@mobilabs/shp

SHP

SHP is a light Javascript API for reading Natural Earth's DB files. SHP provides methods to extract data from the database and creates GeoJSON outputs.

SHP runs on both Node.js and broswsers that are ECMAScript 2015 (ES6) compliant.

Usage

Usage

Extract data and create a GeoJSON object:

const SHP = require('@mobilabs/shp');

// Create an object:
const shp = SHP();

// Load the Natural Earth database:
await shp.load('<path>/ne_110m_admin_0_countries')

// Get a GeoJSON collection:
const collection = shp.getCollection();

// Get a GeoJSON feature:
const feature = shp.getFeature('feature number');

The GeoJSON object looks like:

{
  bbox: [ ... ],
  type: 'FeatureCollection',
  features: [
    { type: 'Feature', properties: [Object], geometry: [Object] },
    ...
    { type: 'Feature', properties: [Object], geometry: [Object] }
  ]
}

A Feature looks like:

{
  type: 'Feature',
  properties: { ... },
  geometry : {
    type: 'Polygon'
    coordinates: [ ... ]
  }
}

Nota:

A Natural Earth's database is a folder that contains, at least, three files having the same name as the folder and with the suffix .dbf, .shp and .VERSION.txt. For instance, Natural Earth's database ne_50m_admin_0_countries must contains the files: ne_50m_admin_0_countries.dbf, ne_50m_admin_0_countries.shp and ne_50m_admin_0_countries.VERSION.txt.

API

This module implements three methods:

• whoami()
• load(database path)
• getFeature(feature number),
• getCollection(),
• getSource(),

whoami()

This method returns the library name and version.

load(path)

This method loads the Natural Earth' database.

This method requires one argument, the path to the database.

getFeature(n)

This method extracts one Feature from Natural Earth's database and returns a Javascript GeoJSON object.

This method requires one argument. Its is a number - the Feature number. It starts from 1.

getCollection()

This method extracts a FeatureCollection from Natural Earth's database and returns a Javascript GeoJSON object. A FeatureCollection is a set of Feature.

getSource()

This method returns an object that contains the name and the version of the Natural Earth's database.

License

MIT.