geocoder-dadata

Why dadata?

• Amazing quality of Geocoding for territory of Russia
• Moderate pricing
• Lot's of other useful servicies like suggestions and others

Example

Forward geocoding

    const { Geocoder } = require('geocoder-dadata')
    const coder = new Geocoder({ api_token: 'YOUR DATATA API TOKEN', api_secret: 'YOUR DATATA API SECRET' })

    coder.geocode('Москва, Мичуринский пр-т, 9к1').then(resp => {

        if (resp.ok) {

            console.log('Geo coordinates:', resp.geo)
            console.log('Detailed response:', resp.results)
        }

        else {

            console.log('Request has failed')
            console.log('Check the full response from dadata:', resp)
            console.log('Or you can check response status only:', resp.status.code, resp.status.message)
        }
    })

Make it safe

To make your code safer put your API token and secret into environment variables DADATA_API_TOKEN и DADATA_API_SECRET and avoid passing it to the geocoder constructor as plain text in your code:

    const coder = new geocoder() //In this case your are expected to provide your API credebtials in DADATA_API_TOKEN и DADATA_API_SECRET variable before using geocoder constructor

Response caching

By default the geocoder automaticaly caches responses in memory. The cache is shared among all instances of the geocoder class that use the same API KEY. If you change an API key, it makes cached responses effectively invisible to other geocoder instances if they use other API keys.

If you would like a particular geocoder instance not to use caching you may provide it a { cached: false } option like so:

    const coder = new geocoder({ cached: false })
    // By default "cached" option is set to true

Batch request throttling

It's important to note that just like any other service provider dadata puts certain limits on how much requests you may send per second (10 requests per second). When it comes to batch processing, a pace keeping techniques comes into play. The geocoder-dadata client supports requests throttling by default so you can rest peacefully. If you send lots of requests to geocoder-dadata they will be arranged in a queue and scheduled to be sent at rate of 5 request per second. If you want to tweek internal pace keeper by pace_limit option like so:

    const coder = new geocoder({ pace_limit: 10 })
        // This will limit the geocoder to 10 requests per second.
        // Put here whatever suits your contract with dadata
        // By default "pace_limit" equals to 5