Interface IXPathEvaluator
Namespace: Aspose.Html.Dom.XPath
Assembly: Aspose.HTML.dll (25.2.0)
The evaluation of XPath expressions is provided by Aspose.Html.Dom.XPath.IXPathEvaluator.
[DOMNoInterfaceObject]
[ComVisible(true)]
public interface IXPathEvaluatorMethods
CreateExpression(string, IXPathNSResolver)
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.
[DOMName("createExpression")]
IXPathExpression CreateExpression(string expression, IXPathNSResolver resolver)Parameters
expression string
The XPath expression string to be parsed.
resolver IXPathNSResolver
The resolver permits translation of all prefixes,
including the xml namespace prefix, within the XPath expression into
appropriate namespace URIs. If this is specified as null, any namespace
prefix within the expression will result in Aspose.Html.Dom.DOMException being
thrown with the code NAMESPACE_ERR.
Returns
The compiled form of the XPath expression.
Exceptions
INVALID_EXPRESSION_ERR: Raised if the expression is not legal according to the rules of the Aspose.Html.Dom.XPath.IXPathEvaluator.
NAMESPACE_ERR: Raised if the expression contains namespace prefixes which cannot be resolved by the specified Aspose.Html.Dom.XPath.IXPathNSResolver.
CreateNSResolver(Node)
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.
[DOMName("createNSResolver")]
IXPathNSResolver CreateNSResolver(Node nodeResolver)Parameters
nodeResolver Node
The node to be used as a context for namespace resolution.
Returns
Aspose.Html.Dom.XPath.IXPathNSResolver which resolves namespaces with respect to the definitions in scope for a specified node.
Evaluate(string, Node, IXPathNSResolver, XPathResultType, object)
Evaluates an XPath expression string and returns a result of the specified type if possible.
[DOMName("evaluate")]
IXPathResult Evaluate(string expression, Node contextNode, IXPathNSResolver resolver, XPathResultType type, object result)Parameters
expression string
The XPath expression string to be parsed and evaluated.
contextNode Node
The context is context node for the evaluation of this
XPath expression. If the Aspose.Html.Dom.XPath.IXPathEvaluator was obtained by casting the
Aspose.Html.Dom.Document then this must be owned by the same document and must be a
Aspose.Html.Dom.Document, Aspose.Html.Dom.Element, Aspose.Html.Dom.Attr, Aspose.Html.Dom.Text,
Aspose.Html.Dom.CDATASection, Aspose.Html.Dom.Comment, Aspose.Html.Dom.ProcessingInstruction,
or Aspose.Html.Dom.XPath.XPathNamespace node. If the context node is a Aspose.Html.Dom.Text or a
Aspose.Html.Dom.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 IXPathNSResolver
The resolver permits translation of all prefixes, including
the xml namespace prefix, within the XPath expression into appropriate namespace URIs.
If this is specified as null, any namespace prefix within the expression will result
in Aspose.Html.Dom.DOMException being thrown with the code NAMESPACE_ERR.
type XPathResultType
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 values of the
Aspose.Html.Dom.XPath.XPathResultType enum.
result object
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 Aspose.Html.Dom.XPath.IXPathResult.
Returns
The result of the evaluation of the XPath expression. For XPath 1.0 results, this object will be of type Aspose.Html.Dom.XPath.IXPathResult.
Exceptions
INVALID_EXPRESSION_ERR: Raised if the expression is not legal according to the rules of the Aspose.Html.Dom.XPath.IXPathEvaluator.
TYPE_ERR: Raised if the result cannot be converted to return the specified type.
NAMESPACE_ERR: Raised if the expression contains namespace prefixes which cannot be resolved by the specified Aspose.Html.Dom.XPath.IXPathNSResolver.
WRONG_DOCUMENT_ERR: The Node is from a document that is not supported by this Aspose.Html.Dom.XPath.IXPathEvaluator.
NOT_SUPPORTED_ERR: The Node is not a type permitted as an XPath context node or the request type is not permitted by this Aspose.Html.Dom.XPath.IXPathEvaluator.