Working with Predicates

The BPEL Mapper enables you to create a predicate that consists of XPath functions.

A predicate applies a condition to a node that can have multiple values. The result is the subset of nodes that satisfy the condition.

For example, assume that a node represents the number of products. If you want to select all products whose number is greater than 50, then you can use the greater than and number literal functions to define the condition.

Only certain types of nodes allow you to create predicates. The pop-up menu of these nodes contains the New Predicate option. When you expand the tree component in the source tree pane, the nodes that can have predicates are marked with an asterisk (*).

Once you create a predicate, you can use the predicate in an assignment. For example, you can copy data from a predicate in the source tree pane to a node in the destination tree pane.

You can edit or delete an existing predicate.

To create a predicate:

1. In the source tree pane, right-click a node that is marked with an asterisk (*) and choose New Predicate.

   The Predicate Editor appears.

2. Use XPath functions to create the condition for the predicate. Map the result to the predicate node in the destination tree pane.

3. Click OK.

   The editor adds the predicate node immediately below the original node. The condition appears in brackets.

To edit a predicate:

1. In the source tree pane, right-click the predicate node and choose Edit Predicate.

2. Modify the condition.

3. Click OK.

To delete a predicate:

1. In the source tree pane, right-click the predicate node and choose Delete Predicate.

2. Click Yes.