The Validate action validates the contents of a section of the FactBase against a W3C Schema.
The first parameter indicates the XSD to validate against. The XSD file can either be specified directly (schema), or can be given as an XPath into the FactBase that will provide the XSD filename at runtime (XPath to schema).
The second parameter specifies the validation start point, and so allows the user to only validate portions of a document. This may be useful when data is contained within some sort of message envelope, for example. The final parameter specifies the location to insert validation messages. As the validator runs it may generate errors, and these will be inserted in XML form to the specified location. The format of these errors is: <error id="" col="" line="" desc="" />.
