BizTalk ESB Toolkit: Dynamic Resolvers in ESB Itinerary Process

In this article, I would demonstrate the features of dynamic resolvers by using BREs. In previous post, we had used a static itinerary resolver, now the itinerary will be resolved dynamically by the OnRamp. And itinerary will be able to do a dynamic transformation of the message received at OnRamp then based on the transformed message we would route the message to destination system. 

ESB Flow:
{OnRamp[BRI Resolver, Receive Port] -->Messaging Extender[BRE Map Resolver]}-->Off-Ramp Extender[BRE Routing Resolver] -->OffRamp[Dynamic Send Port]

The main role of the ESB Itinerary Selector is to configure an Itinerary Resolver, and here we would use BRI resolver as shown below. 

Itinerary Resolver:

• Rule 1: If Message from RequstorA or RequestB then Set Itinerary Name as ESB.DynamicRoutingSlip; halt and exit the BRE execution. 
• Rule 2: if any other messages received Set Itinerary Name ESB.StaticRoutingSlip; halt and exit the BRE execution. 

BRE Map Resolver: 
Let’s say we receive an inbound message and we would evaluate message and select the map as show below,

• Rule 1: If Message from RequstorA then Set Transform Type as RequestAToCanoical; halt and exit the BRE execution. 
• Rule 2: If Message from RequstorB then Set Transform Type as RequestBToCanoical; halt and exit the BRE execution. 

Routing Resolver: 

This BRE would use transformed message,

• Rule 1: If Transformed Message from RequstorA then Set End Point Outbound Transport Location and Set End Point Outbound Transport Type accordingly; halt and exit the BRE execution. 
• Rule 2: If Transformed Message from RequstorB then Set End Point Outbound Transport Location and Set End Point Outbound Transport Type accordingly; halt and exit the BRE execution. 

Itinerary Configuration:

• OnRamp, choose the application and then select the Receive-Port. 
• Use the itinerary service as a messaging extender with a BRE resolver. 
• Use the itinerary service as a off Ramp extender with a BRE resolver. 
• In Off Ramp, choose the application and then select the dynamic port. As shown, connect all the components.

Conclusion 

In this article, I covered principles of the itinerary as well as I illustrated how to develop an itinerary process with a dynamic resolver using BREs.