Evaluates an XPath expression string and returns a result of the
specified type if possible.
Returns:
The result of the evaluation of the XPath expression.For XPath
1.0 results, this object will be of type
XPathResult
.
Parameters:
-
expression - The XPath expression string to be parsed and
evaluated.
-
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.
-
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
.
-
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.
-
result - The
result
specifies a specific result
object which may be reused and returned by this method. If this is
specified as
null
or 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
.
Throws:
-
XPathException - INVALID_EXPRESSION_ERR: Raised if the expression is not legal
according to the rules of the
XPathEvaluator
i
TYPE_ERR: Raised if the result cannot be converted to return the
specified type.
-
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
.