1. Developing SOA Applications with Oracle SOA Suite
  2. Sharing Functionality Across Service Components
  3. Creating Transformations with the XSLT Map Editor
  4. Using Template Rules
  5. How to Refactor an Existing Map to Create a Template Rule

How to Refactor an Existing Map to Create a Template Rule

You can refactor code from an existing template to create a new template rule. This is useful if the template rule that is created can be reused in multiple places, as was the case with the Address template rule created in the previous section.

The Create in Template option enables you to refactor a section of XSLT instructions into a separate template that can be invoked from multiple places.

In the following example, we refactor an existing mapping to create a template rule.

In the following map, the XSLT that processes each Address element in the source is repeated for each Address node. For easier maintenance, you may want to consolidate redundant code into reusable templates. This way, if the code is later updated, you would not have to update multiple copies.

Description of xslt_ex_map.gif follows
Description of the illustration xslt_ex_map.gif

In the preceding map, if the XPath concat expression that creates Street from Street1 and Street2 needs to be modified, there are two copies that would have to be modified. However, if the concat function exists in a single template that is reused to produce both Address elements, then only one concat statement needs to be modified in future.

In the following steps, we refactor the existing mapping to create a single template that processes the Address elements:

  1. Make sure that you are in the XSLT View. You can click XSLT in the top right corner of the XSLT Map Editor to switch to the XSLT View.
  2. Right-click the ShippedTo/Address element in the XSLT pane and select Create in Template from the context menu that appears.
    Description of xslt_creat_in_temp.gif follows
    Description of the illustration xslt_creat_in_temp.gif

    The New Template Rule dialog appears.

    Description of xslt_new_temp_rule2.gif follows
    Description of the illustration xslt_new_temp_rule2.gif

    The Match Node is pre-populated with a suggested match pattern derived from XPath expressions contained under the selected node in the XSLT pane. The elements selected in the target schema tree are the Address node and its children. These elements would be moved to a new template rule.

  3. Click OK.

    A new template rule is created and an apply-templates statement is inserted in place of the Address node. The XPath expressions defined for the elements under the Address node in the XSLT pane are updated to contain relative paths to the Address node (context node) for the new template.

    Description of xslt_map_sample.gif follows
    Description of the illustration xslt_map_sample.gif

    Next, we use this template for both the ShipTo and BillTo Address elements.

  4. Double-click the new template node. The Set Attributes dialog appears.
  5. Under Enter Pattern, enter Address.
  6. Click OK.
  7. Delete the BilledTo/Address element in the XSLT pane.
  8. Right-click the BilledTo node and select Add Child > XSL > apply-templates. This creates an xsl:apply-templates statement in place of the Address node.
  9. Drag a line from the BillTo/Address node in the source pane to the new BilledTo/apply-templates node in the XSLT pane.
    Description of xslt_map_sample2.gif follows
    Description of the illustration xslt_map_sample2.gif

    Both BilledTo and ShippedTo Address elements are now created using a single template rule.