Commerce Foundation Operation Sequences

Microsoft Multi-Channel Commerce Foundation request processing components are grouped into operations. The Commerce Server 2009 broker controls the execution of the operation through the Microsoft Multi-Channel Commerce Foundation operation sequence. The operation sequence of the operation must contain one or more components to handle the operation.

Operation Sequence Component

To create a component of the specific type, you must implement the IOperationSequenceComponent interface. Microsoft Multi-Channel Commerce Foundation defines the following interface for this purpose.

public interface IOperationSequenceComponent 
{
   void Execute( CommerceOperation operation, 
                 OperationCacheDictionary operationCache, 
                 CommerceOperationResponse response);
}

Or, you could create an operation sequence component that simply inherits from the OperationSequenceComponent class. This will provide strongly typed operation methods along with all of the necessary tracing capabilities.

The operation sequence execution starts with the first operation sequence component and moves through them iteratively in the order defined in the configuration. A Microsoft Multi-Channel Commerce Foundation operation can have any number of components defined for the operation sequence. You can customize the business rules of an operation simply by manipulating the content of the operation sequence by either replacing components or add your own. All the components in the operation sequence can be replaced and any number of the components can be added to it as long as you implement the IOperationSequenceComponent interface.

Commerce Foundation Operation Configuration

An example of the configuration section that defines a Microsoft Multi-Channel Commerce Foundation operation is shown below. The configuration sections reflect the object model described above. A MessageHandler contains the OperationSequence that consists of one or more components defined in a hierarchical format.

<MessageHandler name="CommerceQueryOperation_Product"
responseType="Microsoft.Commerce.Contracts.Messages.CommerceQueryOperationResponse, Microsoft.Commerce.Contracts, Version=1.0.0.0, Culture=neutral,PublicKeyToken=31bf3856ad364e35">
  <OperationSequence>
    <Component name="Product Query Processor" type="Microsoft.Commerce.Providers.Components.ProductLoader, Microsoft.Commerce.Providers, Version=1.0.0.0, Culture=neutral,PublicKeyToken=31bf3856ad364e35">
      <Component name="Cross-Sell Provider" type="Microsoft.Commerce.Providers.Components.ProductCommerceServerRelationshipProcessor, Microsoft.Commerce.Providers, Version=1.0.0.0, Culture=neutral,PublicKeyToken=31bf3856ad364e35">
        <Configuration
          customElementName="CommerceServerRelationshipConfiguration"
          customElementType="Microsoft.Commerce.Providers.Components.CommerceServerRelationshipConfiguration, Microsoft.Commerce.Providers, Version=1.0.0.0, Culture=neutral,PublicKeyToken=31bf3856ad364e35">
          <CommerceServerRelationshipConfiguration commerceServerRelationshipName="CrossSell" internalRelationshipName="CrossSells"/>
        </Configuration>
      </Component>
      <Component name="Up-Sell Provider" type="Microsoft.Commerce.Providers.Components.ProductCommerceServerRelationshipProcessor, Microsoft.Commerce.Providers, Version=1.0.0.0, Culture=neutral,PublicKeyToken=31bf3856ad364e35">
        <Configuration
            customElementName="CommerceServerRelationshipConfiguration"
            customElementType="Microsoft.Commerce.Providers.Components.CommerceServerRelationshipConfiguration, Microsoft.Commerce.Providers, Version=1.0.0.0, Culture=neutral,PublicKeyToken=31bf3856ad364e35">
          <CommerceServerRelationshipConfiguration commerceServerRelationshipName="UpSell" internalRelationshipName="UpSells"/>
        </Configuration>
      </Component>
      <Component name="Product Variant Provider" type="Microsoft.Commerce.Providers.Components.ProductVariantProcessor, Microsoft.Commerce.Providers, Version=1.0.0.0, Culture=neutral,PublicKeyToken=31bf3856ad364e35"/>
      <Component name="ProductAncestorCategoryProcessor" type="Microsoft.Commerce.Providers.Components.ProductAncestorCategoryProcessor, Microsoft.Commerce.Providers, Version=1.0.0.0, Culture=neutral,PublicKeyToken=31bf3856ad364e35"/>
      <Component name="ProductCanonicalCategoryProcessor" type="Microsoft.Commerce.Providers.Components.ProductCanonicalCategoryProcessor, Microsoft.Commerce.Providers, Version=1.0.0.0, Culture=neutral,PublicKeyToken=31bf3856ad364e35"/>
      <Component name="ProductParentCategoryProcessor" type="Microsoft.Commerce.Providers.Components.ProductParentCategoryProcessor, Microsoft.Commerce.Providers, Version=1.0.0.0, Culture=neutral,PublicKeyToken=31bf3856ad364e35"/>
      <Component name="ProductPrimaryCategoryProcessor" type="Microsoft.Commerce.Providers.Components.ProductPrimaryCategoryProcessor, Microsoft.Commerce.Providers, Version=1.0.0.0, Culture=neutral,PublicKeyToken=31bf3856ad364e35"/>
      <Component name="ProductRelatedCategoryProcessor" type="Microsoft.Commerce.Providers.Components.ProductRelatedCategoryProcessor, Microsoft.Commerce.Providers, Version=1.0.0.0, Culture=neutral,PublicKeyToken=31bf3856ad364e35"/>
      <Component name="ProductRelatedProductProcessor" type="Microsoft.Commerce.Providers.Components.ProductRelatedProductProcessor, Microsoft.Commerce.Providers, Version=1.0.0.0, Culture=neutral,PublicKeyToken=31bf3856ad364e35"/>
      <Component name="ProductInventoryItemsProcessor" type="Microsoft.Commerce.Providers.Components.ProductInventoryItemsProcessor, Microsoft.Commerce.Providers, Version=1.0.0.0, Culture=neutral,PublicKeyToken=31bf3856ad364e35"/>
      <Component name="Product catalog relationship" type="Microsoft.Commerce.Providers.Components.ProductCatalogRelationshipProcessor, Microsoft.Commerce.Providers, Version=1.0.0.0, Culture=neutral,PublicKeyToken=31bf3856ad364e35"/>
      <Component name="Product base catalog relationship" type="Microsoft.Commerce.Providers.Components.ProductBaseCatalogRelationshipProcessor, Microsoft.Commerce.Providers, Version=1.0.0.0, Culture=neutral,PublicKeyToken=31bf3856ad364e35"/>
      <Component name="Product Discounts Relationship" type="Microsoft.Commerce.Providers.Components.CatalogEntityDiscountsProcessor, Microsoft.Commerce.Providers, Version=1.0.0.0, Culture=neutral,PublicKeyToken=31bf3856ad364e35" />
    </Component>
  </OperationSequence>
</MessageHandler>

