialize bounding box
&{0xc210038d20 101736545 Montréal locality -1}
101736545
Enspatialize geom
1
&{0xc210038de0 101736545 Montréal locality 0}

wof-geojson-polygons

This is a utility for testing the GeomToPolygons functionality, by printing the number of points in each outer ring, for one or more GeoJSON files.

./bin/wof-geojson-polygons /usr/local/mapzen/whosonfirst-data/data/101/736/545/101736545.geojson
5206 points

wof-geojson-validate

Validate a directory full of GeoJSON files. Specifically validate that they are valid JSON and nothing else. A more full-feature Who's On First validator in Go may be written in the future but today is not that day. You could take a look at py-mapzen-whosonfirst-validator for that.

$> /bin/wof-geojson-validate -source /usr/local/mapzen/whosonfirst-data/data/ -processes 200
time to validate 401499 files: 1m11.002168559s

See also

• https://www.github.com/jeffail/gabs