Class SystemProperty

All Implemented Interfaces:
Serializable, SourceLocator, LocationProvider, SaxonLocator, CallableExpression, InstructionInfo, Locator

public class SystemProperty extends SystemFunction implements CallableExpression
Implementation of the XSLT system-property() function
See Also:
  • Constructor Details

    • SystemProperty

      public SystemProperty()
  • Method Details

    • checkArguments

      public void checkArguments(ExpressionVisitor visitor) throws XPathException
      Description copied from class: SystemFunction
      Method called during static type checking
      Overrides:
      checkArguments in class SystemFunction
      Parameters:
      visitor - the expression visitor
      Throws:
      XPathException - if the arguments are incorrect
    • preEvaluate

      public Expression preEvaluate(ExpressionVisitor visitor) throws XPathException
      preEvaluate: this method performs compile-time evaluation for properties in the XSLT namespace only
      Overrides:
      preEvaluate in class FunctionCall
      Parameters:
      visitor - an expression visitor
      Returns:
      the result of the early evaluation, or the original expression, or potentially a simplified expression
      Throws:
      XPathException - if evaluation fails
    • evaluateItem

      public Item evaluateItem(XPathContext context) throws XPathException
      Evaluate the function at run-time
      Overrides:
      evaluateItem in class Expression
      Parameters:
      context - The context in which the expression is to be evaluated
      Returns:
      the node or atomic value that results from evaluating the expression; or null to indicate that the result is an empty sequence
      Throws:
      XPathException - if any dynamic error occurs evaluating the expression
    • call

      public SequenceIterator call(SequenceIterator[] arguments, XPathContext context) throws XPathException
      Evaluate the expression
      Specified by:
      call in interface CallableExpression
      Parameters:
      arguments - the values of the arguments, supplied as SequenceIterators
      context - the dynamic evaluation context
      Returns:
      the result of the evaluation, in the form of a SequenceIterator
      Throws:
      XPathException - if a dynamic error occurs during the evaluation of the expression
    • getProperty

      public static String getProperty(String uri, String local, Configuration config)
      Here's the real code:
      Parameters:
      uri - the namespace URI of the system property name
      local - the local part of the system property name
      config - the Saxon configuration
      Returns:
      the value of the corresponding system property