TinyXML
Public Member Functions
TiXmlHandle Class Reference

#include <tinyxml.h>

List of all members.

Public Member Functions

 TiXmlHandle(TiXmlNode * _node)
 Create a handle from any node (at any depth of the tree.) This can be a null pointer.
 TiXmlHandle(const TiXmlHandle & ref)
 Copy constructor.
TiXmlHandle Child(const char * value, int index)
TiXmlHandle Child(int index)
TiXmlHandle ChildElement(const char * value, int index)
TiXmlHandle ChildElement(int index)
TiXmlElement * Element()
TiXmlHandle FirstChild()
 Return a handle to the first child node.
TiXmlHandle FirstChild(const char * value)
 Return a handle to the first child node with the given name.
TiXmlHandle FirstChildElement()
 Return a handle to the first child element.
TiXmlHandle FirstChildElement(const char * value)
 Return a handle to the first child element with the given name.
TiXmlNode * Node()
TiXmlHandle operator=(const TiXmlHandle & ref)
TiXmlText * Text()
TiXmlElement * ToElement()
TiXmlNode * ToNode()
TiXmlText * ToText()
TiXmlUnknown * ToUnknown()
TiXmlUnknown * Unknown()

Detailed Description

A TiXmlHandle is a class that wraps a node pointer with null checks; this is an incredibly useful thing. Note that TiXmlHandle is not part of the TinyXml DOM structure. It is a separate utility class.

Take an example:

	<Document>
		<Element attributeA = "valueA">
			<Child attributeB = "value1" />
			<Child attributeB = "value2" />
		</Element>
	<Document>
	

Assuming you want the value of "attributeB" in the 2nd "Child" element, it's very easy to write a *lot* of code that looks like:

	TiXmlElement* root = document.FirstChildElement( "Document" );
	if ( root )
	{
		TiXmlElement* element = root->FirstChildElement( "Element" );
		if ( element )
		{
			TiXmlElement* child = element->FirstChildElement( "Child" );
			if ( child )
			{
				TiXmlElement* child2 = child->NextSiblingElement( "Child" );
				if ( child2 )
				{
					// Finally do something useful.
	

And that doesn't even cover "else" cases. TiXmlHandle addresses the verbosity of such code. A TiXmlHandle checks for null pointers so it is perfectly safe and correct to use:

	TiXmlHandle docHandle( &document );
	TiXmlElement* child2 = docHandle.FirstChild( "Document" ).FirstChild( "Element" ).Child( "Child", 1 ).ToElement();
	if ( child2 )
	{
		// do something useful
	

Which is MUCH more concise and useful.

It is also safe to copy handles - internally they are nothing more than node pointers.

	TiXmlHandle handleCopy = handle;
	

What they should not be used for is iteration:

	int i=0; 
	while ( true )
	{
		TiXmlElement* child = docHandle.FirstChild( "Document" ).FirstChild( "Element" ).Child( "Child", i ).ToElement();
		if ( !child )
			break;
		// do something
		++i;
	}
	

It seems reasonable, but it is in fact two embedded while loops. The Child method is a linear walk to find the element, so this code would iterate much more than it needs to. Instead, prefer:

	TiXmlElement* child = docHandle.FirstChild( "Document" ).FirstChild( "Element" ).FirstChild( "Child" ).ToElement();

	for( child; child; child=child->NextSiblingElement() )
	{
		// do something
	}
	

Member Function Documentation

Child

TiXmlHandle TiXmlHandle::Child ( const char *  value,
int  index 
)  const
TiXmlHandle TiXmlHandle::Child ( int  index) const
TiXmlHandle TiXmlHandle::Child(const char * value, int index)

Return a handle to the "index" child with the given name. The first child is 0, the second 1, etc.

Return a handle to the "index" child. The first child is 0, the second 1, etc.

ChildElement

TiXmlHandle TiXmlHandle::ChildElement ( const char *  value,
int  index 
)  const
TiXmlHandle TiXmlHandle::ChildElement ( int  index) const
TiXmlHandle TiXmlHandle::ChildElement(const char * value, int index)

Return a handle to the "index" child element with the given name. The first child element is 0, the second 1, etc. Note that only TiXmlElements are indexed: other types are not counted.

Return a handle to the "index" child element. The first child element is 0, the second 1, etc. Note that only TiXmlElements are indexed: other types are not counted.

Element

TiXmlElement* TiXmlHandle::Element ( ) const [inline]
Deprecated:
use ToElement. Return the handle as a TiXmlElement. This may return null.

Node

TiXmlNode* TiXmlHandle::Node ( ) const [inline]
Deprecated:
use ToNode. Return the handle as a TiXmlNode. This may return null.

Text

TiXmlText* TiXmlHandle::Text ( ) const [inline]
Deprecated:
use ToText() Return the handle as a TiXmlText. This may return null.

ToElement

TiXmlElement* TiXmlHandle::ToElement ( ) const [inline]

Return the handle as a TiXmlElement. This may return null.

ToNode

TiXmlNode* TiXmlHandle::ToNode ( ) const [inline]

Return the handle as a TiXmlNode. This may return null.

ToText

TiXmlText* TiXmlHandle::ToText ( ) const [inline]

Return the handle as a TiXmlText. This may return null.

ToUnknown

TiXmlUnknown* TiXmlHandle::ToUnknown ( ) const [inline]

Return the handle as a TiXmlUnknown. This may return null.

Unknown

TiXmlUnknown* TiXmlHandle::Unknown ( ) const [inline]
Deprecated:
use ToUnknown() Return the handle as a TiXmlUnknown. This may return null.

The documentation for this class was generated from the following files: