Customizing e-commerce data for Google Analytics

Google Analytics allow tracking of shopping activity on e-commerce websites. To help you set up this functionality in Kentico, the system provides methods for macros, transformations and the API that return JSON data for products and orders in a suitable format. For more information, see Integrating Google Analytics Enhanced Ecommerce.

By default, the system’s methods do not set all of the optional data fields that can be processed by Google Analytics. If you wish to extend or completely change how the system creates e-commerce data for the purposes of Google Analytics, use the following customization approach:

  1. Open your Kentico project in Visual Studio.

  2. Create a custom class that inherits from one of the Google Analytics data helper classes.

    Class location

    We recommend adding custom classes as part of a new assembly (Class library project) in your Kentico solution. You need to add the appropriate references to both the assembly and the main Kentico web project.

  3. Override the methods of the helper class according to your custom requirements.

  4. Register your helper implementation using the RegisterCustomHelper assembly attribute.

When you reload the website, the system creates e-commerce JSON data using the custom implementations that you registered.

Google Analytics data helper classes

You can find the following helper classes in the CMS.Ecommerce namespace of the Kentico API.


Provides the following methods that you can override:

  • MapSKUInternal – creates data for a specified product (SKUInfo).

    • Must return a GtmData object containing the required keys (JSON field names) and values.
    • Customize this method to change the output of the GetGtmProductJson macro and transformation method, and the data of products returned by the GetGtmShoppingCartItemsJson macro method.
  • MapShoppingCartItemsInternal – creates data for a collection of products representing shopping cart content (IEnumerable<ShoppingCartItemInfo>).

    • Must return an IEnumerable collection of GtmData objects, each containing the required keys (JSON field names) and values.
    • Customize this method to change the output of the GetGtmShoppingCartItemsJson macro method.


Creates data for completed orders (purchases). Customize the methods in this class to change the output of the GetGtmPurchaseJson macro method.

Provides the following methods that you can override:

  • MapPurchaseInternal – creates the overall purchase data for a specified order (OrderInfo).

    • Must return a GtmData object containing the required keys (JSON field names) and values.
    • By default calls MapOrderInternal to create the data of the actionField field, and MapOrderItemsInternal to create the data of the products field.
  • MapOrderInternal – creates data representing a summary of the specified order (OrderInfo), including values such as the total revenue, tax, shipping, etc.

    • Must return a GtmData object containing the required keys (JSON field names) and values.
  • MapOrderItemsInternal – creates data representing all products within the specified order (OrderInfo).

    • Must return an IEnumerable collection of GtmData objects, each containing the required keys (JSON field names) and values.


Performs general serialization of GtmData objects into JSON strings. Affects the final output of methods from both the GtmProductHelper and GtmOrderHelper classes.

You can override the SerializeToJsonInternal method – one overload for individual objects (GtmData parameter) and another for collections of objects (IEnumerable<GtmData> parameter).

Customize the GtmDataHelper if you wish to replace or modify the default JSON serialization, which utilizes the JsonConvert.SerializeObject method provided by the Newtonsoft.Json library.

Creating conditional customizations

If you wish to return different JSON data for specific scenarios, you can use the purpose parameter, which is available for all methods of the Google Analytics data helper classes.

When calling the corresponding macro or transformation methods on your website, set the optional purpose parameter. For example:

{% GetGtmProductJson(SKUID, "", "searchImpressions") %}

You can then evaluate the purpose parameter within the method overrides in your custom helper classes, and branch your code according to the specified purpose.

Example – Adding coupon data for orders

The following example demonstrates how to customize the Google Analytics JSON data that the system creates for purchases (completed orders). The customization adds the coupon field to the actionField object in the purchase data, and sets the value to a comma-separated string containing all coupon codes applied to the order.

Start by preparing a separate project for custom classes in your Kentico solution:

  1. Open your Kentico solution in Visual Studio.

  2. Create a new Class Library project in the Kentico solution (or reuse an existing custom project).

  3. Add references to the required Kentico libraries (DLLs) for the new project:

    1. Right-click the project and select Add -> Reference.

    2. Select the Browse tab of the Reference manager dialog, click Browse and navigate to the Lib folder of your Kentico web project.

    3. Add references to the following libraries (and any others that you may need in your custom code):

      • CMS.Base.dll
      • CMS.Core.dll
      • CMS.DataEngine.dll
      • CMS.Ecommerce.dll
  4. Reference the custom project from the Kentico web project (CMSApp or CMS).

  5. Edit the custom project’s AssemblyInfo.cs file (in the Properties folder).

  6. Add the AssemblyDiscoverable assembly attribute:

     using CMS;

Continue by creating a custom implementation of the GtmOrderHelper class:

  1. Add a new class under the custom project.

  2. Make the class inherit from GtmOrderHelper.

  3. Register the class using the RegisterCustomHelper assembly attribute.

  4. Override the class’s MapOrderInternal method and return a GtmData object containing data according to your custom requirements:

     using System;
     using System.Collections.Generic;
     using System.Linq;
     using CMS;
     using CMS.Ecommerce;
     // Registers the CustomGtmOrderHelper class to replace the default GtmOrderHelper
     [assembly: RegisterCustomHelper(typeof(CustomGtmOrderHelper))]
     public class CustomGtmOrderHelper : GtmOrderHelper
         /// <summary>
         /// Maps the specified OrderInfo object to a GtmData object, containing data suitable for Google Analytics.
         /// The GtmData object is then serialized into a JSON string, which is returned by the appropriate macro or API method.
         /// </summary>   
         protected override GtmData MapOrderInternal(OrderInfo order, object additionalData = null, string purpose = null)
             if (order == null)
                 throw new ArgumentNullException(nameof(order));
             // Adds the default order data
             var customOrderData = new GtmData();
             customOrderData.Add("id", order.OrderID);
             customOrderData.Add("revenue", order.OrderGrandTotal);
             customOrderData.Add("tax", order.OrderTotalTax);
             customOrderData.Add("shipping", order.OrderTotalShipping);
             // Parses the order's coupon code data
             CouponCodeCollection orderCouponCodes = CouponCodeCollection.Deserialize(order.OrderCouponCodes);
             if (orderCouponCodes != null)
                 // Gets all coupon codes applied to the order        
                 IEnumerable<ICouponCode> appliedCouponCodes = orderCouponCodes.AllAppliedCodes;
                 // Creates a comma separated string containing the coupon codes
                 string couponString = String.Join(",", appliedCouponCodes.Select(coupon => coupon.Code));
                 // Adds the coupon field to the order data
                 customOrderData.Add("coupon", couponString);
             // Merges the custom data with any additional JSON data provided by the additionalData parameter
             customOrderData = GtmPropertiesMerger.Merge(customOrderData, additionalData);
             return customOrderData;

    Calling the base method

    The example above fully overrides the default implementation of the MapOrderInternal method. If you only wish to extend the default functionality, you can simplify the customization by calling the base method to create the initial GtmData.

     GtmData customOrderData = base.MapOrderInternal(order, additionalData);
     customOrderData.Add("customField", "customValue");
  5. Save all changes and Build the custom project.

The customization ensures that the system sets the coupon field when creating the purchase JSON data for orders that contain at least one coupon code. For example, the GetGtmPurchaseJson macro method could now produce the following JSON output:

  "actionField": {
    "coupon": "CouponCode1,CouponCode2",
    "id": 123,
    "revenue": 46.99,
    "shipping": 3,
    "tax": 4