In the MessageHandler element, the name attribute maps an incoming operation request to the appropriate Microsoft Multi-Channel Commerce Foundation operation sequence, whose component classes process the request and generate the response. The name of a Microsoft Multi-Channel Commerce Foundation MessageHandler consists of two parts separated by an underscore character. The first part is the name of the operation type and the second part is the model name of the commerce entity upon which the operation is performed.

The name of the operation is obtained from the Name property of the Type object for the operation of the request. This name is stripped of any namespace information. This allows you to use the same configuration sections for the operations that handle the requests that are based on the classes derived from the Operation as long as the name are the same as the Microsoft Multi-Channel Commerce Foundation class. The namespace of course should be different from the Microsoft Multi-Channel Commerce Foundation namespace. However, if you decide to use different names for the derived types you will have to change the MessageHandler names in the configuration file.

The Component can be expressed as a hierarchy that represents the dependencies between the components. In the example shown, all components depend on the Product Query Processor component.

The following are the MessageHandler element attributes:

The following are the OperationSequence element attributes:

The following are the Component element attributes:

The following are the Configuration element attributes:

The classes specified through the type attribute of the Component element must implement the proper interface described above. If the types registered as components in the Operation section fail to implement the proper interface, the InvalidCastException will be thrown during runtime. Every operation component must have a public default (parameterless) constructor.

Commerce Foundation Broker Interpretation of the Operation Sequence

The Broker is a key component of Commerce Server 2009 that maps an incoming request to the Microsoft Multi-Channel Commerce Foundation operation and executes the corresponding operation sequence that processes the request and generates the operation's response.

In order to do so, the Broker implements the following algorithm:

1. The Broker creates the OperationCacheDictionary object. See the sections below on how the operation components can use the OperationCacheDictionary.

2. Based on the type of the CommerceOperation objects in the CommerceRequest being processed, the Broker creates the response object.

3. The Broker checks the type of the Request object and the type of the model contained in this object to determine the name of the message handler operation responsible for handling this request.

4. If this is the first time the operation is to be executed, the Broker loads the operation sequence component type information from the configuration file (see the previous section on the details of the operation configuration) and stores it in the internal cache. Dependency checking is performed at this point.Otherwise, on the subsequent calls to the operation, the Broker retrieves the operation component type information from the internal cache.

5. Using the type information obtained in the previous step, the Broker instantiates all the configured operation sequence components using the Reflection mechanism.

6. The Broker begins a transaction if the operation sequence has been configured as transactional.

7. The Broker invokes, in turn, each component in the order defined in the configuration file.

8. The Broker finishes the execution of the operation by returning the Response object updated by the operation sequence components.

In This Section

• Commerce Foundation Transactions

See Also

Other Resources

Developing with the Multi-Channel Commerce Foundation

Commerce Foundation Transactions

Commerce Foundation Operation Sequence Extensibility Point