TiXmlHandle Class Reference

A TiXmlHandle is a class that wraps a node pointer with null checks; this is an incredibly useful thing. More...

#include <tinyxml.h>

Public Member Functions

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

| TiXmlHandle TiXmlHandle::Child | ( | int | index | ) | const |

Return a handle to the "index" child.

The first child is 0, the second 1, etc.

Return a handle to the "index" child with the given name.

The first child is 0, the second 1, etc.

| TiXmlHandle TiXmlHandle::ChildElement | ( | int | index | ) | const |

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.

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.

| TiXmlElement* TiXmlHandle::Element | ( | | ) | const [inline] |

**Deprecated:**use ToElement. Return the handle as a TiXmlElement. This may return null.

References ToElement().

| TiXmlNode* TiXmlHandle::Node | ( | | ) | const [inline] |

**Deprecated:**use ToNode. Return the handle as a TiXmlNode. This may return null.

References ToNode().

| TiXmlText* TiXmlHandle::Text | ( | | ) | const [inline] |

**Deprecated:**use ToText() Return the handle as a TiXmlText. This may return null.

References ToText().

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

Return the handle as a TiXmlElement.

This may return null.

Referenced by Element().

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

Return the handle as a TiXmlNode.

This may return null.

Referenced by Node().

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

Return the handle as a TiXmlText.

This may return null.

Referenced by Text().

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

Return the handle as a TiXmlUnknown.

This may return null.

Referenced by Unknown().

| TiXmlUnknown* TiXmlHandle::Unknown | ( | | ) | const [inline] |

**Deprecated:**use ToUnknown() Return the handle as a TiXmlUnknown. This may return null.

References ToUnknown().

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

tinyxml.h

Generated by 1.6.2