Package org.apache.xml.security.utils

Class XPathFuncHereAPI

java.lang.Object

org.apache.xml.security.utils.XPathFuncHereAPI

public class XPathFuncHereAPI
extends java.lang.Object

This class does the same as XPathAPI except that the XPath strings are not supplied as Strings but as Text, Attribute or {ProcessingInstruction} nodes which contain the XPath string. This enables us to use the here() function.
The methods in this class are convenience methods into the low-level XPath API. These functions tend to be a little slow, since a number of objects must be created for each evaluation. A faster way is to precompile the XPaths using the low-level API, and then just use the XPaths over and over.

Author:

$Author$

See Also:

XPath Specification

Constructor Summary

Constructors

Constructor	Description
XPathFuncHereAPI()

Method Summary

Modifier and Type	Method	Description
static org.apache.xpath.objects.XObject	eval(org.w3c.dom.Node contextNode, org.w3c.dom.Node xpathnode)	Evaluate XPath string to an XObject.
static org.apache.xpath.objects.XObject	eval(org.w3c.dom.Node contextNode, org.w3c.dom.Node xpathnode, org.apache.xml.utils.PrefixResolver prefixResolver)	Evaluate XPath string to an XObject.
static org.apache.xpath.objects.XObject	eval(org.w3c.dom.Node contextNode, org.w3c.dom.Node xpathnode, org.w3c.dom.Node namespaceNode)	Evaluate XPath string to an XObject.
static org.w3c.dom.traversal.NodeIterator	selectNodeIterator(org.w3c.dom.Node contextNode, org.w3c.dom.Node xpathnode)	Use an XPath string to select a nodelist.
static org.w3c.dom.traversal.NodeIterator	selectNodeIterator(org.w3c.dom.Node contextNode, org.w3c.dom.Node xpathnode, org.w3c.dom.Node namespaceNode)	Use an XPath string to select a nodelist.
static org.w3c.dom.NodeList	selectNodeList(org.w3c.dom.Node contextNode, org.w3c.dom.Node xpathnode)	Use an XPath string to select a nodelist.
static org.w3c.dom.NodeList	selectNodeList(org.w3c.dom.Node contextNode, org.w3c.dom.Node xpathnode, org.w3c.dom.Node namespaceNode)	Use an XPath string to select a nodelist.
static org.w3c.dom.Node	selectSingleNode(org.w3c.dom.Node contextNode, org.w3c.dom.Node xpathnode)	Use an XPath string to select a single node.
static org.w3c.dom.Node	selectSingleNode(org.w3c.dom.Node contextNode, org.w3c.dom.Node xpathnode, org.w3c.dom.Node namespaceNode)	Use an XPath string to select a single node.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

XPathFuncHereAPI

public XPathFuncHereAPI()

Method Detail

selectSingleNode

public static org.w3c.dom.Node selectSingleNode(org.w3c.dom.Node contextNode,
                                                org.w3c.dom.Node xpathnode)
                                         throws javax.xml.transform.TransformerException

Use an XPath string to select a single node. XPath namespace prefixes are resolved from the context node, which may not be what you want (see the next method).

Parameters:

contextNode - The node to start searching from.

xpathnode - A Node containing a valid XPath string.

Returns:

The first node found that matches the XPath, or null.

Throws:

javax.xml.transform.TransformerException

selectSingleNode

public static org.w3c.dom.Node selectSingleNode(org.w3c.dom.Node contextNode,
                                                org.w3c.dom.Node xpathnode,
                                                org.w3c.dom.Node namespaceNode)
                                         throws javax.xml.transform.TransformerException

Use an XPath string to select a single node. XPath namespace prefixes are resolved from the namespaceNode.

Parameters:

contextNode - The node to start searching from.

xpathnode -

namespaceNode - The node from which prefixes in the XPath will be resolved to namespaces.

Returns:

The first node found that matches the XPath, or null.

Throws:

javax.xml.transform.TransformerException

selectNodeIterator

public static org.w3c.dom.traversal.NodeIterator selectNodeIterator(org.w3c.dom.Node contextNode,
                                                                    org.w3c.dom.Node xpathnode)
                                                             throws javax.xml.transform.TransformerException

Use an XPath string to select a nodelist. XPath namespace prefixes are resolved from the contextNode.

