CCAvenue Ruby GEM Usage

application_controller.rb

# application_controller.rb

    # Create an instance with merchantid, workingkey and redirect url as parameter
    def ccavenue
        return @ccavenue = Ccavenue::Payment.new(<TODO: MERCHANT ID>,<TODO: MERCHANT WORKING KEY>,<TODO: REDIRECT URL>)
    end

ccavenue_confirmation.rb

# CCAvenue confirmation method. This is called by CCAvenue upon callback.

    # Method post 
    def payment_confirm  
        # parameter to response is encrypted reponse we get from CCavenue
        authDesc,verify,data = ccavenue.response(params['encResponse'])
        
        # Return parameters:
        #   Auth Description: <String: Payment Failed/Success>
        #   Checksum Verification <Bool: True/False>
        #   Response Data: <HASH/Array: Order_id, amount etc>
        
        order_Id = data["Order_Id"][0]
    end

order_page_redirect.rb

# Orders page from which user will be redirected to payment gateway.

	def send_to_ccavenue
        # Merchant id needed in view
        @CCAVENUE_MERCHANT_ID = <TODO: MERCHANT ID>
        
        # CCAvenue requires a new order id for each request 
        # so if transaction fails we can use #same ones again accross our website.
        order_id =  Time.now.strftime('%d%m%H%L') + <TODO: Order Id>
        
        # Parameters:
        #
        #   order_id
        #   price
        #   billing_name
        #   billing_address
        #   billing_city
        #   billing_zip
        #   billing_state
        #   billing_country
        #   billing_email
        #   billing_phone
        #   billing_notes
        #   delivery_name
        #   delivery_address
        #   delivery_city
        #   delivery_zip
        #   delivery_state
        #   delivery_country
        #   delivery_email
        #   delivery_phone
        #   delivery_notes
        #
        #
        #   Mandatory - order_id,price,billing_name,billing_address,billing_city,billing_zip,billing_state,billing_country,billing_email,billing_phone
        #   Optional - billing_notes,delivery_name,delivery_address,delivery_city,delivery_zip,delivery_state,delivery_country,delivery_email,delivery_phone,delivery_notes
        
        # Creating encrypted data
        @encRequest = ccavenue.request(order_id,<TODO: Price>,@order.full_name,"#{@order.address1} ,#{@order.address2}",@order.city,@order.zip,@order.state,@order.country,@order.email,@order.phone)
        render "<TODO: Redirect Page>"
	end

redirect_ccavenue.html

<!-- A redirect view has to be renderend that creates a post request for the payment gateway.-->

    <form id="redirect" method="post" name="redirect" action="http://www.ccavenue.com/shopzone/cc_details.jsp">
        <input type="hidden" name="encRequest" value="<%= @encRequest %>">
        <input type="hidden" name="Merchant_Id" value="<%=@CCAVENUE_MERCHANT_ID%>">
    </form>
    
    <script>
        document.getElementById("redirect").submit();   
    </script>

You can refer documentation here