Authentication for ebay's seller and use Trading Api for getting seller information

In this blog i am going to describe how to use Trading Api of Ebay for getting seller information.

We will proceed it in two parts -
1. Ebay Authentication.
2. Fetch seller information from Treding Api.

1. Ebay Authentication.

We have to do ebay authentication for verifying the seller. For this we will use omniauth-ebay gem.


So, in Gemfile :-

gem 'omniauth-ebay'

Now add omniauth initializer in config/initializers/omniauth.rb -

Rails.application.config.middleware.use OmniAuth::Builder do
  provider :ebay, "runame", "devid", "appid", "certid", "siteid", "environment", "auth_type"
end

"runame", "devid", "appid", "certid" these details you can find by going into your developer's account at eBay DevZone.

"siteid" - "siteid" represent your country or zone. You can obatain this from ebay.

"environment" - Here you can defined your environment as :production or :sandbox .

"auth_type" - If you want authenticate user every time than you have to define it as 'SignIn' .

After these set up you have to set routes path for ebay oauth callback. So, in routes.rb -

get '/auth/ebay/callback' => 'your_controller#your_method', as: 'ebay_callback'

Now you will be able to access the omniauth session data by accessing

request.env['omniauth.auth']

For token - request.env["omniauth.auth"]['credentials']['token']

2. Fetch seller information from Treding Api.

For getting seller data ebay provides Treding Api. We can use ebay_client gem. it provide lightweight eBay Trading API Client -

In Gemfile :-

 gem 'ebay_client', '~> 0.2.0'

In config/ebay_client.yml :-

development: &sandbox
  api_keys:
    - token: '<YOUR SANDBOX AUTHENTICATION TOKEN>' # we will set token later accourding to User
      devid: '<YOUR SANDBOX DEV ID>'
      appid: '<YOUR SANDBOX APP ID>'
      certid: '<YOUR SANDBOX CERT ID>'

test:
  <<: *sandbox

production:
  api_keys:
    - token: '<YOUR LIVE AUTHENTICATION TOKEN>' # we will set token later accourding to User
      devid: '<YOUR LIVE DEV ID>'
      appid: '<YOUR LIVE APP ID>'
      certid: '<YOUR LIVE CERT ID>'

Now, we have to make user specific yml file so we can set user's token. For this we will generate a Model EbayConfig -

In app/model/ebay_config

require 'yaml'
class EbayConfig < ActiveRecord::Base
  belongs_to :user, inverse_of: :ebay_config

  validates :app_id, :dev_id, :cert_id, :token, presence: true

  ######################### CallBacks##########################
  after_create :create_user_yml

  def self.user_ebay_data(user, user_token) #Pass the value of user as current_user and user_token of request.env["omniauth.auth"]['credentials']['token']
    data = YAML::load_file('config/ebay_client.yml')
    app_id = data["production"]["api_keys"].first["appid"]
    dev_id = data["production"]["api_keys"].first["devid"]
    cert_id = data["production"]["api_keys"].first["certid"]
    token = user_token
    @ebay_config = user.build_ebay_config(app_id: app_id, dev_id: dev_id, cert_id: cert_id, token: token)
    @ebay_config.save
  end

  def create_user_yml
    _user_yml = {"production" => create_user_config_hash}

    _yml_file = File.join(Rails.root, 'ebay_ymls', "#{self.user_id}_ebay_config.yml")
    File.open(_yml_file, "wb") do |file|
      file.write(_user_yml.to_yaml)
    end
  end

  def create_user_config_hash
    {
        api_keys: [{
                       appid: app_id,
                       devid: dev_id,
                       certid: cert_id,
                       token: token
                   }]
    }
  end

end

Now we have to intialize the ebay_client for specific user, For this we will create a module

require 'ebay_client'
module EbayGlue
  class EbayConnector
    attr_accessor :ebay_client

    def initialize(user_id)
      configurations = EbayClient::Configuration.load Rails.root.join('ebay_ymls', "#{user_id}_ebay_config.yml")
      configuration = configurations['production']
      @ebay_client = EbayClient::Api.new configuration
    end

  end
end

Now you can get @ebay_client and it will provide all the information

ex- @ebay_client.get_store.payload
    @ebay_client.get_user


Thats it !!!!!