This text file contains sample code fragments from:
Chapter 19 - Composition Implementation Patterns
Book - SOA Design Patterns
Series - Prentice Hall Service-Oriented Computing Series from Thomas Erl
Site - www.soabooks.com


<scope name="InventoryMgmt">
  <faultHandlers>
    <catch faultName="ns2:NoSpaceAvailableFault">
      <compensate name="Compensate_Withdraw"/>
    </catch>
  </faultHandlers>
  <sequence name="Sequence_1">
    <scope name="WithdrawInventory">
      <compensationHandler>
        <invoke name="undoWithdrawInventory"
          partnerLink="InventorySystem"
          portType="ns1:InventoryService"
          operation="undoWithdraInventory"
          inputVariable="undoWithdrawInventory_Input"
          outputVariable="undoWithdrawInventory_Output"/>
      </compensationHandler>
      <invoke name="RemoveInventory"
        partnerLink="InventorySystem"
        portType="ns1:InventoryService"
        operation="withdrawInventory"
        inputVariable="WithdrawInventory_Input"
        outputVariable="WithdrawInventory_Output"/>
      </scope>
      <invoke name="Invoke_StockToInventory"
        partnerLink="InventorySystem"
        portType="ns1:InventoryService"
        operation="stockInventory"
        inputVariable="newStockInventory_Input"
        outputVariable="newStockInventory_Output"/>
  </sequence>
</scope>

Example 19.3 - A compensation routine that invokes an undo operation (highlighted) in the event that the StockToInventory call fails. The catch construct catches the fault condition and then invokes the undoWithdrawInventory operation.