| java.lang.Object net.sf.saxon.sxpath.XPathExpression
XPathExpression | public class XPathExpression (Code) | | This class is a representation of an XPath Expression for use with the XPathEvaluator class.
It is modelled on the XPath API defined in JAXP 1.3, but is cut down to remove any dependencies on JAXP 1.3,
making it suitable for use on vanilla JDK 1.4 installations.
author: Michael H. Kay |
Method Summary | |
public List | evaluate(Source source) Execute a prepared XPath expression, returning the results as a List.
Parameters: source - the document or other node against which the XPath expressionwill be evaluated. | public Object | evaluateSingle(Source source) Execute a prepared XPath expression, returning the first item in the result.
This is useful where it is known that the expression will only return
a singleton value (for example, a single node, or a boolean).
Parameters: source - the document or other node against which the XPath expressionwill be evaluated. | public Expression | getInternalExpression() Low-level method to get the internal Saxon expression object. | public SequenceIterator | rawIterator(Source source) Get a raw iterator over the results of the expression. | protected void | setStackFrameMap(SlotManager map) |
XPathExpression | protected XPathExpression(XPathEvaluator evaluator, Expression exp)(Code) | | The constructor is protected, to ensure that instances can only be
created using the createExpression() method of XPathEvaluator
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evaluate | public List evaluate(Source source) throws XPathException(Code) | | Execute a prepared XPath expression, returning the results as a List.
Parameters: source - the document or other node against which the XPath expressionwill be evaluated. This may be a Saxon NodeInfo object, representing a node in anexisting tree, or it may be any kind of JAXP Source object such as a StreamSourceSAXSource or DOMSource. The results of the expression, as a List. The List represents the sequenceof items returned by the expression. Each item in the list will either be an instanceof net.sf.saxon.om.NodeInfo, representing a node, or a Java object representing an atomic value. |
evaluateSingle | public Object evaluateSingle(Source source) throws XPathException(Code) | | Execute a prepared XPath expression, returning the first item in the result.
This is useful where it is known that the expression will only return
a singleton value (for example, a single node, or a boolean).
Parameters: source - the document or other node against which the XPath expressionwill be evaluated. This may be a Saxon NodeInfo object, representing a node in anexisting tree, or it may be any kind of JAXP Source object such as a StreamSourceSAXSource or DOMSource. The first item in the sequence returned by the expression. If the expressionreturns an empty sequence, this method returns null. Otherwise, it returns the firstitem in the result sequence, represented as a Java object using the same mapping as forthe evaluate() method |
getInternalExpression | public Expression getInternalExpression()(Code) | | Low-level method to get the internal Saxon expression object. This exposes a wide range of
internal methods that may be needed by specialized applications, and allows greater control
over the dynamic context for evaluating the expression.
the underlying Saxon expression object. |
rawIterator | public SequenceIterator rawIterator(Source source) throws XPathException(Code) | | Get a raw iterator over the results of the expression. This returns results without
any conversion of the returned items to "native" Java classes. This method is intended
for use by applications that need to process the results of the expression using
internal Saxon interfaces.
Parameters: source - the document or other node against which the XPath expressionwill be evaluated. This may be a Saxon NodeInfo object, representing a node in anexisting tree, or it may be any kind of JAXP Source object such as a StreamSourceSAXSource or DOMSource. |
setStackFrameMap | protected void setStackFrameMap(SlotManager map)(Code) | | Define the number of slots needed for local variables within the expression
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