Content validation

Overview

The API Gateway can examine the contents of an XML message to ensure that it meets certain criteria. It uses boolean XPath expressions to evaluate whether or not a specific element or attribute contains a certain value.

For example, you can configure XPath expressions to make sure the value of an element matches a certain string, to check the value of an attribute is greater (or less) than a specific number, or that an element occurs a fixed amount of times within an XML body.

There are two ways to configure XPath expressions in a Content Validation filter:

Manual XPath configuration

To manually configure an XPath expression:

  1. On the Content Validation dialog, click the Add button next to the XPath Expression field. Alternatively, you can select a previously configured XPath expression from the list.
  2. In the XPath Expression dialog, enter a name for the expression in the Name field, and enter the expression in the XPath Expression field.
  3. To resolve any prefixes within the XPath expression, enter the namespace mappings in the table.

For some example XPath expressions, see Configure XPath expressions in the API Gateway Policy Developer Guide.

XPath wizard

The XPath wizard assists you with creating valid XPath expressions. For more information, see Configure XPath expressions in the API Gateway Policy Developer Guide.

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