Support for XML constructs

IBM Transformation Extender validation supports the following XML constructs.

Character Data
During validation, character data is mapped by the XML parser to IBM Transformation Extender types. This data includes both parsed character data (PCDATA) and unparsed character data (CDATA).
Comments and Processor Instructions
XML comments and processing instructions (PI) are mapped to floating components in schemas.
The XML Schema importer supports the specification of arbitrary prefixes for namespaces declared in the input grammar.
XSDL Hints
The xsi:schemaLocation and xsi:noNamespaceSchemaLocation attributes are collectively known as XML Schema Definition Language (XSDL) hints. These attributes specify the location of the XML Schema(s) that the XML parser uses for validation.

An XML Schema allows either or both of these attributes to display within any element tag. But the XML parser respects the location values only when the XSDL hint is specified in the root element of the schema.

The Doc group type of schemas that are created with the XML Schema or XML DTD importer contains the location of the Xerces DTD or Xerces XML Schema that is used for Xerces XML validation. The Intent > Validate As > Location property can be modified. However, use the Schema > Type > Metadata card setting in the map to change the location of the DTD or Schema if needed.
Empty Elements
Only one set of initiators and terminators for the Empty element is required for validation.
Nillable Elements
A nillable element can have one of three states: absent, present with content, or present with nil content. Both the DTD and XML Schema allow the definition of optional elements in the instance document. Additionally, the XML Schema allows nillable elements where the content can be empty when it contains an xsi:nil attribute with a value of "true", despite the fact the element's content is mandatory.

The XML Schema Importer can create the content of a nillable element within a group with a range of (0:1), which makes the element content optional.

Mixed Content
When parsing elements with a mixed content model (containing both character data and child elements), the DTD and XML Schema importers generate text items within the mixed content (instead of character sequences).
Regular Expressions
An XML Schema allows the restriction of the values of simple types that are based on regular expressions or pattern facets. During XML validation, the parser enforces the pattern facet. The XML Schema Importer fills the appropriate type properties with pattern facets encountered in the input schema, which are viewable in the Type Designer.