RXmlEngXPathExpression Class Reference

#include <xml/dom/xmlengxpathexpression.h>

class RXmlEngXPathExpression

Public Member Enumerations
enum	TXmlEngXPathExpressionPartType { EFunction, EPrefix }

Public Member Functions
	RXmlEngXPathExpression()
void	Close()
IMPORT_C void	Destroy()
IMPORT_C RXmlEngXPathResult	EvaluateL(TXmlEngNode, const MXmlEngNamespaceResolver *)
IMPORT_C RXmlEngXPathResult	EvaluateWithDependenciesL(TXmlEngNode, RXmlEngNodeSet &, const MXmlEngNamespaceResolver *)
IMPORT_C void *	ExtendedContext()
IMPORT_C void	SetExtendedContext(void *)

Detailed Description

A compiled XPath expression is a textual expression transformed after syntactical analysis into some internal representation of the expression. The only missing element for evaluation of the expression is evaluation context: the context node (where to start) and an optional set of prefix-to-namespace bindings.

XPath Expressions are created and instantiated by the Evaluator:

Member Enumeration Documentation

Enum TXmlEngXPathExpressionPartType

XPath expression parts

Enumerator	Value	Description
EFunction
EPrefix

Constructor & Destructor Documentation

RXmlEngXPathExpression ( )

IMPORT_C

RXmlEngXPathExpression

(

)

Default constructor

Member Function Documentation

Close ( )

void

(

)

[inline]

Resets the compiled expression and frees the allocated memory

Destroy ( )

IMPORT_C void

Destroy

(

)

Resets the compiled expression and frees the allocated memory

EvaluateL ( TXmlEngNode, const MXmlEngNamespaceResolver * )

IMPORT_C RXmlEngXPathResult	EvaluateL	(	TXmlEngNode	aContextNode,
			const MXmlEngNamespaceResolver *	aResolver = NULL
		)	const

Evaluates this expression.

Parameters
aContextNode	The node relative to which the expression is evaluated.
aResolver	Not supported in current API. Reserved for future use.

Return Value: Result of evaluation

Leave Codes
KXmlEngErrXPathResult	Error evaluating expression
KXmlEngErrXPathSyntax	Error compiling expression
KErrNoMemory	Memory allocation error

EvaluateWithDependenciesL ( TXmlEngNode, RXmlEngNodeSet &, const MXmlEngNamespaceResolver * )

IMPORT_C RXmlEngXPathResult	EvaluateWithDependenciesL	(	TXmlEngNode	aContextNode,
			RXmlEngNodeSet &	aDependents,
			const MXmlEngNamespaceResolver *	aResolver = NULL
		)	const

Does the same thing as EvaluateL(), but also calculates the dependency list of the expression.

Parameters
aContextNode	The node relative to which the expression is evaluated.
aDependents	After the method has returned, contains set of nodes that the expression is dependent on.
aResolver	Not supported in current API. Reserved for future use.

Return Value: Result of evaluation

Leave Codes
KXmlEngErrXPathResult	Error evaluating expression
KXmlEngErrXPathSyntax	Error compiling expression
KErrNoMemory	Memory allocation error

ExtendedContext ( )

IMPORT_C void *

ExtendedContext

(

)

const

Gets extended context data for the expression currently being evaluated.

SetExtendedContext ( void * )

IMPORT_C void

SetExtendedContext

(

void *

aContext

)

Set context data for the expression currently being evaluated.

Extended Context is data set by API users and available for XPath extension functions. For more information: