net.sf.saxon.sxpath

Class XPathEvaluator

public class XPathEvaluator extends Object

This is a cut-down version of the XPathEvaluator in the net.sf.saxon.xpath package. It provides much of the same functionality, but without any dependencies on the JAXP 1.3 interfaces, which are not available in JDK 1.4. The main restrictions are that it does not support mechanisms for defining variables or functions.

Author: Michael H. Kay

Constructor Summary
XPathEvaluator()
Default constructor.
XPathEvaluator(Configuration config)
Construct an XPathEvaluator with a specified configuration.
Method Summary
NodeInfobuild(Source source)
Build a source document.
XPathExpressioncreateExpression(String expression)
Prepare an XPath expression for subsequent evaluation.
ConfigurationgetConfiguration()
Get the Configuration in use
NamespaceResolvergetNamespaceResolver()
Get the external namespace resolver, if one has been set using
IndependentContextgetStaticContext()
Get the current static context.
static voidmain(String[] args)
A simple command-line interface for the XPathEvaluator (not documented).
voidsetNamespaceResolver(NamespaceResolver namespaceContext)
Set the external namespace resolver to be used.
voidsetStaticContext(IndependentContext context)
Set the static context for compiling XPath expressions.
voidsetStripSpace(boolean strip)
Indicate whether all whitespace text nodes in the source document are to be removed.

Constructor Detail

XPathEvaluator

public XPathEvaluator()
Default constructor. Creates an XPathEvaluator with a default configuration and name pool.

XPathEvaluator

public XPathEvaluator(Configuration config)
Construct an XPathEvaluator with a specified configuration.

Parameters: config the configuration to be used

Method Detail

build

public NodeInfo build(Source source)
Build a source document.

Parameters: source a JAXP Source object. This may be any implementation of Source that Saxon recognizes: not only the standard kinds of source such as StreamSource, SAXSource, and DOMSource, but also for example a JDOM or XOM DocumentWrapper.

Returns: the NodeInfo representing the root of the constructed tree.

Throws: XPathException if, for example, XML parsing fails.

createExpression

public XPathExpression createExpression(String expression)
Prepare an XPath expression for subsequent evaluation.

Parameters: expression The XPath expression to be evaluated, 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.

getConfiguration

public Configuration getConfiguration()
Get the Configuration in use

getNamespaceResolver

public NamespaceResolver getNamespaceResolver()
Get the external namespace resolver, if one has been set using XPathEvaluator

Returns: the namespace context if set, or null otherwise

getStaticContext

public IndependentContext getStaticContext()
Get the current static context. This will always return a value; if no static context has been supplied by the user, the system creates its own.

main

public static void main(String[] args)
A simple command-line interface for the XPathEvaluator (not documented). First parameter is the filename containing the source document, second parameter is the XPath expression.

setNamespaceResolver

public void setNamespaceResolver(NamespaceResolver namespaceContext)
Set the external namespace resolver to be used. This overrides any namespaces declared directly using declareNamespace on the staticContext object

Parameters: namespaceContext The namespace context

setStaticContext

public void setStaticContext(IndependentContext context)
Set the static context for compiling XPath expressions. This provides 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.

setStripSpace

public void setStripSpace(boolean strip)
Indicate whether all whitespace text nodes in the source document are to be removed.

Parameters: strip True if all whitespace text nodes are to be stripped from the source document, false otherwise. The default if the method is not called is false.