Package net.sf.saxon.sxpath

Class XPathEvaluator

java.lang.Object
net.sf.saxon.sxpath.XPathEvaluator
Direct Known Subclasses:
XSDAssert.CustomizedXPath
public class XPathEvaluator extends Object
This class provides a native Saxon API for free-standing evaluation of XPath expressions. This is the primitive XPath interface used internally within Saxon.

The preferred API for user applications calling XPath is the s9api XPathCompiler interface.

Since:
8.4

  • Constructor Details

    • XPathEvaluator

      public XPathEvaluator(Configuration config)
      Construct an XPathEvaluator with a specified configuration.
      Parameters:
      config - the configuration to be used. If the XPathEvaluator is to be used to run schema-aware XPath expressions this must be an instance of EnterpriseConfiguration

  • Method Details

    • getConfiguration

      public Configuration getConfiguration()
      Get the Configuration in use.
      Returns:
      the Saxon configuration

    • setStaticContext

      public void setStaticContext(XPathStaticContext context)
      Set the static context for compiling XPath expressions. This provides more detailed control over the environment in which the expression is compiled, for example it allows namespace prefixes to be declared, variables to be bound and functions to be defined. For most purposes, the static context can be defined by providing and tailoring an instance of the IndependentContext class. Until this method is called, a default static context is used, in which no namespaces are defined other than the standard ones (xml, xslt, and saxon), and no variables or functions (other than the core XPath functions) are available.
      Parameters:
      context - the XPath static context

      Setting a new static context clears any variables and namespaces that have previously been declared.

    • getStaticContext

      public XPathStaticContext getStaticContext()
      Get the current static context. This will always return a value; if no static context has been supplied by the user, the system will have created its own. A system-created static context will always be an instance of IndependentContext
      Returns:
      the static context object

    • createExpression

      public XPathExpression createExpression(String expression) throws XPathException
      Prepare (compile) an XPath expression for subsequent evaluation.
      Parameters:
      expression - The XPath expression to be compiled, supplied as a string.
      Returns:
      an XPathExpression object representing the prepared expression
      Throws:
      XPathException - if the syntax of the expression is wrong, or if it references namespaces, variables, or functions that have not been declared.

    • postProcess

      protected Expression postProcess(Expression exp, ExpressionVisitor visitor, ContextItemStaticInfo cit) throws XPathException
      Customize the expression post-optimization. This method does nothing, but can be overridden in a subclass
      Parameters:
      exp - the expression after optimization
      visitor - an expression visitor that includes static context information
      cit - information about the context item type
      Throws:
      XPathException

    • createPattern

      public XPathExpression createPattern(String pattern) throws XPathException
      Prepare (compile) an XSLT pattern for subsequent evaluation. The result is an XPathExpression object representing a (pseudo-) expression that when evaluated returns a boolean result: true if the context node matches the pattern, false if it does not.
      Parameters:
      pattern - the XSLT pattern to be compiled, supplied as a string
      Returns:
      an XPathExpression object representing the pattern, wrapped as an expression
      Throws:
      XPathException - if the syntax of the expression is wrong, or if it references namespaces, variables, or functions that have not been declared.
      Since:
      9.1