What Happens When You Create a While Activity

The code that follows provides an example of the .bpel file after design completion. The while activity includes a scope activity. The scope activity includes sequence and fault handlers at the top level. The sequence includes invoke and assign activities and fault handlers that define a catchAll containing assign and wait activities wrapped in a sequence.

The following code calls an external service. If the external service throws a fault, the fault handler catches the fault and increments the dbStatus variable value.

Therefore, the exit condition of the while loop is either of the following:

• There is no exception, upon which the dbStatus value is set to a value of 10, which results in the while condition evaluating to false.

• After throwing a fault five times, the dbStatus value is 5, and the while condition returns false.

<while name="While_1" condition="bpws:getVariableData('dbStatus') > 5">
      <scope name="Scope_1">
<faultHandlers>
          <catchAll>
            <sequence name="Sequence_2">
              <assign name="assign_DB_retry">
                <copy>
                  <from expression="bpws:getVariableData('dbStatus') + 1"/>
                  <to variable="dbStatus"/>
                </copy>
              </assign>
              <wait name="Wait_30_sec" for="'PT31S'"/>
            </sequence>
          </catchAll>
        </faultHandlers>
        <sequence name="Sequence_1">
          <invoke name="Write_DBWrite" partnerLink="WriteDBRecord"
                  portType="ns2:WriteDBRecord_ptt" operation="insert"
                  inputVariable="Invoke_DBWrite_merge_InputVariable"/>
          <assign name="Assign_dbComplete">
            <copy>
              <from expression="'10'"/>
              <to variable="dbStatus"/>
            </copy>
          </assign>
        </sequence>
      </scope>
    </while>

Note:

The while activity code fragment in the preceding example uses a BPEL 1.1 construct of bpws:getVariableData('dbStatus'). For BPEL 2.0, variables are referenced directly using $ sign and dot (.) notation. For example:

<while name="While1">
   <condition>$inputVariable.payload/client:counter > 0
   </condition>