Using Ruby Gem That Uses an API - Setting Up Client - ruby-on-rails

Question

I am using Ruby on Rails. I am trying to implement https://www.kraken.com/help/api
Incase it isn't obvious, my knowledge of implementing API's and gems is very basic.
I go to the "example-api-code" paragraph and I get to https://github.com/leishman/kraken_ruby
I include the gem and do the bundle.
Now we get to "Usage" "Create A Client"
I assume I put the following in config/kraken.rb
API_KEY = '3bH+M/nLp......'
API_SECRET = 'wQG+7Lr9b.....'
kraken = Kraken::Client.new(API_KEY, API_SECRET)
time = kraken.server_time
time.unixtime #=> 1393056191
I wanted to test something simple, such as displaying the time.
I put the following code in my views/welcome/index.html.erb file, but then I get an error.
<p><%= kraken.server_time %></p>
-> ActionView::Template::Error (undefined local variable or method `kraken' for #<#<Class:0x007f95c6246ba8>:0x007f95c6245eb0>):
Trying this code in my html.erb file and it gives me another error
<p><%= #kraken.server_time %></p>
-> ActionView::Template::Error (undefined method `server_time' for nil:NilClass):
-------------------------------------------------------------------------------
EDIT: Solutions Attempts, TLDR NameError (uninitialized constant...
# Gladis
Using your solution I get this error
->! Unable to load application: SyntaxError: /app/app/controllers/welcome_controller.rb:5: dynamic constant assignment
-> API_KEY = '...'
So I tried
def index
#kraken = Kraken::Client.new('3bH+M/nLp...', 'wQG+7Lr9b...')
time = #kraken.server_time
time.unixtime #=> 1393056191
end
and got this new error
NameError (uninitialized constant WelcomeController::Kraken):
app/controllers/welcome_controller.rb:5:in `index'
# Pavel Tkackenko
Your first solution (wrapping in singleton-like class) gives me this error.
ActionView::Template::Error (uninitialized constant ActionView::CompiledTemplates::KrakenClient):
app/views/welcome/index.html.erb:1:in `_app_views_welcome_index_html_erb__3584347874708863751_70226442404480'
1: <p><%= KrakenClient.get.server_time %></p>
Your second solutions (monkey-patch) gives me the this error.
ActionView::Template::Error (uninitialized constant ActionView::CompiledTemplates::Kraken):
1: <p><%= Kraken.client.server_time %></p>
app/views/welcome/index.html.erb:1:in `_app_views_welcome_index_html_erb___3719740865851336982_69820265644620'
Moving /config/kraken.rb to /config/initializers/kraken.rb using Pavel's method
Wrapping it in singleton-like class gives me this error (infact, it doesn't even let me host the server)
->When I host it on my local computer with bin/rails server
/config/initializers/kraken.rb:6:in `<class:KrakenClient>': uninitialized constant KrakenClient::Kraken (NameError)
/config/initializers/kraken.rb:1:in `<top (required)>'
->When I host it on heroku
Running: rake assets:precompile
rake aborted!
NameError: uninitialized constant KrakenClient::Kraken
/config/initializers/kraken.rb:5:in `<class:KrakenClient>'
/config/initializers/kraken.rb:1:in `<top (required)>'
...
/config/environment.rb:5:in `<top (required)>'
With monkey-patch I get this error
ActionView::Template::Error (uninitialized constant Kraken::Client):
1: <p><%= Kraken.client.server_time %></p>
config/initializers/kraken.rb:8:in `client'
app/views/welcome/index.html.erb:1:in `_app_views_welcome_index_html_erb___577296263292451462_70097201303100'
If you got it to work on your computer, I would be happy to use your code as a skeleton (I am assuming this will be easier than figuring out what's wrong on my side).

Answer 1

Put this code in WelcomeController.rb
def index
API_KEY = '3bH+M/nLp......'
API_SECRET = 'wQG+7Lr9b.....'
#kraken = Kraken::Client.new(API_KEY, API_SECRET)
time = #kraken.server_time
time.unixtime #=> 1393056191
end
In view under this controller put:
<p><%= #kraken.server_time %></p>

Answer 2

kraken = Kraken::Client.new(API_KEY, API_SECRET)
kraken here is local variable. If you put it into config/kraken.rb, it will not be accessible outside.
There are different solutions. One is to wrap it in singleton-like class:
# config/initializers/kraken.rb
class KrakenClient
API_KEY = '3bH+M/nLp......'
API_SECRET = 'wQG+7Lr9b.....'
##config = Kraken::Client.new(API_KEY, API_SECRET)
def self.get
##config
end
end
# index.html.erb
<p><%= KrakenClient.get.server_time %></p>
Another one approach is to monkey-patch Kraken itself:
# config/initializers/kraken.rb
class Kraken
API_KEY = '3bH+M/nLp......'
API_SECRET = 'wQG+7Lr9b.....'
class << self
def client
#client ||= Kraken::Client.new(API_KEY, API_SECRET)
end
end
end
# index.html.erb
<p><%= Kraken.client.server_time %></p>