Configuration Guides › Policy Server Configuration Guide › Variables › Create a Variable › Create an XML Body Variable

Create an XML Body Variable

XML Body variables let you obtain information from any element in the body (or payload) of an incoming XML message for use in policy expressions and responses.

Specifically, XML Body variables are resolved to the value of an XPath string that identifies an element (and optionally, an operation to perform on that element) of an XML document.

Note: For more information about XPATH, see the XPATH specification available at http://www.w3.org/TR/xpath.

To create a variable

1. Open the domain to which to you want to add a variable.
2. Click the Variables tab.

   A table lists the variables associated with the domain.

3. Click Create Variable.

   The Create Variable screen appears.

4. Verify that Create a new object is selected, and click OK.

   Variable settings open.

5. Type the variable name in the Name field.
6. Select XML Body from the Variable Type list.
7. XML Body variable settings open.

   Note: Click Help for descriptions of settings and controls, including their respective requirements and limits.

8. Enter information in the following fields:

   Description

   (Optional) Specifies a brief description of the variable.

   Limits: No more than 1KB.

   Return Type

   Specifies the data type in which the value of the specified XPATH query should be returned:

   • Boolean
   • Date
   • Number
   • String (the default)

9. Do one of the following:
   • Load a schema (.xsd) file and select the element to map to the specified field name by browsing using the following procedure:
     1. Click Browse and navigate to the schema file.
     2. Click Upload XSD File.

        The schema is uploaded.

     3. Select the schema element that you want to map to the specified field name in the Select a node group box.

        The Select a node group box displays the selected schema using a standard tree-style hierarchical view. Click the plus sign (+) next to an element to expand it. Click the minus sign (-) beside an expanded element to contract it. Elements marked with an asterisk (*) are repeatable within the XML document (that is, incoming XML documents may contain multiple instances of that element).

   • Unset the Advance XPath query option and type an XPATH query defining the mapping in the XPath field.
10. Optionally, if you are working from a loaded schema in the Select a node group box, specify an XPath function (count, div, index, mod, sum) that you want to apply to a repeatable schema element, by choosing it from the Function drop-down list.

    The Function option lets you create more complex mappings by processing functions that further evaluate the XML document.

    Note: For more information about these functions, go to the XPATH specification at http://www.w3.org/TR/xpath.

11. Click Finish.

    The variable appears in the Variables tab of the domain. The variable can now be used in policy expressions or responses.