How to get the permanent token for Shopify (Rails)? - ruby-on-rails

Question

I am trying to authenticate my new Shopify app. First, my authenticate method redirects the shop owner to Shopify's authentication page:
def authenticate
ShopifyAPI::Session.setup({:api_key => "123", :secret => "456"})
session = ShopifyAPI::Session.new("someshop.myshopify.com")
redirect_to session.create_permission_url(["read_orders"], "https://myapp.com/shopify/post_authenticate?user=someshop")
end
Once the shop owner has approved the integration, the redirect uri triggers my post_authenticate method:
def post_authenticate
ShopifyAPI::Session.setup({:api_key => "123", :secret => "456"})
session = ShopifyAPI::Session.new("#{params[:user]}.myshopify.com")
token = session.request_token(:code => params[:code], :signature => params[:signature], :timestamp => params[:timestamp])
end
But the request_token method returns the following error:
#<ShopifyAPI::ValidationException: Invalid Signature: Possible malicious login>
I have read somewhere that you need to be in the same ShopifyAPI session while doing all of this, but it does not say so in the documentation. And the example app takes a very different approach than the documentation.

Answer 1

As per my comment, I utilize the omniauth methodology for authenticating. Here's a gist of the code for reference. https://gist.github.com/agmcleod/7106363317ebd082d3df. Put all the snippets below.
class ApplicationController < ActionController::Base
protect_from_forgery
force_ssl
helper_method :current_shop, :shopify_session
protected
def current_shop
#current_shop ||= Shop.find(session[:shop_id]) if session[:shop_id].present?
end
def shopify_session
if current_shop.nil?
redirect_to new_login_url
else
begin
session = ShopifyAPI::Session.new(current_shop.url, current_shop.token)
ShopifyAPI::Base.activate_session(session)
yield
ensure
ShopifyAPI::Base.clear_session
end
end
end
end
In my login controller:
def create
omniauth = request.env['omniauth.auth']
if omniauth && omniauth[:provider] && omniauth[:provider] == "shopify"
shop = Shop.find_or_create_by_url(params[:shop].gsub(/https?\:\/\//, ""))
shop.update_attribute(:token, omniauth['credentials'].token)
shopify_session = ShopifyAPI::Session.new(shop.url, shop.token)
session[:shop_id] = shop.to_param
redirect_to root_url
else
flash[:error] = "Something went wrong"
redirect_to root_url
end
end
config/initializers/omniauth.rb
Rails.application.config.middleware.use OmniAuth::Builder do
provider :shopify, Settings.api_key, Settings.api_secret,
scope: 'write_products,write_script_tags,read_orders',
setup: lambda { |env| params = Rack::Utils.parse_query(env['QUERY_STRING'])
env['omniauth.strategy'].options[:client_options][:site] = "http://#{params['shop']}" }
end
Then in your routes file, map the create action of your session appropriately:
match '/auth/shopify/callback', :to => 'login#create'
From there i use the shopify_session method as an around filter on the appropriate controllers.