Adding Operational Branches to Message Flows

When message flows define Web Services Description Language (WSDL)-based proxy services, operation-specific processing is required. Instead of configuring a branching node based on operations manually, ALSB provides a minimal configuration branching node that automatically branches based on operations. In other words, when you create an operational branch node in a message flow, you can quickly build your branching logic based on the operations defined in the WSDL because the ALSB Console presents those operations in the branch node configuration page.

A branch node allows processing to proceed along exactly one of several possible paths. Branching is driven by an XPath-based switch table. Each branch in the table specifies a condition (for example, <500) that is evaluated in order down the message flow against a single XPath expression (for example, ./ns: PurchaseOrder/ns:totalCost on $body). Whichever condition is satisfied first determines which branch is followed. If no branch condition is satisfied, then the default branch is followed. A branch node may have several descendants in the message flow: one for each branch, including the default branch.

Before you begin

These instructions assume you are already editing a message flow in the Edit Message Flow page, as explained in Creating, Editing, and Viewing Message Flows.

To add an operation branch to a message flow

  1. Click a Pipeline Pair Node icon or a Branch Node icon, then click Create Operational Branch. The operational branch node is added, and any existing nodes after the inserted branch node are moved to the default branch of the new operational branch node.
  2. To change the default name and add a description for the branch node, do the following:
    1. Click the  Operational Branch icon, then click Edit Name and Annotation.
    2. Change the name and description, as desired.
    3. Click Save.
  3. To add branch definitions, click the  Operational Branch icon, then click Edit Branch. The Edit Branch Node page is displayed.
  4. In the Operation Branch Definitions panel, select a service operation.
  5. Optionally, under Options:
    • Click Add a New Branch to add a new branch definition to this branch node.
    • Click Delete this Branch to delete a branch definition.
    • Click Move Branch Up or click Move Branch Down to change the positions of branch definitions. This option displays only when more than one branch definition exists.
  6. Click Save.
  7. On the Edit Message Flow page, continue to construct the message flow, as described in Creating, Editing, and Viewing Message Flows.
  8. Click Save to commit the updates in the current session.
  9. To end the session and deploy the configuration to the run time, click Activate under Change Center.