Add new API v2 endpoint to support Braintree Token generation

app/controllers/spree/api/v2/braintree_client_token_controller.rb

@@ -0,0 +1,24 @@
+module Spree
+  module Api
+    module V2
+      class BraintreeClientTokenController < ::Spree::Api::V2::BaseController
+        include Spree::Api::V2::Storefront::OrderConcern
+        before_action :ensure_order
+
+        def create
+          gateway = if params[:payment_method_id]
+            Spree::Gateway::BraintreeVzeroBase.find(params[:payment_method_id])
+          else
+            Spree::Gateway::BraintreeVzeroBase.active.first
+          end
+
+          render json: {
+            client_token: gateway.client_token(spree_current_order, @current_api_user),
+            payment_method_id: gateway.id
+          }
+        end
+
+      end
+    end
+  end
+end

app/views/spree/shared/braintree_vzero/_dropin.js.erb

@@ -67,4 +67,3 @@ onError: function (error) {
   SpreeBraintreeVzero.enableSubmitButton();
   <%= render partial: 'spree/checkout/payment/braintree_vzero/dropin_on_error_callback', formats: [:js] %>
 }
-

config/initializers/extend_spree_permitted_checkout_attributes.rb

@@ -1,5 +1,12 @@
 module Spree
   module PermittedAttributes
     @@payment_attributes = [:amount, :payment_method_id, :payment_method, :braintree_token, :braintree_nonce]
+    @@source_attributes = [
+      :number, :month, :year, :expiry, :verification_value,
+      :first_name, :last_name, :cc_type, :gateway_customer_profile_id,
+      :gateway_payment_profile_id, :last_digits, :name, :encrypted_data,
+      # Add Braintree params to allow source to be created
+      :braintree_last_two, :braintree_card_type, :braintree_nonce
+    ]
   end
 end

config/routes.rb

@@ -3,5 +3,8 @@
     namespace :v1 do
       resource :braintree_client_token, only: :create, controller: 'braintree_client_token'
     end
+    namespace :v2 do
+      resource :braintree_client_token, only: :create, controller: 'braintree_client_token'
+    end
   end
 end