How to integrate a simple bitcoin API into a Rails app

Question

I am new to API's and backend development in general and have been trying for a few hours now to figure out how to do something simple like call the current bitcoin market price into my Rails app.

I tried referencing http://blockchain.info/ticker with the following code in my model

require 'rest-client'
require 'json'

base_url = "http://blockchain.info/ticker"
response = RestClient.get base_url
data = JSON.load response
cool = data[0]["CNY"]
@test = JSON.pretty_generate cool

and then put this in my view

<%= @test %>

I know this is way off but I'm at a loss and figured I would see if someone could provide a good resource or maybe get me going in the right direction. Many thanks

Answer 1

Dude, its all working good.

Replace data[0]["CNY"] with data["CNY"], thats all.

To get more handle, execute these lines 1 by 1 in irb,

Just like this,

1.9.3p385 :001 > require 'rest-client'
 => true 
1.9.3p385 :002 > require 'json'
 => true 

1.9.3p385 :004 > base_url = "http://blockchain.info/ticker"
 => "http://blockchain.info/ticker" 

1.9.3p385 :005 > response = RestClient.get base_url

1.9.3p385 :006 > data = JSON.load response

1.9.3p385 :007 > cool = data["CNY"]
 => {"15m"=>5519.13613, "last"=>5519.13613, "buy"=>5578.16433, "sell"=>5853.54832, "24h"=>5616.47, "symbol"=>"¥"} 

1.9.3p385 :008 > @test = JSON.pretty_generate cool
 => "{\n  \"15m\": 5519.13613,\n  \"last\": 5519.13613,\n  \"buy\": 5578.16433,\n  \"sell\": 5853.54832,\n  \"24h\": 5616.47,\n  \"symbol\": \"¥\"\n}" 

1.9.3p385 :009 > p @test
"{\n  \"15m\": 5519.13613,\n  \"last\": 5519.13613,\n  \"buy\": 5578.16433,\n  \"sell\": 5853.54832,\n  \"24h\": 5616.47,\n  \"symbol\": \"¥\"\n}"
 => "{\n  \"15m\": 5519.13613,\n  \"last\": 5519.13613,\n  \"buy\": 5578.16433,\n  \"sell\": 5853.54832,\n  \"24h\": 5616.47,\n  \"symbol\": \"¥\"\n}"

Answer 2

I would recommend you use httparty which makes sending requests much simpler. With regards to your example, you could do

require 'httparty'
require 'json'

base_url = "http://blockchain.info/ticker"
response = HTTParty.get(base_url)
data = JSON.parse(response.body)
data.each_pair do |ticker, stats|
  pp "Ticker: #{ticker} - 15m: #{stats['15m']}"
end

Obviously I am pp (printing) out a string just to show the data. You would actually render the data in the view if you were to do a real implementation.