The default API is a good start, but it conforms to your schema. Usually, you will want to customize/shape your API. For example, API agreements with partners typically do not match internal schema definitions. The resources that you explicitly define in API Creator provide key services to map API agreements onto your database and logic:

Choose/rename columns, which is a simple approach to mapping and transformation logic. In the previous image, 
PartnerOrder.Order
ID
 
 is aliased to 
Order
Number
 
.
Specify resource nesting so that B2B requests can include multiple kinds of data, such as the Order and Items.
Use non-persistent attributes (NPA) in resources. For example, in the 
OrderSummary
 resource, the SalesRep's 
fullName
 is an NPA.
Combine parent subresources into the containing resource. For example, in the 
OrderSummary
 resource, the 
Product
 information appears with the 
Order_DetailList
 properties.
The resources that you explicitly define in API Creator reuse the logic on the underlying tables.

For more information:

About the resources that you explicitly define in API Creator, see Customize your API.
About data integration and resources to define partner object mappings, see Logic Patterns.
About combined resources, including subresources, see Manage Subresources.
About non-persistent attributes, see Manage Non-Persistent Attributes.

Verify that orders do not exceed customers' credit limits.
Provide discounts for healthy orders.
Post requests to the 
Pavlov
 supplier when orders are received for their products.

   

Check Credit.
 Rolls up items and orders to verify that the customer's credit limit is not exceeded. (If a validation is exceeded, the request results in an exception and the transaction is rolled back.)
Healthy Food Discount.
 Provides a discount to customers ordering things like fruits and fish.
Supplier Alert.
 When orders are detected for the
Pavlov
supplier, the business agreement requires that the order is posted to the
Pavlov
supplier.
Shipper Alert.
 When orders have an assigned shipping company, alert them to order changes.

About the list of rules, see Quick Reference.
About non-persistent attributes, see the Healthy Food Discount topic logic in Manage Non-Persistent Attributes.
About generated key handling (for example, creating an order number and placing it into the order details), see Automatic Key Generation.

About viewing an example of Bill of Materials that are solved with a few rules, see the Reactive Logic Tutorial.
About a list of the JavaScript extension points, including their supplied context, see Quick Reference.
About logic event rule types, see Event Rule Types.

   

var shipper = row.FK_Orders_Shippers;
if (shipper !== null) {    // resource defines transform: cols, aliases, related objects
   var transform = logicContext.transformCurrentRow("ShipperAPIDef");
   B2B.sendToWebHook(transform, shipper.webHookURL);
}

Transformation logic.
 A common integration pattern is to use resources for mapping and translation, leveraging their ability to choose/rename attributes and related objects. The 
logicContext
 object's 
transformCurrentRow
 method transforms a table row to a resource instance and is typically called in an event rule. This method provides transformation logic to select/rename attributes and related objects. The 
ShipperAPIDef
 resource defines the format of the post.
Event handling. 
Event rules react to database changes, regardless of the execution path.
Posting.
 The post is done in the 
sendToWebHook()
 method.
Webhook target. 
Shippers can register for webhooks by way of self-service APIs that set 
shipper.webHookURL
.
For more information about this pattern, see the "Security" section in Explore B2B.

For more information:

About the 
transformCurrentRow
 method, see transformCurrentRow Method.
About row objects, see Row Objects.
About integration, see Integration.
About table commit event rules and row commit logic cycles, see Logic Execution.
About the 
SysUtility
 JavaScript object and the methods it includes, see The SysUtility Object.
About maintaining transaction state, see The Request object.
About using resources for mapping and transformation logic using the 
transformCurrentRow
 method, see The logicContext Object.

Extensibility: Loadable Libraries

If you detect patterns in your logic, you can provide reusable solutions that rules can invoke. The code in the following image provides a reusable function that implements a webhook: