#include <xml/dom/xmlengxpathextensionfunction.h>
| class MXmlEngXPathExtensionFunction |
| Public Member Enumerations | |
|---|---|
| enum | TXmlEngEvaluationStatus { ESucceeded, EError, EInvalidArgumentType, EInvalidArgumentNumber } |
| Public Member Functions | |
|---|---|
| pure virtual TXmlEngEvaluationStatus | Evaluate(MXmlEngXPathEvaluationContext *) |
| virtual TInt | MaxArity() |
| virtual TInt | MinArity() |
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).
See also: XmlEngXPathConfiguration::AddExtensionFunctionL()
When the extension function is no longer required, it must be deregistered by calling XmlEngXPathConfiguration::RemoveExtensionFunction().
Evaluation status
| Enumerator | Value | Description |
|---|---|---|
| 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 |
| 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 | |
|---|---|
| aEvalCtxt | Evaluation context, which contains data about arguments and provides a number of methods for setting the result of the extension function. |
| TInt | MaxArity | ( | ) | [inline, virtual] |
Gets the maximum number of arguments the function can take.
| TInt | MinArity | ( | ) | [inline, virtual] |
Gets the minimum number of arguments the function can take.