# Using the Data Palette of the Mapper

The Data Palette of the mapper provides a location to access the variables and their subelements. You can drag-and-drop variables or their subelements from the Data Palette of the mapper into the Constraints and Target Expression tabs of the mapper.

Note: You can also drag-and-drop elements from the Source pane of the mapper directly into the Constraints and Target Expression tabs of the mapper.

The following types of variables are displayed in the Data Palette of the mapper:

- Source—The variables listed in Source section of the Data Palette are the source (input) types selected for the transformation in the Configure XQuery Transformation Method pane. To learn more, see Selecting Source and Target Types.
- Structural Link—When a structural link is selected in the Design View of an XQ file, the Structural Link section of the Data Palette lists the loop iteration variable associated with the XQuery for loop generated by the structural link. This variable is in scope for all subelements of the node with the structural link.

When you create link(s) between a source repeating element and a target repeating element, a structural link between the two elements is created and a XQuery for loop is generated. When you use the Constraints tab to limit or constrain repeating element(s), a where clause is added to the XQuery for loop. To learn more about which features of the mapper functionality to use to manipulate and constrain data, see Examples: Manipulating and Constraining Data Using XQuery.

Caution: The Data Palette of the mapper displays a different set of variables than the variables displayed in the Data Palette for business processes (JPDs). The variables displayed in the Data Palette of the mapper are used only in transformations and are distinct from the variables used in business processes.

To View the Variables Associated with Transformation in the Data Palette

1. For the Data Palette of the mapper to be visible, the Design View of an XQ file must be selected.

To view an XQ file in the Design View:

1. If the Application tab is not visible in WebLogic Workshop, from the menu bar choose View —> Application.
2. In the Application tab, double-click XQ file and select the Design View tab.

2. (Optional) Select a structural link to view the repeating element(s) associated with the current link that can be constrained using Constraints tab.
3. If the Data Palette is not visible in WebLogic Workshop, from the menu bar choose View —> Windows —> Application.

Related Topics

Modifying Links Using the Target Expression Tab

Examples: Manipulating and Constraining Data Using XQuery

Adding If-Then-Else Constructs to a Link

Business Process Variables and Data Types