Types of Handles

The following table lists the types of handles that can be returned by the API functions and have to be used as input parameters for those functions to work with them. When a function returns a handle, you have to verify that the value is not 0. All methods return a 0 (NULL-Handle) in case of an error:

Type of Handles	Returned by Functions	Description
Document	XmlCreateDocument XmlCreateDocumentFromFile XmlCreateDocumentFromXml	A document handle represents the virtual root node of an XML document. The children of this virtual document node are the top level nodes of the document. You can either iterate through those children or execute X-Path queries to query the whole document.
Node	XmlSelectSingleNode XmlGetItem XmlGetChildByIndex XmlCreateNode XmlCreateNodeFromXml	There are different types of XML nodes - to get an overview of those types, see the XML Basics section. XML Nodes can be queried with X-Path or can be accessed by iterating through a document. Nodes can be modified, deleted and added. An element node itself has child nodes - like the document node has it child nodes representing the top level nodes in the document.
NodeList	XmlGetChildNodes XmlSelectNodes	Nodelist handles store none, one or multiple node handles which can be accessed with the XmlGetItem function. So if you want to operate on a node in a nodelist you first have to get the node handle out of the list and operate on that handle.

Type of Handles

Returned by Functions

Description

Document

XmlCreateDocument

XmlCreateDocumentFromFile

XmlCreateDocumentFromXml

A document handle represents the virtual root node of an XML document. The children of this virtual document node are the top level nodes of the document. You can either iterate through those children or execute X-Path queries to query the whole document.

Node

XmlSelectSingleNode

XmlGetItem

XmlGetChildByIndex

XmlCreateNode

XmlCreateNodeFromXml

There are different types of XML nodes - to get an overview of those types, see the XML Basics section. XML Nodes can be queried with X-Path or can be accessed by iterating through a document. Nodes can be modified, deleted and added. An element node itself has child nodes - like the document node has it child nodes representing the top level nodes in the document.

NodeList

XmlGetChildNodes

XmlSelectNodes

Nodelist handles store none, one or multiple node handles which can be accessed with the XmlGetItem function. So if you want to operate on a node in a nodelist you first have to get the node handle out of the list and operate on that handle.