diff -r ebc84c812384 -r 46218c8b8afa Symbian3/PDK/Source/GUID-49A7E8FD-72DA-5D56-86BE-74AA9AAF7C02.dita --- a/Symbian3/PDK/Source/GUID-49A7E8FD-72DA-5D56-86BE-74AA9AAF7C02.dita Thu Mar 11 15:24:26 2010 +0000 +++ b/Symbian3/PDK/Source/GUID-49A7E8FD-72DA-5D56-86BE-74AA9AAF7C02.dita Thu Mar 11 18:02:22 2010 +0000 @@ -1,57 +1,57 @@ - - - - - -Using -XPath Extension FunctionThis topic explains how to use the XPath Extension Function API -to implement XPath functions and register them with the XML DOM Engine. -

Before you start, you must:

    -

  • understand XPath syntax and the concept of Document Object Model (DOM).

    • -

  • understand the architecture -and classes of the XML -DOM Engine component.

    • -
 -

XPath is a query language for exploring XML documents. You can -extend it with domain-specific functions or with general utility functions, -to add functionality to XPath queries.

- -Write a new class -that implements the MXmlEngXPathEvaluationContext interface. -This class represents the evaluation context. It processes the arguments -of the extension function and stores the result of the evaluation.

- -Write a new class -that implements the MXPathExtensionFunction interface. -This class represents the new extension function. The MXPathExtensionFunction::Evaluate() function -uses its MXmlEngXPathEvaluationContext parameter -to process input arguments and return a result. This result can be a set of -nodes, a number, a boolean or a string.

- -Create an instance -of the new extension function class. - -Create a TXmlEngExtensionFunctionDescriptor structure. -This structure contains a pointer to the new extension function, the -name of the function, and the optional namespace URI.

- -Register this instance -by calling the static TXmlEngXPathConfiguration::AddExtensionFunctionL() function. - -Use the new extension -function in an XPath query. - -Free your resources -as necessary. - - - -Searching -a DOM Tree using XPath + + + + + +Using +XPath Extension FunctionThis topic explains how to use the XPath Extension Function API +to implement XPath functions and register them with the XML DOM Engine. +

Before you start, you must:

    +

  • understand XPath syntax and the concept of Document Object Model (DOM).

    • +

  • understand the architecture +and classes of the XML +DOM Engine component.

    • +
+

XPath is a query language for exploring XML documents. You can +extend it with domain-specific functions or with general utility functions, +to add functionality to XPath queries.

+ +Write a new class +that implements the MXmlEngXPathEvaluationContext interface. +This class represents the evaluation context. It processes the arguments +of the extension function and stores the result of the evaluation.

+ +Write a new class +that implements the MXPathExtensionFunction interface. +This class represents the new extension function. The MXPathExtensionFunction::Evaluate() function +uses its MXmlEngXPathEvaluationContext parameter +to process input arguments and return a result. This result can be a set of +nodes, a number, a boolean or a string.

+ +Create an instance +of the new extension function class. + +Create a TXmlEngExtensionFunctionDescriptor structure. +This structure contains a pointer to the new extension function, the +name of the function, and the optional namespace URI.

+ +Register this instance +by calling the static TXmlEngXPathConfiguration::AddExtensionFunctionL() function. + +Use the new extension +function in an XPath query. + +Free your resources +as necessary. + + + +Searching +a DOM Tree using XPath \ No newline at end of file