Class UseWhenFilter

All Implemented Interfaces:
Result, Receiver

public class UseWhenFilter extends ProxyReceiver
This is a filter inserted into the input pipeline for processing stylesheet modules, whose task is to evaluate use-when expressions and discard those parts of the stylesheet module for which the use-when attribute evaluates to false.

Originally, with XSLT 2.0, this class did use-when filtering and very little else. In XSLT 3.0 its role has expanded: it evaluates shadow attributes and static variables, and collects information about package dependencies.

  • Constructor Details

    • UseWhenFilter

      public UseWhenFilter(Compilation compilation, Receiver next, NestedIntegerValue precedence)
      Create a UseWhenFilter
      Parameters:
      compilation - the compilation episode
      next - the next receiver in the pipeline
      precedence - the import precedence expressed as a dotted-decimal integer, e.g. 1.4.6
  • Method Details

    • open

      public void open() throws XPathException
      Start of document
      Specified by:
      open in interface Receiver
      Overrides:
      open in class ProxyReceiver
      Throws:
      XPathException - if an error occurs
    • startElement

      public void startElement(NodeName elemName, SchemaType type, AttributeMap attributes, NamespaceMap namespaces, Location location, int properties) throws XPathException
      Notify the start of an element.
      Specified by:
      startElement in interface Receiver
      Overrides:
      startElement in class ProxyReceiver
      Parameters:
      elemName - the name of the element.
      type - the type annotation of the element.
      attributes - the attributes of this element
      namespaces - the in-scope namespaces of this element: generally this is all the in-scope namespaces, without relying on inheriting namespaces from parent elements
      location - an object providing information about the module, line, and column where the node originated
      properties - bit-significant properties of the element node. If there are no relevant properties, zero is supplied. The definitions of the bits are in class ReceiverOption
      Throws:
      XPathException - if an error occurs
    • endElement

      public void endElement() throws XPathException
      End of element
      Specified by:
      endElement in interface Receiver
      Overrides:
      endElement in class ProxyReceiver
      Throws:
      XPathException - if an error occurs
    • characters

      public void characters(UnicodeString chars, Location locationId, int properties) throws XPathException
      Character data
      Specified by:
      characters in interface Receiver
      Overrides:
      characters in class ProxyReceiver
      Parameters:
      chars - The characters
      locationId - provides information such as line number and system ID.
      properties - Bit significant value. The following bits are defined:
      DISABLE_ESCAPING
      Disable escaping for this text node
      USE_CDATA
      Output as a CDATA section
      Throws:
      XPathException - if an error occurs
    • processingInstruction

      public void processingInstruction(String target, UnicodeString data, Location locationId, int properties)
      Processing Instruction
      Specified by:
      processingInstruction in interface Receiver
      Overrides:
      processingInstruction in class ProxyReceiver
      Parameters:
      target - The PI name. This must be a legal name (it will not be checked).
      data - The data portion of the processing instruction
      locationId - provides information such as line number and system ID.
      properties - Additional information about the PI.
    • comment

      public void comment(UnicodeString chars, Location locationId, int properties) throws XPathException
      Output a comment
      Specified by:
      comment in interface Receiver
      Overrides:
      comment in class ProxyReceiver
      Parameters:
      chars - The content of the comment
      locationId - provides information such as line number and system ID.
      properties - Additional information about the comment.
      Throws:
      XPathException - if an error occurs
    • evaluateStatic

      public Sequence evaluateStatic(String expression, Location locationId, UseWhenStaticContext staticContext) throws XPathException
      Evaluate a static expression (to initialize a static variable)
      Parameters:
      expression - the expression to be evaluated
      locationId - identifies the location of the expression in case error need to be reported
      staticContext - the static context for evaluation of the expression
      Returns:
      the effective boolean value of the result of evaluating the expression
      Throws:
      XPathException - if evaluation of the expression fails