With Saxon-SA, source documents may be validated against a schema. Not only does this perform a check that the document is valid, it also adds type information to each element and attribute node in the document to identify the schema type against which it was validated. It may also expand the source document by adding default values of elements and attributes.
If the option -val:strict is specified on the command line for com.saxonica.Query
or com.saxonica.Transform, then the principal source document to the query or transformation
is schema-validated, as is every document loaded using the doc() or document()
function. Saxon will look among all the loaded schemas for an element declaration that matches the outermost
element of the document, and will then check that the document is valid against that element declaration, reporting
a fatal error if it is not. The loaded schemas include schemas imported statically into the query or stylesheet
using import schema or xsl:import-schema, schemas referenced in the
xsi:schemaLocation or xsi:noNamespaceSchemaLocation attributes of the source
document itself, and schemas loaded by the application using the addSchema method of the
Configuration object.
As an alternative to -val:strict, the option -val:lax may be specified. This validates
the document if and only if an element declaration can be found. If there is no declaration of the outermost
element in any loaded schema, then it is left as an untyped document.
When invoking transformations or queries from the Java API, the equivalent of the -val:strict option
is to call the method setSchemaValidation(Validation.STRICT) on the Configuration
object. The equivalent of -val:lax is setSchemaValidation(Validation.LAX).
When documents are built using the DocumentBuilder in the s9api interface, or in the Saxon.Api
interface on .NET, validation may be controlled by setting the appropriate options on the DocumentBuilder.
On Java interfaces that expect a JAXP Source object it is possible to request validation by supplying
an AugmentedSource. This consists of a Source and a set of options, including
validation options; since AugmentedSource implements the JAXP Source interface
it is possible to use it anywhere that a Source is expected, including as the object returned by
a user-written URIResolver.
Saxon's standard URIResolver uses this technique if it has been enabled
(for example by using -p on the command line). With this option,
any URI containing the query parameter ?val=strict (for example, doc('source.xml?val=strict'))
causes strict validation to be requested
for that document, while ?val=lax requests lax validation,
and ?val=strip requests no validation.
