Before we dive in to the tutorial ...
This is a tutorial for using the OpenCage Geocoding API in Node.js. You will need to sign up for an OpenCage API key. Once you've done that we recommend you spend five minutes- playing with the demo page, so that you see the actual response the API returns.
- browsing the API documentation, so you understand the optional parameters, best practices, possible response codes, and the rate limiting on free trial accounts.
Nodejs packages for accessing the OpenCage Geocoding API
In node.js there are two packages you can use:
Install nodejs package
$ npm install opencage-api-client
# or using yarn
$ yarn add opencage-api-client
Set API key
Create a.env file with:
OCD_API_KEY=YOUR-API-KEYReverse geocode (coordinates to place)
const opencage = require('opencage-api-client');
opencage.geocode({q: '37.4396, -122.1864', language: 'fr'}).then(data => {
// console.log(JSON.stringify(data));
if (data.status.code == 200) {
if (data.results.length > 0) {
var place = data.results[0];
console.log(place.formatted);
console.log(place.components.road);
console.log(place.annotations.timezone.name);
}
} else if (data.status.code == 402) {
console.log('hit free-trial daily limit');
console.log('become a customer: https://opencagedata.com/pricing');
} else {
// other possible response codes:
// https://opencagedata.com/api#codes
console.log('error', data.status.message);
}
}).catch(error => {
console.log('error', error.message);
});
// ... prints
// 1330 Middle Avenue, Menlo Park, Californie 94025, États-Unis d'Amérique
// Middle Avenue
// America/Los_Angeles
Forward geocode (address to coordinates)
const opencage = require('opencage-api-client');
opencage.geocode({q: 'Theresienhöhe 11, München'}).then(data => {
console.log(JSON.stringify(data));
if (data.status.code == 200) {
if (data.results.length > 0) {
var place = data.results[0];
console.log(place.formatted);
console.log(place.geometry);
console.log(place.annotations.timezone.name);
}
} else if (data.status.code == 402) {
console.log('hit free-trial daily limit');
console.log('become a customer: https://opencagedata.com/pricing');
} else {
// other possible response codes:
// https://opencagedata.com/api#codes
console.log('error', data.status.message);
}
}).catch(error => {
console.log('error', error.message);
});
// ... prints
// Theresienhöhe 11, 80339 Munich, Germany
// { lat: 48.1341651, lng: 11.5464794 }
// Europe/Berlin
Install nodejs package
# install with npm or yarn
$ npm install node-geocoder
Forward geocode (address to coordinates)
var NodeGeocoder = require('node-geocoder');
var geocoder = NodeGeocoder({
provider: 'opencage',
apiKey: 'YOUR-API-KEY'
});
// Using callback
geocoder.geocode('37.4396, -122.1864', function(err, res) {
console.log(res);
});
geocoder.geocode('29 champs elysée paris', function(err, res) {
console.log(res);
});
// Or using Promise
geocoder.geocode('37.4396, -122.1864')
.then(function(res) {
console.log(res);
})
.catch(function(err) {
console.log(err);
});
Batch geocode addresses
geocoder.batchGeocode(['address1', 'address2'], function (err, results) {
// Return an array of type {error: false, value: []}
console.log(results) ;
});