Let us now implement the same scenario using the <forEach> loop:
- We don't want to overwrite the
<while>loop example; therefore, we will add another BPEL process component to the composite diagram. We will call itBookOrderForEachBPEL:
- We will also wire it with
BookWarehousingBPEL:
- We will use exactly the same schema as in the previous example. To implement the BPEL process, we will first add the
<forEach>activity to the process flow by dragging-and-dropping For Each from the Components palette (you will find it under Structured Activities):
- We will double-click the
ForEach1activity and set Name asManageOrdersand name of the counter variable (Counter name) asOrderCounter:
- In the Counter Values tab, we will set the start and the end value for the counter. The start value is
1and the end value is thecount($inputVariable.payload/ns1:BookData)expression. With this expression, we will count the number of books in the array. This is exactly the number of times we wish the<forEach>loop to repeat:
- You can now click the OK button. As in the previous example, within the
<forEach>loop, we will extract the book order item from the array, and prepare the request for theBookWarehousingBPELprocess and invoke it. We do not need to manually increase the counter however. - Let us first add the
<invoke>activity. We will name the activityInvokeBookWarehousing. We will also create two global variables on the fly,BookWarehousingRequestandBookWarehousingResponse:
- Next, we will add the
<assign>activity to prepare the request. We will add the<assign>activity before the<invoke>activity and set the following copy expression:
As you can see, we will copy the
$inputVariable.payload/ns1:BookData[$OrderCounter]order item to the$BookWarehousingRequest.payload/ns1:BookDataelement.
We have successfully developed the BookOrderForEach BPEL process, which iterates through book data items using a <forEach> loop.
The process flow should look like this:
We can see that the <forEach> loop is a little simpler, as we do not have to take care of the counter variable manually.
The source code should read as follows:
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