artisanweblab/geojson

GeoJSON implementation for PHP

dev-master 2022-11-04 07:54 UTC

Requires

• php: ^8.0
• ext-json: *

Requires (Dev)

• phpunit/phpunit: ^9.5.4

MIT

• Oleksandr Shapoval

README

This library implements the GeoJSON format specification.

The GeoJson namespace includes classes for each data structure defined in the GeoJSON specification. Core GeoJSON objects include geometries, features, and collections. Geometries range from primitive points to more complex polygons. Classes also exist for bounding boxes and coordinate reference systems.

Installation

$ composer require "artisanweblab/geojson"

Usage

Classes in this library are immutable.

GeoJson Constructors

Geometry objects are constructed using a single coordinates array. This may be a tuple in the case of a Point, an array of tuples for a LineString, etc. Constructors for each class will validate the coordinates array and throw an InvalidArgumentException on error.

More primitive geometry objects may also be used for constructing complex objects. For instance, a LineString may be constructed from an array of Point objects.

Feature objects are constructed from a geometry object, associative properties array, and an identifier, all of which are optional.

Feature and geometry collection objects are constructed from an array of their respective types.

JSON Serialization

use ArtisanWebLab\GeoJson\Geometry\Point;
$point = Point::latLng([50.4019514, 30.3926095]);
$json = json_encode($point);

Printing the $json variable would yield (sans whitespace):

{
    "type": "Point",
    "coordinates": [30.3926095, 50.4019514]
}

JSON Unserialization

The core GeoJson class implements an internal JsonUnserializable interface, which defines a static factory method, jsonUnserialize(), that can be used to create objects from the return value of json_decode().

use ArtisanWebLab\GeoJson\GeoJson;
$json = '{ "type": "Point", "coordinates": [30.3926095, 50.4019514] }';
$point = GeoJson::jsonUnserialize($json);

If errors are encountered during unserialization, an UnserializationException will be thrown by jsonUnserialize(). Possible errors include:

• Missing properties (e.g. type is not present)
• Unexpected values (e.g. coordinates property is not an array)
• Unsupported type string when parsing a GeoJson object or CRS

Polyline Decoder

$origin = 'Маріїнський палац, 5A, вулиця Михайла Грушевського, Київ, 01008';
$destination = 'Києво-Печерська лавра, вулиця Лаврська, 15, Київ, 01015';

$request = Http::get('https://maps.googleapis.com/maps/api/directions/json', [
    'origin'      => $origin,
    'destination' => $destination,
    'language'    => 'ua',
    'key'         => '...',
]);
$response = $request->json();

$lineStrings = [];

foreach ($response['routes'] as $route) {
    $polylineFromGoogleMapsAPI = $route['overview_polyline']['points'];
    $lineStrings[] = GeoJson::decodePolyline($polylineFromGoogleMapsAPI);
}

{
    "type":"LineString",
    "coordinates":[
        [30.5385,50.4478],
        [30.53711,50.44677],
        //..
        [30.55699,50.43555],
        [30.55701,50.43553]
    ]
}