I tried to get the distance from the address string to the nearest station with ruby

I tried to get the information of the nearest station from the address with ruby.

Roughly what I did

1. Get latitude / longitude from address with Yahoo API
2. Get the nearest station information from latitude and longitude with Heart Rails API

Execution environment

1. ruby2.7.2
2. mac catalina
3. Execution date and time 2021/01/01

1. Get latitude / longitude from address with Yahoo API

1.1 Get yahoo app ID

Get here https://e.developer.yahoo.co.jp/dashboard/

1.2 Request

-Encode the requested address to url ・ Request with open-uri The response looks like this

1.3 Scraping latitude and longitude from response

Get it using REXML. It is stored in the coordinates tag.

2. Get the nearest station information from latitude and longitude with Heart Rails API

2.1 Request with the latitude and longitude obtained in 1.

Click here for url

http://express.heartrails.com/api/xml?method=getStations&x=#{lon}&y=#{lat}"

The response returned is like this (multiple returns in order of closeness: eyes :)

2.2 Scraping the returned nearest station information

As mentioned above, the station information is included in the station tag. Specify the first station tag because it contains multiple station information.

Completed code

The code looks like this.

require 'open-uri'
require 'uri'
require "rexml/document"

## 1. request Yahoo API

### 1.1
YAHOO_APP_ID = '[Yahoo app_id]'

### 1.2
ADDRESS ='1-1 Chiyoda, Chiyoda-ku, Tokyo'
p ADDRESS
query = URI.encode_www_form(query: ADDRESS) ##encoding

request_url = "https://map.yahooapis.jp/geocode/V1/geoCoder?appid=#{YAHOO_APP_ID}&#{query}"

### 1.3 
res = OpenURI.open_uri(request_url)

doc = REXML::Document.new(res.read)
coordinates = doc.elements['YDF/Feature/Geometry/Coordinates'].text
lon,lat = coordinates.split(',')

p "longitude= #{lon} ,latitude= #{lat}"

## 2. Heart Rails API

### 2.1 1.Request with the latitude and longitude obtained in
heart_rails_request_url = "http://express.heartrails.com/api/xml?method=getStations&x=#{lon}&y=#{lat}"


### 2.2 Scrap the returned nearest station information
res = OpenURI.open_uri(heart_rails_request_url)
doc = REXML::Document.new(res.read)

station = doc.elements['response/station[1]']
name = station.elements['name'].text
line = station.elements['line'].text
distance = station.elements['distance'].text
p name
p line
p distance

Execution result

The result of requesting the nearest station at the Imperial Palace (1-1 Chiyoda, Chiyoda-ku, Tokyo).

"longitude= 139.75381447 ,latitude= 35.68382285"
"Sakuradamon"
"Tokyo Metro Yurakucho Line"
"740m"