Parameters:

contextNode - The node to start searching from.

xpathnode -

Returns:

A NodeIterator, should never be null.

Throws:

javax.xml.transform.TransformerException

selectNodeIterator

public static org.w3c.dom.traversal.NodeIterator selectNodeIterator(org.w3c.dom.Node contextNode,
                                                                    org.w3c.dom.Node xpathnode,
                                                                    org.w3c.dom.Node namespaceNode)
                                                             throws javax.xml.transform.TransformerException

Use an XPath string to select a nodelist. XPath namespace prefixes are resolved from the namespaceNode.

Parameters:

contextNode - The node to start searching from.

xpathnode -

namespaceNode - The node from which prefixes in the XPath will be resolved to namespaces.

Returns:

A NodeIterator, should never be null.

Throws:

javax.xml.transform.TransformerException

selectNodeList

public static org.w3c.dom.NodeList selectNodeList(org.w3c.dom.Node contextNode,
                                                  org.w3c.dom.Node xpathnode)
                                           throws javax.xml.transform.TransformerException

Use an XPath string to select a nodelist. XPath namespace prefixes are resolved from the contextNode.

Parameters:

contextNode - The node to start searching from.

xpathnode -

Returns:

A NodeIterator, should never be null.

Throws:

javax.xml.transform.TransformerException

selectNodeList

public static org.w3c.dom.NodeList selectNodeList(org.w3c.dom.Node contextNode,
                                                  org.w3c.dom.Node xpathnode,
                                                  org.w3c.dom.Node namespaceNode)
                                           throws javax.xml.transform.TransformerException

Use an XPath string to select a nodelist. XPath namespace prefixes are resolved from the namespaceNode.

Parameters:

contextNode - The node to start searching from.

xpathnode -

namespaceNode - The node from which prefixes in the XPath will be resolved to namespaces.

Returns:

A NodeIterator, should never be null.

Throws:

javax.xml.transform.TransformerException

eval

public static org.apache.xpath.objects.XObject eval(org.w3c.dom.Node contextNode,
                                                    org.w3c.dom.Node xpathnode)
                                             throws javax.xml.transform.TransformerException

Evaluate XPath string to an XObject. Using this method, XPath namespace prefixes will be resolved from the namespaceNode.

Parameters:

contextNode - The node to start searching from.

xpathnode -

Returns:

An XObject, which can be used to obtain a string, number, nodelist, etc, should never be null.

Throws:

javax.xml.transform.TransformerException

See Also:

XObject, XNull, XBoolean, XNumber, XString, XRTreeFrag

eval

public static org.apache.xpath.objects.XObject eval(org.w3c.dom.Node contextNode,
                                                    org.w3c.dom.Node xpathnode,
                                                    org.w3c.dom.Node namespaceNode)
                                             throws javax.xml.transform.TransformerException

Evaluate XPath string to an XObject. XPath namespace prefixes are resolved from the namespaceNode. The implementation of this is a little slow, since it creates a number of objects each time it is called. This could be optimized to keep the same objects around, but then thread-safety issues would arise.

Parameters:

contextNode - The node to start searching from.

xpathnode -

namespaceNode - The node from which prefixes in the XPath will be resolved to namespaces.

Returns:

An XObject, which can be used to obtain a string, number, nodelist, etc, should never be null.

Throws:

javax.xml.transform.TransformerException

See Also:

XObject, XNull, XBoolean, XNumber, XString, XRTreeFrag

eval

public static org.apache.xpath.objects.XObject eval(org.w3c.dom.Node contextNode,
                                                    org.w3c.dom.Node xpathnode,
                                                    org.apache.xml.utils.PrefixResolver prefixResolver)
                                             throws javax.xml.transform.TransformerException

Evaluate XPath string to an XObject. XPath namespace prefixes are resolved from the namespaceNode. The implementation of this is a little slow, since it creates a number of objects each time it is called. This could be optimized to keep the same objects around, but then thread-safety issues would arise.

Parameters:

contextNode - The node to start searching from.

xpathnode -

prefixResolver - Will be called if the parser encounters namespace prefixes, to resolve the prefixes to URLs.

Returns:

An XObject, which can be used to obtain a string, number, nodelist, etc, should never be null.

Throws:

javax.xml.transform.TransformerException

See Also:

XObject, XNull, XBoolean, XNumber, XString, XRTreeFrag