geojson

What is geojson?

The geojson npm package provides utilities for working with GeoJSON data, which is a format for encoding a variety of geographic data structures. It allows you to create, manipulate, and validate GeoJSON objects easily.

What are geojson's main functionalities?

Creating GeoJSON Objects

This feature allows you to create GeoJSON objects from an array of data points. The example demonstrates how to convert an array of locations with latitude and longitude into a GeoJSON object.

const geojson = require('geojson');
const data = [
  { name: 'Location 1', lat: 40.7128, lng: -74.0060 },
  { name: 'Location 2', lat: 34.0522, lng: -118.2437 }
];
const geojsonData = geojson.parse(data, { Point: ['lat', 'lng'] });
console.log(JSON.stringify(geojsonData, null, 2));

Validating GeoJSON Objects

This feature allows you to validate GeoJSON objects to ensure they conform to the GeoJSON specification. The example shows how to validate a GeoJSON object representing a point feature.

const geojson = require('geojson');
const geojsonData = {
  type: 'FeatureCollection',
  features: [
    {
      type: 'Feature',
      geometry: {
        type: 'Point',
        coordinates: [-74.0060, 40.7128]
      },
      properties: {
        name: 'Location 1'
      }
    }
  ]
};
const isValid = geojson.isValid(geojsonData);
console.log(isValid);

Converting GeoJSON to Other Formats

This feature allows you to convert GeoJSON objects to other formats such as KML. The example demonstrates how to convert a GeoJSON object to KML format.

const geojson = require('geojson');
const geojsonData = {
  type: 'FeatureCollection',
  features: [
    {
      type: 'Feature',
      geometry: {
        type: 'Point',
        coordinates: [-74.0060, 40.7128]
      },
      properties: {
        name: 'Location 1'
      }
    }
  ]
};
const kml = geojson.toKML(geojsonData);
console.log(kml);

Other packages similar to geojson

terraformer

Terraformer is a JavaScript library for working with GeoJSON, including parsing, converting, and manipulating GeoJSON data. It offers more advanced spatial operations compared to geojson, such as buffering and union operations.

geojson-utils

GeoJSON Utils is a utility library for working with GeoJSON data. It provides functions for calculating distances, bounding boxes, and other spatial operations. It is more focused on spatial calculations compared to geojson.

turf

Turf is a powerful geospatial analysis library for JavaScript. It provides a wide range of spatial operations, including measurements, transformations, and data classification. Turf is more comprehensive and feature-rich compared to geojson.

README

node-geojson

Convert an array of objects with coordinates/geometry to a GeoJSON feature collection. Only works with point data at the moment.

Installation

npm install geojson

Getting Started

var GeoJSON = require('geojson');

Example Usage

Sample Data

var data = [
  {
    name: 'Location A',
    category: 'Store',
    lat: 39.984,
    lng: -75.343
  },
  {
    name: 'Location B',
    category: 'House',
    lat: 39.284,
    lng: -75.833
  },
  {
    name: 'Location C',
    category: 'Office',
    lat: 39.123,
    lng: -74.534
  }
];

Specify only coordinate parameters

GeoJSON.parse(data, { point: ['lng', 'lat'] });

  { "type": "FeatureCollection",
    "features": [
      { "type": "Feature",
        "geometry": {"type": "Point", "coordinates": [-75.343, 39.984]},
        "properties": { 
          "name": "Location A",
          "category": "Store"
        }
      },
      { "type": "Feature",
        "geometry": {"type": "Point", "coordinates": [-75.833, 39.284]},
        "properties": { 
          "name": "Location B",
          "category": "House"
        }
      },
      { "type": "Feature",
        "geometry": {"type": "Point", "coordinates": [ -75.534, 39.123]},
        "properties": { 
          "name": "Location C",
          "category": "Office"
        }
      }
    ]
  }

Specify coordinate parameters and include

GeoJSON.parse(data, { point: ['lng', 'lat'], include: ['name']});

  { "type": "FeatureCollection",
    "features": [
      { "type": "Feature",
        "geometry": {"type": "Point", "coordinates": [-75.343, 39.984]},
        "properties": { 
          "name": "Location A"
        }
      },
      ...
      { "type": "Feature",
        "geometry": {"type": "Point", "coordinates": [ -75.534, 39.123]},
        "properties": { 
          "name": "Location C"
        }
      }
    ]
  }

Parameters

• point - array of field names that contain x and y coordinates. Example: point: [lat, lng]
• include - List of fields to include as properties. All other fields will be ignored
• exclude - List of fields to that shouldn't be included in properties. All other fields will be added (besides geometry fields)