XPathEvaluator. In a DOM implementation which supports the
* XPath 3.0 feature, as described above, the XPathEvaluator
* interface will be implemented on the same object which implements the
* Document interface permitting it to be obtained by the usual
* binding-specific method such as casting or by using the DOM Level 3
* getInterface method. In this case the implementation obtained from the
* Document supports the XPath DOM module and is compatible with the XPath
* 1.0 specification.
* Evaluation of expressions with specialized extension functions or
* variables may not work in all implementations and is, therefore, not
* portable. XPathEvaluator implementations may be available
* from other sources that could provide specific support for specialized
* extension functions or variables as would be defined by other
* specifications.
*
See also the Document Object Model (DOM) Level 3 XPath Specification.
*/
public interface XPathEvaluator {
/**
* Creates a parsed XPath expression with resolved namespaces. This is
* useful when an expression will be reused in an application since it
* makes it possible to compile the expression string into a more
* efficient internal form and preresolve all namespace prefixes which
* occur within the expression.
* @param expression The XPath expression string to be parsed.
* @param resolver The resolver permits translation of
* prefixes within the XPath expression into appropriate namespace URIs
* . If this is specified as null, any namespace prefix
* within the expression will result in DOMException
* being thrown with the code NAMESPACE_ERR.
* @return The compiled form of the XPath expression.
* @exception XPathException
* INVALID_EXPRESSION_ERR: Raised if the expression is not legal
* according to the rules of the XPathEvaluatori
* @exception DOMException
* NAMESPACE_ERR: Raised if the expression contains namespace prefixes
* which cannot be resolved by the specified
* XPathNSResolver.
*/
public XPathExpression createExpression(String expression,
XPathNSResolver resolver)
throws XPathException, DOMException;
/**
* Adapts any DOM node to resolve namespaces so that an XPath expression
* can be easily evaluated relative to the context of the node where it
* appeared within the document. This adapter works like the DOM Level 3
* method lookupNamespaceURI on nodes in resolving the
* namespaceURI from a given prefix using the current information
* available in the node's hierarchy at the time lookupNamespaceURI is
* called. also correctly resolving the implicit xml prefix.
* @param nodeResolver The node to be used as a context for namespace
* resolution.
* @return XPathNSResolver which resolves namespaces with
* respect to the definitions in scope for a specified node.
*/
public XPathNSResolver createNSResolver(Node nodeResolver);
/**
* Evaluates an XPath expression string and returns a result of the
* specified type if possible.
* @param expression The XPath expression string to be parsed and
* evaluated.
* @param contextNode The context is context node for the
* evaluation of this XPath expression. If the XPathEvaluator was
* obtained by casting the Document then this must be
* owned by the same document and must be a Document,
* Element, Attribute, Text,
* CDATASection, Comment,
* ProcessingInstruction, or XPathNamespace
* node. If the context node is a Text or a
* CDATASection, then the context is interpreted as the
* whole logical text node as seen by XPath, unless the node is empty
* in which case it may not serve as the XPath context.
* @param resolver The resolver permits translation of
* prefixes within the XPath expression into appropriate namespace URIs
* . If this is specified as null, any namespace prefix
* within the expression will result in DOMException
* being thrown with the code NAMESPACE_ERR.
* @param type If a specific type is specified, then the
* result will be returned as the corresponding type.For XPath 1.0
* results, this must be one of the codes of the
* XPathResult interface.
* @param result The result specifies a specific result
* object which may be reused and returned by this method. If this is
* specified as nullor the implementation does not reuse
* the specified result, a new result object will be constructed and
* returned.For XPath 1.0 results, this object will be of type
* XPathResult.
* @return The result of the evaluation of the XPath expression.For XPath
* 1.0 results, this object will be of type XPathResult.
* @exception XPathException
* INVALID_EXPRESSION_ERR: Raised if the expression is not legal
* according to the rules of the XPathEvaluatori
*
TYPE_ERR: Raised if the result cannot be converted to return the
* specified type.
* @exception DOMException
* NAMESPACE_ERR: Raised if the expression contains namespace prefixes
* which cannot be resolved by the specified
* XPathNSResolver.
*
WRONG_DOCUMENT_ERR: The Node is from a document that is not
* supported by this XPathEvaluator.
*
NOT_SUPPORTED_ERR: The Node is not a type permitted as an XPath
* context node or the request type is not permitted by this
* XPathEvaluator.
*/
public Object evaluate(String expression,
Node contextNode,
XPathNSResolver resolver,
short type,
Object result)
throws XPathException, DOMException;
}