Implementing a mediation flow

The entry and exit points, or endpoints of the mediation flow component are defined by the source interfaces and target references. The first step in building a mediation flow is determining the source operation.

1. If the mediation flow does not have a source interface, click Add interface to add an interface.
2. Click an operation in the source interface to open the request flow.

   A request flow begins with an input node on the left, which represents the source operation. The flow proceeds sequentially from left to right.

3. Next, determine the end point for the flow.
   1. If you want to invoke a target operation at the end of the request flow, and process the returning message in a response flow, drop a Callout from the palette onto the request flow, and select a reference and operation from the list that is presented. A Callout appears on the canvas and a response node is created. The message sent by the target operation will be returned to the response flow.
   2. If you want to invoke a target operation from within the request flow, drop a Service Invoke primitive from the palette onto the request flow, and select a reference and operation from the list that is presented. No response node is created. The message sent by the target operation will be returned to the request flow.
   3. If you want to return the message to the source after processing, right click the canvas and select Show Input Response. An Input Response is created in the request flow.
4. Drop mediation primitives from the palette onto the editor from left to right in the sequence that you want them to be invoked in the flow, between the input and callout or input response nodes.
5. Wire the primitives together.
6. Set the properties of each primitive to determine how the primitive will process the message. To edit a property, right click a primitive or node and select Show in Properties.
7. If you used a callout, click the Response flow tab at the top of the editor. The Callout Response is the entry point of the response flow, and the Input Response returns the message to the source.
8. Build a response flow in the same manner as you built the request flow.
9. Build an error flow to capture unhandled exceptions. You can either use mediation primitives such as Message Logger or you can define your error handling logic in a reusable subflow. If you want to return the error information to the source, wire the Input Response at the end of the error flow.