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MXmlEngXPathExtensionFunction Class Reference

class MXmlEngXPathExtensionFunction

Provides an interface for an object to participate in the evaluation of XPath expression via a XPath function call.

Objects that implement the MXmlEngXPathExtensionFunction interface can be registered in a XmlEngXPathConfiguration object for global action (across all evaluations globally).

XmlEngXPathConfiguration::AddExtensionFunctionL() When the extension function is no longer required, it must be deregistered by calling XmlEngXPathConfiguration::RemoveExtensionFunction() .

Public Member Functions
TXmlEngEvaluationStatus	Evaluate ( MXmlEngXPathEvaluationContext *)
TInt	MaxArity ()
TInt	MinArity ()

Public Member Enumerations
enum	TXmlEngEvaluationStatus { ESucceeded , EError , EInvalidArgumentType , EInvalidArgumentNumber }

Member Functions Documentation

Evaluate(MXmlEngXPathEvaluationContext *)

TXmlEngEvaluationStatus

Evaluate

(

MXmlEngXPathEvaluationContext *

aEvalCtxt

)

[pure virtual]

Called to evaluate the extension function.

This function is called only if simple arity constraints (min/max number of arguments) are satisfied. The implementation of this function may need to check further that the types of arguments and their positions in the function call match function-specific requirements.

Parameters

MXmlEngXPathEvaluationContext * aEvalCtxt

Evaluation context, which contains data about arguments and provides a number of methods for setting the result of the extension function.

MaxArity()

TInt

MaxArity

(

)

[inline, virtual]

Gets the maximum number of arguments the function can take.

MinArity()

TInt

MinArity

(

)

[inline, virtual]

Gets the minimum number of arguments the function can take.

Member Enumerations Documentation

Enum TXmlEngEvaluationStatus

Evaluation status

Enumerators

ESucceeded	Evaluation was accomplished successfully
EError	An exceptional condition occurs
EInvalidArgumentType	Type of argument does not match function specification
EInvalidArgumentNumber	Number of arguments do not match function specification