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TiXmlHandle Class Reference

#include <tinyxml.h>

List of all members.


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 ).Element();
	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 ).Element();
		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" ).Element();

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

Definition at line 1313 of file tinyxml.h.


Public Member Functions

TiXmlHandle Child (const std::string &_value, int index) const
TiXmlHandle Child (int index) const
TiXmlHandle Child (const char *value, int index) const
TiXmlHandle ChildElement (const std::string &_value, int index) const
TiXmlHandle ChildElement (int index) const
TiXmlHandle ChildElement (const char *value, int index) const
TiXmlElementElement () const
 Return the handle as a TiXmlElement. This may return null.
TiXmlHandle FirstChild (const std::string &_value) const
TiXmlHandle FirstChild (const char *value) const
 Return a handle to the first child node with the given name.
TiXmlHandle FirstChild () const
 Return a handle to the first child node.
TiXmlHandle FirstChildElement (const std::string &_value) const
TiXmlHandle FirstChildElement (const char *value) const
 Return a handle to the first child element with the given name.
TiXmlHandle FirstChildElement () const
 Return a handle to the first child element.
TiXmlNodeNode () const
 Return the handle as a TiXmlNode. This may return null.
TiXmlHandle operator= (const TiXmlHandle &ref)
TiXmlTextText () const
 Return the handle as a TiXmlText. This may return null.
 TiXmlHandle (const TiXmlHandle &ref)
 Copy constructor.
 TiXmlHandle (TiXmlNode *node)
 Create a handle from any node (at any depth of the tree.) This can be a null pointer.
TiXmlUnknownUnknown () const
 Return the handle as a TiXmlUnknown. This may return null;.

Private Attributes

TiXmlNodenode

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

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